Artículos de revistas: "Volatile fatty acids"

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Chughtai, Muhammad Farhan Jahangir, Imran Pasha, Faqir Muhammad Anjum y Muhammad Adnan Nasir. "Characterization of Sorghum and Millet with Special Reference to Fatty Acid and Volatile Profile." Turkish Journal of Agriculture - Food Science and Technology 3, n.º 7 (7 de junio de 2015): 515. http://dx.doi.org/10.24925/turjaf.v3i7.515-521.283.

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Sorghum and millet are important food staples in semi-arid tropics of Asia and Africa. Sorghum and millet are cereal grains that have prospective to be used as substitute to wheat flour for celiac patients. These are considered as the good source of many important and essential fatty acids. The volatile profiling of these two important crops is comparable to other cereals as well. The present study was an effort to explore biochemical composition of commercially available sorghum and millet varieties with special reference to their fatty acid and volatile profiling. Chemical composition of sorghum and millet was determined according to respective methods. Fatty acid methyl esters were prepared and then subjected to GC-FID for fatty acids analysis. The results indicated that both sorghum and millet oils are rich in essential fatty acids comprising mono and polyunsaturated fatty acids. Main fatty acids that are identified in current study includes palmitic acid, oleic acid, palmitoleic acid, behenic acid, linoleic acid, linoleic acid, stearic acid, myristic acid, etc. On the other hand volatile compounds from sorghum and millet were determined by preparing their respective volatile samples by using calvenger apparatus with suitable volatile extracting solvent. Volatile samples were then subjected to GC-MS analysis and respected results were compared with NIST library. About 30 different volatiles were identified in millet varieties while 35 different compounds were discovered in sorghum varieties belonging to aldehydes, ketones, benzene derivatives, esters, alcohols, sulphur compounds.

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Khrisanapant, Kebede, Leong y Oey. "A Comprehensive Characterisation of Volatile and Fatty Acid Profiles of Legume Seeds". Foods 8, n.º 12 (6 de diciembre de 2019): 651. http://dx.doi.org/10.3390/foods8120651.

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Legumes are rich in unsaturated fatty acids, which make them susceptible to (non) enzymatic oxidations leading to undesirable odour formation. This study aimed to characterise the volatile and fatty acid profiles of eleven types of legumes using headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) and GC coupled with a flame ionisation detector (GC-FID), respectively. Volatile aldehydes, alcohols, ketones, esters, terpenes and hydrocarbons were the chemical groups identified across all the legumes. The lipids comprised palmitic, stearic, oleic, linoleic and α-linolenic acids, with unsaturated fatty acids comprising at least 66.1% to 85.3% of the total lipids for the legumes studied. Multivariate data analysis was used to compare volatile and fatty acid profiles between legumes, which allow discriminant compounds pertinent to specific legumes to be identified. Results showed that soybean, chickpea and lentil had distinct volatile and fatty acid profiles, with discriminating volatiles including lactone, ester and ketone, respectively. While all three Phaseolus cultivars shared similar volatile profiles, 3-methyl-1-butanol was found to be the only volatile differentiating them against the other eight legumes. Overall, this is the first time a multivariate data analysis has been used to characterise the volatile and fatty acid profiles across different legume seeds, while also identifying discriminating compounds specific for certain legume species. Such information can contribute to the creation of legume-based ingredients with specific volatile characteristics while reducing undesirable odours, or potentially inform relevant breeding programs.

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Wang, Zhiwei, Weiwu Wang, Ping Li, Yaping Leng y Jinhua Wu. "Continuous Production of Volatile Fatty Acids (VFAs) from Swine Manure: Determination of Process Conditions, VFAs Composition Distribution and Fermentation Broth Availability Analysis". Water 14, n.º 12 (16 de junio de 2022): 1935. http://dx.doi.org/10.3390/w14121935.

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For pollution control and waste utilization, a promising future direction is to obtain high-value carbon sources from organic waste. In this experiment, swine manure was efficiently converted into high concentration volatile fatty acids through continuous hydrolysis-acidification bioreactors. This study determined the process conditions, the composition distribution of volatile fatty acids and the availability of fermentation broth. The results showed that the reactor with a hydraulic retention time of 1.5 days had the optimal production performance of volatile fatty acids. The highest hydrolysis degree (62.2%) and acidification degree (42.5%) were realized in this reactor at the influent soluble chemical oxygen demand of 5460 mg/L. Furthermore, when the influent soluble chemical oxygen demand was 7660 mg/L, volatile fatty acids of 6065 mg-COD/L could be produced stably, and the proportion of volatile fatty acids in soluble chemical oxygen demand was the largest (75%). Additionally, the fermentation broth rich in volatile fatty acids could be applied to deep nitrogen and phosphorus removal. This work provides a productive approach to resource recovery from swine manure.

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van der Wielen, Paul W. J. J., Steef Biesterveld, Len J. A. Lipman y Frans van Knapen. "Inhibition of a Glucose-Limited Sequencing Fed-Batch Culture ofSalmonella enterica Serovar Enteritidis by Volatile Fatty Acids Representative of the Ceca of Broiler Chickens". Applied and Environmental Microbiology 67, n.º 4 (1 de abril de 2001): 1979–82. http://dx.doi.org/10.1128/aem.67.4.1979-1982.2001.

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ABSTRACT The effects of concentrations of volatile fatty acids on an anaerobic, glucose-limited, and pH-controlled growing culture ofSalmonella enterica serovar Enteritidis were studied. Suddenly increasing volatile fatty acids to the concentrations representative of the ceca of 15-day-old broiler chickens caused washout of serovar Enteritidis. In contrast, a sudden increase to the volatile fatty acid concentrations representative of the ceca of younger broiler chickens caused a reduction in the biomass but not washout. Gradually increasing volatile fatty acids caused a gradual decrease in the biomass of serovar Enteritidis. We conclude that the concentrations of volatile fatty acids present in the ceca of broilers with a mature microflora can cause washout of serovar Enteritidis in an in vitro system mimicking cecal ecophysiology.

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Rahim, Ahmad Fitri Abd, Shamsul Rahman Mohamed Kutty y Ezerie Henry Ezechi. "Volatile Fatty Acids Production through Degradation of Biomass by Anaerobic Digestion (Mesophilic and Thermophilic)". Applied Mechanics and Materials 567 (junio de 2014): 172–76. http://dx.doi.org/10.4028/www.scientific.net/amm.567.172.

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Volatile fatty acids (VFAs) are fatty acids with a carbon chain of six carbons or fewer and usually referred to as short-chain fatty acids (SCFA). Degradation of biomass through anaerobic digestion will produce volatile fatty acid (VFAs) through anaerobic digestion process. The volatile fatty acids obtained can be recovered and used to produce methyl or ethyl esters which, could be advantageously used as additive for biodiesel [1]. Anaerobic digestion is a biological process that can degrade waste organic material by concerted action of a wide range of microorganisms in the absence of oxygen. The objective of this study is to degrade the biomass through anaerobic digestion for the production of volatile fatty acids by two different temperatures condition which are mesophilic and thermophilic; 35°C and 55°C respectively. The production of volatile fatty acids was optimized by varying the cycle period of the digestion process with the concentration of Mixed Liquor Suspended Solid (MLSS) maintained at 8000 mg/L for each cycle. The degradation of biomass was carried out using anaerobic sludge digester which 2L of biomass was digested from day 1 until day 24 (cycle period). The tests of MLSS and Mixed Liquor Volatile Suspended Solid (MLVSS) was conducted by Standard Method 2540-D while test for VFAs was conducted through Standard Method 8196. The highest production of volatile fatty acids was obtained in day 5 of cycle period where the concentration is 441 mg/L as acetic acid (HOAC).

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Wajs-Bonikowska, Anna, Karol Olejnik, Radosław Bonikowski y Piotr Banaszczak. "Analysis of Volatile Components, Fatty Acids, and Phytosterols of Abies Koreana growing in Poland". Natural Product Communications 8, n.º 9 (septiembre de 2013): 1934578X1300800. http://dx.doi.org/10.1177/1934578x1300800928.

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Extracts and essential oils from seeds as well as essential oils from cone scales and needles with twigs of the Abies koreana population were studied. An analysis of Korean fir essential oils allowed us to determine 147 volatile compounds. The identified compounds constituted 97–99% of the seed, cone and needle oils. The main volatile in the seed and needle oils was limonene (56.6% and 23.4%, respectively), while the predominant volatile in cone oils was α-pinene (51.2%). Korean fir seeds provided a rich source of both essential oil (3.8–8.5%) and extract, which was isolated with a 24.5% yield and contained numerous groups of fatty acids and phytosterols (414 μg/100g extract). The most prominent fatty acids were unsaturated, among which linoleic (41.2%) and oleic (31.2%) fatty acid were the main ones while the dominant sterols were isomers of ergostadienol and β-sitosterol. A. koreana seeds, cones and needles are a source of many volatile bioactive compounds while the seed extract, with a pleasant scent, contained not only volatiles, but also fractions rich in fatty acids and phytosterols. These facts make A. koreana essential oils and especially the seed extract potential components of cosmetics.

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Kim, J. O., I. Somiya, E. B. Shin, W. Bae, S. K. Kim y R. H. Kim. "Application of membrane-coupled anaerobic volatile fatty acids fermentor for dissolved organics recovery from coagulated raw sludge". Water Science and Technology 45, n.º 12 (1 de junio de 2002): 167–74. http://dx.doi.org/10.2166/wst.2002.0423.

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To investigate the treatment performance of membrane-coupled anaerobic volatile fatty acids fermentor system, the effects of operational parameters for volatile fatty acids production were evaluated through experiments and a mathematical model. The volatile fatty acids recovery ratio was largely affected by the change of hydraulic retention time, reaching its maximum value at 12 hrs. Over the range of hydraulic retention time 8 to 96 hrs, the volatile fatty acids recovery ratio decreased with the increase of hydraulic retention time above 12 hrs, while the ratio of mineralization and gasification increased. Hydraulic retention time and membrane filtration ratio should be maintained less than 1 day and above 0.9, respectively, to attain over 40% of organic materials recovery ratio at 10 days of solids retention time. When the hydrolysis rate constant was 0.01 hr−1, the organic loading rate should be maintained at above 1.0 (kgC/m3/day) to attain over 45% of volatile fatty acids recovery ratio. Based on experimental and simulated results, membrane-coupled anaerobic volatile fatty acids fermentor system was thought to be effective for dissolved organics recovery from coagulated sewage sludge.

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Najdoska-Bogdanov, Menče, Jane B. Bogdanov y Marina Stefova. "Simultaneous Determination of Essential Oil Components and Fatty Acids in Fennel using Gas Chromatography with a Polar Capillary Column". Natural Product Communications 10, n.º 9 (septiembre de 2015): 1934578X1501000. http://dx.doi.org/10.1177/1934578x1501000933.

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Cultivated and wild growing samples of fennel ( Foeniculum vulgare Mill., Apiaceae) from R. Macedonia were studied for their volatiles and fatty acid composition. The main essential oil components isolated via hydrodistillation were: trans-anethole (>80%), estragole (<6%), limonene (<6%), anisaldehyde (<1%) and 0.5 % fenchone. An alternative method for characterization of both the non-polar volatile and non volatile fractions was developed using n-hexane and dichloromethane (3:1, v/v) in a Soxhlet extraction followed by transesterification. The obtained extracts were then characterized and the dominant fatty acid was 18:1 (petroselinic and oleic acid) 75.0–82.8 %, followed by 18:2 (linoleic acid) 10.8–16.2% and other fatty acids: palmitic (4.3–6.9%), stearic (1.2–1.7%) and myristic (0–2.9%). The results for the volatile fraction after Soxhlet extraction and transesterification did not significantly differ from results obtained after hydrodistillation, especially for the main components ( trans-anethole, estragole, fenchone and limonene), implying that the developed method can be used for simultaneous determination of volatiles and fatty acids.

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Borowski, Sebastian y Marcin Kucner. "The use of sugar beet pulp stillage for co-digestion with sewage sludge and poultry manure". Waste Management & Research 37, n.º 10 (10 de abril de 2019): 1025–32. http://dx.doi.org/10.1177/0734242x19838610.

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The anaerobic mesophilic co-digestion of sugar beet pulp stillage with poultry manure and municipal sewage sludge was investigated in this study. The sugar beet pulp stillage (SBPS) mono-digestion failed owing to an accumulation of volatile fatty acids, leading to a pH value lower than 5.5. A 20% addition of poultry manure to stillage allowed for stable digestion performance despite high volatile fatty acid (total volatile fatty acids) concentrations of 5500–8500 g m−3 with propionic acid being the predominant one and constituting 72%–76% total volatile fatty acids. For this mixture, the maximum methane production of 418 dm3 kgVSfed−1 was achieved when the reactor was operated at a solids retention time of 20 days and an organic loading rate of 4.25 kgVS m−3 d−1. The co-digestion of stillage with 60% municipal sewage sludge gave the average methane yield of around 357 dm3 kgVSfed−1 for all operational conditions applied, however, the methane percentage of biogas (up to 70%) was far greater than the corresponding values obtained for sugar beet pulp stillage–poultry manure co-digestion. Neither ammonia nor volatile fatty acids destabilised the biogas production, and the volatile fatty acid profile showed the dominance of acetic acid (72%–82% total volatile fatty acids) followed by propionic and butyric acids.

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Akayzin, E. S., A. S. Metelev y A. E. Akayzina. "INDICATORS OF VOLATILE FATTY ACIDS IN DIFFERENTIAL DIAGNOSTICS OF INFECTED AND STERILE PANCREONECROSIS". Russian Clinical Laboratory Diagnostics 64, n.º 11 (15 de noviembre de 2019): 644–48. http://dx.doi.org/10.18821/0869-2084-2019-64-11-644-648.

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The aim of the study was to assess the information content of volatile fatty acid parameters for the differential diagnosis of infected and sterile pancreatic necrosis. The work is based on the results of examination and treatment of 34 patients with pancreatic necrosis. The analysis of concentrations of volatile fatty acids: acetic, propionic, butyric and isovaleric was carried out on an automated gas chromatograph «Crystallux-4000» with a capillary column «HP-FFAP» and flame ionization detector. The indicators of acetic, propionic, butyric, isovaleric acid and the sum of volatile fatty acids are statistically significantly higher in patients with infected pancreatic necrosis compared with the indicators of volatile fatty acids in patients with sterile pancreatic necrosis. Volatile fatty acid values can be used for the differential diagnosis of infected and sterile pancreatic necrosis

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Pavan, Enrique, Yangfan Ye, Graham T. Eyres, Luis Guerrero, Mariza G. Reis, Patrick Silcock, Patricia L. Johnson y Carolina E. Realini. "Relationships among Consumer Liking, Lipid and Volatile Compounds from New Zealand Commercial Lamb Loins". Foods 10, n.º 5 (20 de mayo de 2021): 1143. http://dx.doi.org/10.3390/foods10051143.

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Loin sections (m. Longissimus lumborum) were collected at slaughter from forty-eight lamb carcasses to evaluate consumer-liking scores of six types of typical New Zealand commercial lamb and to understand the possible underlying reasons for those ratings. A consumer panel (n = 160) evaluated tenderness, juiciness, flavor liking, and overall liking of the different types of lamb loins. Consumer scores differed among the types of lamb meat for all the evaluated attributes (p < 0.05). Further segmentation based on overall liking scores showed two consumer clusters with distinct ratings. Correlation and external preference map analyses indicated that one consumer cluster (n = 75) liked lamb types that had lower total lipid content, a lower proportion of branched-chain fatty acids, oleic and heptadecanoic acids; and a higher proportion of polyunsaturated fatty acids and volatile compounds (green and fruity descriptors). Consumer liking of the other segment (n = 85) was less influenced by fatty acids and volatiles, except hexanoic, heptanoic and octanoic acids (rancid, fatty, and sweaty descriptors). Thus, the fatty acid profile and the volatile compounds derived from their oxidation upon cooking seem to be a stronger driver of consumer liking of lamb for some consumers than others.

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van der Wielen, Paul W. J. J., Steef Biesterveld, Servé Notermans, Harm Hofstra, Bert A. P. Urlings y Frans van Knapen. "Role of Volatile Fatty Acids in Development of the Cecal Microflora in Broiler Chickens during Growth". Applied and Environmental Microbiology 66, n.º 6 (1 de junio de 2000): 2536–40. http://dx.doi.org/10.1128/aem.66.6.2536-2540.2000.

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ABSTRACT It is known that volatile fatty acids can inhibit growth of species of the family Enterobacteriaceae in vitro. However, whether these volatile fatty acids affect bacterial populations in the ceca of chickens is unknown. Therefore, a study was conducted to investigate if changes in volatile fatty acids in ceca of broiler chickens during growth affect bacterial populations. Results showed that members of theEnterobacteriaceae and enterococci are present in large numbers in 3-day-old broilers and start to decrease when broilers grow older. Lactobacilli are present in large numbers as well in 3-day-old broilers, but they remain stable during the growth of broilers. Acetate, butyrate, and propionate increase from undetectable levels in 1-day-old broilers to high concentrations in 15-day-old broilers, after which they stabilize. Significant negative correlations could be calculated between numbers of Enterobacteriaceae and concentrations of undissociated acetate, propionate, and butyrate. Furthermore, pure cultures of Enterobacteriaceae isolated from the ceca were grown in the presence of volatile fatty acids. Growth rates and maximal optical density decreased when these strains grew in the presence of increasing volatile fatty acid concentrations. It is concluded that volatile fatty acids are responsible for the reduction in numbers of Enterobacteriaceae in the ceca of broiler chickens during growth.

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Swiatkiewicz, Justyna, Radoslaw Slezak, Liliana Krzystek y Stanislaw Ledakowicz. "Production of Volatile Fatty Acids in a Semi-Continuous Dark Fermentation of Kitchen Waste: Impact of Organic Loading Rate and Hydraulic Retention Time". Energies 14, n.º 11 (21 de mayo de 2021): 2993. http://dx.doi.org/10.3390/en14112993.

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The aim of the study was to evaluate the possibility of using the process of dark fermentation to convert kitchen waste into valuable volatile fatty acids in a semi-continuous process at different values of the organic loading rate (2.5 and 5.0 gVS/(L × d)) and hydraulic retention time (5 and 10 d) using anaerobic mixed microbial consortia. The experiments were performed in a bioreactor of working volume 8L with pH control. The maximum volatile fatty acids yield in a steady state (22.3 g/L) was achieved at the organic loading rate of 5.0 gVS/(L × d) and HRT of 10 days. The main products of dark fermentation were acetic and butyric acids, constituting, respectively, 35.2–47.7% and 24.1–30.0% of all identified volatile fatty acids. Additionally, at the beginning of the fermentation and in a steady-state condition, the microbial population analysis (16S rDNA) of the fermentation mixture with the most effective volatile fatty acids generation has been performed to monitor the DF microflora development. The dominant microorganisms at a phylum level in a steady state were Firmicutes (44.9%) and Bacteroidetes (30.1%), which indicate the main role of those phyla in the volatile fatty acids synthesis.

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PROCHÁZKA, L., F. KVASNIČKA y A. ŠTECHOVÁ. "Determination of volatile fatty acids in molasses." Kvasny Prumysl 32, n.º 2 (1 de febrero de 1986): 33–36. http://dx.doi.org/10.18832/kp1986008.

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Fufachev, Egor V., Bert M. Weckhuysen y Pieter C. A. Bruijnincx. "Tandem catalytic aromatization of volatile fatty acids". Green Chemistry 22, n.º 10 (2020): 3229–38. http://dx.doi.org/10.1039/d0gc00964d.

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Righetti, Edoardo, Simone Nortilli, Francesco Fatone, Nicola Frison y David Bolzonella. "A Multiproduct Biorefinery Approach for the Production of Hydrogen, Methane and Volatile Fatty Acids from Agricultural Waste". Waste and Biomass Valorization 11, n.º 10 (26 de marzo de 2020): 5239–46. http://dx.doi.org/10.1007/s12649-020-01023-3.

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Abstract A pilot scale biorefinery platform for the treatment of agro-waste and the production of hydrogen, methane and volatile fatty acids was studied in real environment. The system adopted was a two stage anaerobic process where hydrogen and volatile fatty acids were produced in the first phase (fermentation) and methane in the second one (digestion). The study demonstrated the possibility to produce a biogas composed by hydrogen and methane (10% and 55%, respectively) while recovering volatile fatty acids. The yield for acids production was equivalent to 0.13 gVFA/gTVS (as COD) with acetate and butyrate as dominant observed species. Graphic Abstract

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Akayzin, E. S. y A. E. Akayzina. "Indicators of volatile fatty acids for differential diagnostics of nfected of pancreatic necrosis complicated by retroperitoneal phlegmon". Russian Clinical Laboratory Diagnostics 66, n.º 5 (23 de mayo de 2021): 310–14. http://dx.doi.org/10.51620/0869-2084-2021-66-5-310-314.

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The aim of the study was to assess the informative value of volatile fatty acid parameters for the differential diagnosis of infected pancreatic necrosis (IPN), complicated by retroperitoneal cellulitis. The work was based on the results of examination and treatment of 44 patients with infected pancreatic necrosis. The analysis of concentrations of volatile fatty acids: acetic, propionic, butyric and isovalerianic was carried out on a Kristallux-4000 automated gas chromatograph with an HP-FFAP capillary column and a flame ionization detector. The indicators of acetic acid and the amount of volatile fatty acids were statistically significantly higher in patients with infected pancreatic necrosis with total retroperitoneal phlegmons in comparison with the indicators of volatile fatty acids in patients with infected pancreatic necrosis with paracolic phlegmons and in comparison with indicators of volatile fatty acids in patients with infected pancreatic necrosis phlegmons. The indicators of acetic acid and the amount of VFA can be used as additional criteria for the differential diagnosis of IPN complicated by phlegmons of the retroperitoneal tissue.

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Oliveira, J. M., P. Oliveira, R. L. Baumes y M. O. Maia. "Volatile and Glycosidically Bound Composition of Loureiro and Alvarinho Wines". Food Science and Technology International 14, n.º 4 (agosto de 2008): 341–53. http://dx.doi.org/10.1177/1082013208097442.

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Composition of Loureiro and Alvarinho wines from the Vinhos Verdes region, regarding free volatile compounds as well as glycosidically bound aroma precursors, was exhaustively determined by gas chromatography—mass spectrometry after adsorption on XAD-2 resin. On the whole, were identified and quantified 120 volatile compounds in the free fraction and 77 glycosidically bound compounds, belonging to C6-compounds, alcohols, fatty acids ethyl esters, esters of organic acids, acetates, monoterpenic alcohols, monoterpenic oxides and diols, C13-norisoprenoids, volatile phenols, volatile fatty acids, and carbonyl compounds. Globally, the wines of the two cultivars present similar composition on volatiles. However, regarding varietal compounds, Loureiro wines were richer than Alvarinho ones with respect to C6-compounds and monoterpenic compounds, occurring the opposite for volatile phenols. It was also demonstrated that wines of both varieties might benefit the aroma reserve, present as glycoconjugates, as it is susceptible of being technologically explored. Linalool, Ho-trienol, (α-terpineol, contributing with fruity and floral notes, and (β-damascenone mostly for Alvarinho, confering tropical fruit notes, are the varietal compounds which may particularly influence the aroma of these wines. Respecting fermentative compounds, Alvarinho is also particularly rich in fatty acids ethyl esters related to lipid metabolism and acetates of fusel alcohols, which can provide it a fruity character; Loureiro contains higher levels of esters of organic acids and 2-phenylethanol, conferring fruity and floral notes. Sensory analysis agreed with chemical analyses showing a pronounced tree and tropical fruit character for Alvarinho wines while Loureiro wines present more intense citrus fruit notes.

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Guo, Li, Mingjie Chen, Yaling Guo y Zhi Lin. "Variations in Fatty Acids Affected Their Derivative Volatiles during Tieguanyin Tea Processing". Foods 11, n.º 11 (26 de mayo de 2022): 1563. http://dx.doi.org/10.3390/foods11111563.

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Fatty acids (FAs) are important precursors of oolong tea volatile substances, and their famous derivatives have been shown to be the key aroma components. However, the relationship between fatty acids and their derivatives during oolong tea production remains unclear. In this study, fresh Tieguanyin leaves were manufactured into oolong tea and green tea (control), and fatty acids and fatty acid-derived volatiles (FADV) were extracted from processed samples by the sulfuric acid–methanol method and solvent-assisted flavor evaporation (SAFE), respectively. The results showed that unsaturated fatty acids were more abundant than saturated fatty acids in fresh leaves and decreased significantly during tea making. Relative to that in green tea, fatty acids showed larger variations in oolong tea, especially at the green-making stage. Unlike fatty acids, the FADV content first increased and then decreased. During oolong tea manufacture, FADV contents were significantly and negatively correlated with total fatty acids; during the green-making stage, methyl jasmonate (MeJA) content was significantly and negatively correlated with abundant fatty acids except steric acid. Our data suggest that the aroma quality of oolong tea can be improved by manipulating fatty acid transformation.

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SOLTANBEIGI, Amir, Harun DIRAMAN y Mohammad Bagher HASSANPOURAGHDAM. "Chemical components of volatile oil and fatty acids of wild Bunium persicum (Boiss.) B. Fedtsch. and cultivated Cuminum cyminum L. populations". Acta agriculturae Slovenica 117, n.º 2 (14 de julio de 2021): 1. http://dx.doi.org/10.14720/aas.2021.117.2.1335.

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<p>Volatile oil and fatty acids components of six various populations of wild Bunium persicum Boiss. (Bam and Zirkuh/Iran) and cultivated Cuminum cyminum L. (Rayen/Iran; Cukurcak, Taskopru and Asagialicomak/Turkey) species were investigated. The volatile oil content of Bam and Zirkuh populations were 3.9 and 4.7 %, respectively. The analysis of volatile oils by the GC/FID-MSD showed that γ-terpinene (33.62-39.62 %), cuminal (17.9-19.3 %), o-cymene (5.3-11.1 %), benzenemethanol, α-methyl- (7.4-9.5 %), 1-phenyl-1-butanol (6.4-8.4 %) and limonene (6.4-8.6 %) were the major components of B. persicum populations. Rayen, Cukurcak, Taskopru and Asagialicomak populations of C. cyminum had 2.6, 2.2, 2.0 and 2.5 % of volatile oil, respectively. Cuminal (22.8-37.6 %), benzenemethanol, α-methyl- (5.3-22.6 %), γ-terpinene (16.7-19.4 %), β-pinene (11.2-11.9 %) and 1-phenyl-1-butanol (5.4-12.5 %) were identified as the main components of C. cyminum. Fatty acids were detected by the GC/FID. In total, 15 fatty acids were characterised in B. persicum populations from Iran. Petroselinic acid (26.3-52.6 %), lauric acid (16.2-37.0 %) and linoleic acid (18.3-33.0 %) were the predominant fatty acids identified in Iranian populations. C. cyminum populations were rich in the same fatty acids but, the order was: petroselinic acid (47.5-55.5 %), linoleic acid (22.5-25.4 %) and lauric acid (13.4-24.2 %). Monounsaturated fatty acids (27.4-56.2 %) were the major subgroup. Overall, B. persicum populations from Iran and C. cyminum from Turkey were almost similar in fatty acids profile although they had wide diversity in the volatile oils compositional profile.</p>

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Wang, Dong, Hafiz Umer Javed, Ying Shi, Safina Naz, Sajid Ali y Chang-Qing Duan. "Impact of Drying Method on the Evaluation of Fatty Acids and Their Derived Volatile Compounds in ‘Thompson Seedless’ Raisins". Molecules 25, n.º 3 (30 de enero de 2020): 608. http://dx.doi.org/10.3390/molecules25030608.

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Air- and sun-dried raisins from Thompson Seedless (TS) grapes were analyzed under GC/MS to evaluate fatty acids (FAs) and their derived volatile compounds, coming from unsaturated fatty acids oxidation. A total of 16 FAs were identified in TS raisins, including 10 saturated fatty acids (SFAs) and 6 unsaturated fatty acids (USFAs). The contents of C18:0, C15:0, and C16:0 among SFAs and C18:3, C18:2 and C18:1 in USFAs were significantly higher. Furthermore, USFAs such as C16:1 and C20:1 were only identified in air-dried raisins. The principal component analysis showed the increased content of FAs and FA-derived compounds were in air-dried and sun-dried raisins, respectively. Among FA-derived compounds, 2-pentyl furan, 3-octen-2-one, 1-hexanol and heptanoic acid were more potent. This study shows that air-drying is more favorable for the production of fatty acids (SFAs and USFAs), whereas sun-drying is more advantageous in terms of fatty acid-derived volatiles.

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Aznury, Martha, Tjandra Setiadi y Adi Pancoro. "Pengaruh sumber karbon terhadap produksi bioplastik polihidroksialkanoat (PHA) dengan ralstonia eutropha". Jurnal Teknik Kimia Indonesia 9, n.º 1 (2 de octubre de 2018): 28. http://dx.doi.org/10.5614/jtki.2010.9.1.4.

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Bioplastic Polyhidroxyalknoate (PHA) is a polyester type bioplastic with physicochemical properties resemble to those of polypropilen from petroleum. PHA production was investigated to determine the effect of carbon source on the fermentation process by Ralstonia eutropha. Specifically, Ralstonia eutropha was cultivated in a batch bioreactor to show the dynamics of P(3HB-co-3HV) copolymer production from glucose or fructose as C source. In adition, the effect of volatile fatty acids addition, as stimulator to the copolymer production, was also studied. The operating conditions in a 7 L bioreactor were at temperature 30 oC and pH 7.0. The concentration of carbon source glucose or fructose was 40 g/L, and after 20 hour fermentation, volatile fatty acids were added. With volatile fatty acids addition, the resulting fructose fermentation had PHA content of 32.78%, in which the HV percentage was 11.78%. Meanwhile, the fermentation of glucose, stimulated by volatile fatty acids, gave PHA as much as 20.19% with HV percentage of 8.71%. Therefore,, the Ralstonia eutropha fermentation of fructose as the carbon source gave a higher yield than glucose. Keywords: Volatil Fatty Acid, Fructose, Glucose, PHA, P(3HB-co-3HV), Ralstonia eutropha AbstrakBioplastik polihidroksialkanoat (PHA) adalah bioplastik dari kelompok poliester dengan sifat fisikokimia mirip dengan plastik polipropilen dari minyak bumi. Penelitian ini bertujuan untuk mempelajari pengaruh sumber karbon terhadap poduksi PHA yang dilakukan dengan proses fermentasi menggunakan Ralstonia eutropha. Ralstonia eutropha dikultivasi dalam bioreaktor batch untuk mempelajari dinamika produksi kopolimer P(3HB-co-3HV) dari sumber karbon glukosa atau fruktosa, serta mempelajari pengaruh sumber stimulator asam lemak volatil. Kondisi operasional fermentasi menggunakan bioreaktor 7 L adalah pada temperatur 30 oC dan pH 7. Konsentrasi sumber karbon glukosa atau fruktosa yang digunakan adalah 40 gr/L, dan setelah 20 jam fermentasi ditambahkan asam lemak volatil yang berfungsi sebagai stimulator dalam produksi P(3HB-co-3HV). Panen sel Ralstonia eutropha dilakukan setelah 60 jam. Hasil penelitian menunjukkan fermentasi Ralstonia eutropha dengan substrat fruktosa dan asam lemak volatil sebagai stimulator mempunyai kandungan PHA sebesar 32,78%, dengan kadar HV 11,78%. Pada pemberian substrat glukosa dan asam lemak volatil menunjukkan kandungan PHA sebesar 20,19%, dengan kadar HV 8.71%. Jadi fermentasi Ralstonia eutropha dengan menggunakan substrat fruktosa memberikan yield yang lebih tinggi dibandingkan menggunakan substrat glukosa.Kata Kunci: Asam lemak volatil, fruktosa, glukosa, PHA, P(3HB-co-3HV), Ralstonia eutropha

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23

Martínez-Castro, Isabel, Jesus Sanz, Lourdes Amigo, Mercedes Ramos y Pedro Martín-Alvarez. "Volatile components of Manchego cheese". Journal of Dairy Research 58, n.º 2 (mayo de 1991): 239–46. http://dx.doi.org/10.1017/s0022029900029782.

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SummaryVolatile components of four batches of Manchego cheese were studied throughout their ripening process. Samples were submitted to a micro simultaneous distillation-extraction procedure, and then analysed by capillary gas chromatography (GC) and combined GC and mass spectrometry. Among other components, four homologous series of compounds were found: free fatty acids, methyl ketones, ethyl and methyl esters of even fatty acids. Ripening stage can be approximately estimated from the concentrations of some components.

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24

Nickavar, Bahman, Faraz Mojab, Katayoun Javidnia y Mohammad Ali Roodgar Amoli. "Chemical Composition of the Fixed and Volatile Oils of Nigella sativa L. from Iran". Zeitschrift für Naturforschung C 58, n.º 9-10 (1 de octubre de 2003): 629–31. http://dx.doi.org/10.1515/znc-2003-9-1004.

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AbstractThe chemical composition of the extracted fixed oil (total fatty acid composition) and volatile oil of Nigella sativa L. seeds grown in Iran were determined by GC and GC/MS. Eight fatty acids (99.5%) and thirty- two compounds (86.7%) have been identified in the fixed and volatile oils, respectively. The main fatty acids of the fixed oil were linoleic acid (55.6%), oleic acid (23.4%), and palmitic acid (12.5%). The major compounds of the volatile oil were trans-anethole (38.3%), p-cymene (14.8%), limonene (4.3%), and carvone (4.0%).

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25

Bettencourt, Sara, Catarina Miranda, Tatiana A. Pozdniakova, Paula Sampaio, Ricardo Franco-Duarte y Célia Pais. "Single Cell Oil Production by Oleaginous Yeasts Grown in Synthetic and Waste-Derived Volatile Fatty Acids". Microorganisms 8, n.º 11 (17 de noviembre de 2020): 1809. http://dx.doi.org/10.3390/microorganisms8111809.

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Four yeast isolates from the species—Apiotrichum brassicae, Candida tropicalis, Metschnikowia pulcherrima, and Pichia kudriavzevii—previously selected by their oleaginous character and growth flexibility in different carbon sources, were tested for their capacity to convert volatile fatty acids into lipids, in the form of single cell oils. Growth, lipid yields, volatile fatty acids consumption, and long-chain fatty acid profiles were evaluated in media supplemented with seven different volatile fatty acids (acetic, butyric, propionic, isobutyric, valeric, isovaleric, and caproic), and also in a dark fermentation effluent filtrate. Yeasts A. brassicae and P. kudriavzevii attained lipid productivities of more than 40% (w/w), mainly composed of oleic (>40%), palmitic (20%), and stearic (20%) acids, both in synthetic media and in the waste-derived effluent filtrate. These isolates may be potential candidates for single cell oil production in larger scale applications by using alternative carbon sources, combining economic and environmental benefits.

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Lambert, Hélène, Claude Willemot, John E. Thompson y Joseph Makhlouf. "Identification of Isolated Membrane Major Volatiles of Fresh Tomato". HortScience 30, n.º 4 (julio de 1995): 814D—814. http://dx.doi.org/10.21273/hortsci.30.4.814d.

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This research is aimed at the identification of volatile compounds from the isolated membranes fractions, microsomes, and deteriosomes. Fractions were isolated from tomato pericarp by ultracentrifugation at 252,000x g during 1 hour, followed by 362,000x g during 12 hours. The supernatant was infiltrated through a membrane of 300,000 D cut off to concentrate the deteriosomes. The volatiles from the fractions were analyzed by dynamic headspace and GC-MS. Our results suggest that the isolated fractions contained most tomato volatiles. Analysis by GC-MS identified two groups: compounds originating from fatty acids [e.g., hexanal and (E)-2-hexenal] and compounds coming from amino acids (e.g., 2 and 3-methyl butanal). Both microsomes and deteriosomes were highly enriched in volatiles on a protein basis. The increase in volatile compounds in these fractions was influenced by fruit maturity and correlate closely with volatile development in the intact fruit. Volatiles may be generated in the microsomes and released from the membranes via deteriosomes.

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Hvitved-Jacobsen, T., K. Raunkjær y P. H. Nielsen. "Volatile fatty acids and sulfide in pressure mains". Water Science and Technology 31, n.º 7 (1 de abril de 1995): 169–79. http://dx.doi.org/10.2166/wst.1995.0226.

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The main objective was to study the anaerobic transformation of organic matter and sulfide production during wastewater transportation. Emphasis was on the transformation of easily biodegradable organic matter in terms of volatile fatty acids (VFA). Samples from two intercepting pressure mains located in the Northern part of Jutland, Denmark, were taken. The concentration of VFA in the wastewater varied considerably during day and night, being typically between 5 and 50 g/m3. A net production as well as a net removal of VFA was seen during transportation in the pressure mains probably depending on the quality and quantity of the organic matter. Typically 85% of the VFA was acetate and 10% propionate; the remainder was formate, n-butyrate and iso-butyrate. Observed sulfide production rates from the sewer biofilms were typically 0.05 and 0.005 g S/m2 h at 12 and 4 °C, respectively. A high sulfide production rate corresponded with a high VFA concentration. TOC removal was observed in the pressure mains.

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28

James, A. G., D. Hyliands y H. Johnston. "Generation of volatile fatty acids by axillary bacteria1". International Journal of Cosmetic Science 26, n.º 3 (junio de 2004): 149–56. http://dx.doi.org/10.1111/j.1467-2494.2004.00214.x.

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Reyhanitash, Ehsan, Bart Zaalberg, Sascha R. A. Kersten y Boelo Schuur. "Extraction of volatile fatty acids from fermented wastewater". Separation and Purification Technology 161 (marzo de 2016): 61–68. http://dx.doi.org/10.1016/j.seppur.2016.01.037.

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Yu, Jian y Kenneth L. Pinder. "Utilization of volatile fatty acids in methanogenic biofilms". Bioresource Technology 46, n.º 3 (enero de 1993): 241–50. http://dx.doi.org/10.1016/0960-8524(93)90127-w.

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Bhadra, Amit, Samuel Zelin, Jeno M. Schrer y Murray Moo-young. "Thermophilic bioconversion of cellulose to volatile fatty acids". Chemical Engineering Journal 33, n.º 1 (agosto de 1986): B19—B25. http://dx.doi.org/10.1016/0300-9467(86)80033-8.

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Patni, N. K. y P. Y. Jui. "Volatile fatty acids in stored dairy-cattle slurry". Agricultural Wastes 13, n.º 3 (enero de 1985): 159–78. http://dx.doi.org/10.1016/0141-4607(85)90031-9.

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M., Hasmadi, Nor Qhairul Izzreen M.N., A. H. Mansoor, M. H. A. Jahurul y M. K. Zainol. "Chemical compositions and volatile compounds of Sabah indigenous durian (Durio dulcis Becc.)". Food Research 5, n.º 2 (13 de febrero de 2021): 379–85. http://dx.doi.org/10.26656/fr.2017.5(2).545.

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The objective of this present work is to determine the chemical compositions and volatile compounds of Sabah indigenous durian (Durio dulcis Becc.). The results obtained showed that durian had 56.1% moisture, 3.5% protein, 2.8% fat, 1.4% ash, 36.26% carbohydrate, 6.6% dietary fiber and 7.0 µg of vitamin A. The mineral analysis results indicated that Durio dulcis is a good source of potassium, magnesium and phosphorus. Protein analysis found a total of sixteen major amino acids present in durian namely aspartame, serine, glutamin acid, glycine, histidine, arginine, threonine, alanine, proline, thyrosine, valine, methionine, lysine, isoleusine, leusine and phenylaline. A total of thirty-three individual fatty acids components were analysed. Among those, palmitic acid was a predominant saturated fatty acid while oleic acid was the most abundant unsaturated fatty acid. The composition of fatty acids showed that total of monounsaturated fatty acids, polyunsaturated fatty acids and saturated fatty acids were 56.7%, 6.7% and 36.6% respectively. A total of thirty-one volatile compounds were identified, among which alcohols, esters, sulphur-containing compounds and ketones were found to be the major constituents.

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Khrisanapant, Prit, Biniam Kebede, Sze Ying Leong y Indrawati Oey. "Effects of Hydrothermal Processing on Volatile and Fatty Acids Profile of Cowpeas (Vigna unguiculata), Chickpeas (Cicer arietinum) and Kidney Beans (Phaseolus vulgaris)". Molecules 27, n.º 23 (24 de noviembre de 2022): 8204. http://dx.doi.org/10.3390/molecules27238204.

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Legumes are an economical source of protein, starch, dietary fibre, fatty acids, vitamins and minerals. However, they are not as fully utilised, due to volatile compounds contributing to their undesirable odour. The purpose of this work was to understand the processing time’s effect on the legumes’ volatile profile. Hence, this study investigated the effects of hydrothermal processing times on the volatile and fatty acids profiles of cowpeas, chickpeas and kidney beans. All legumes were pre-soaked (16 h) and then hydrothermally processed at 95 °C for 15 to 120 min, using an open system to approximate standard household cooking practices and a closed system to represent industrial processing. Alcohol, aldehyde, acid and ester volatile compounds showed decreasing trends during processing, which can be associated with enzyme inactivation and process-induced degradation. This work showed that processing at 95 °C for 30 min significantly reduced the number of compounds commonly associated with undesirable odour, but showed no significant change in the fatty acid profile. Other volatiles, such as furanic compounds, pyrans and sulphur compounds, showed an increasing trend during processing, which can be related to the Maillard reactions. This observation contributes to the growing knowledge of legume processing and its impact on volatile flavour. It can advise consumers and the industry on selecting processing intensity to maximise legume utilisation.

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Katarína, Furdíková, Makyšová Katarína y Špánik Ivan. "Effect of indigenous S. cerevisiae strains on higher alcohols, volatile acids and esters in wine". Czech Journal of Food Sciences 35, No. 2 (29 de abril de 2017): 131–42. http://dx.doi.org/10.17221/79/2016-cjfs.

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Higher alcohols, volatile fatty acids, and esters are the most important volatiles and their formation is closely related to yeast strains employed during fermentation. In the present work, the effect of indigenous yeast strains on selected wine volatiles was examined using a highly sophisticated analytical method – comprehensive two-dimensional gas chromatography. Results of the statistical analysis revealed that each strain could be characterised and differentiated according to its volatile composition: strain Y2 was characterised by 2-phenylethanol and 1-hexanol, strain Y1 was in close relationship with high amounts of 4-methyl-1-pentanol, iso-amyl alcohol, ethyl 3-hydroxypentanoate and 3-methylpentanoic acid and strain Y3 was associated with 1-heptanol, cis-3-hexen-1-ol, β-phenylethyl butyrate, octanoic, and decanoic acids. The selection of an appropriate yeast strain thus represents a critical variable affecting the analysed volatile compounds (wine flavour) not only in a qualitative but also in a quantitative way.

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Legako, Jerrad F. "114 Effect of altering fatty acid profile on fresh meat palatability". Journal of Animal Science 97, Supplement_3 (diciembre de 2019): 108–9. http://dx.doi.org/10.1093/jas/skz258.223.

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Abstract Fatty acids in fresh meat contribute to palatability in many ways. However, fatty acids primarily influence flavor and juiciness. Perceived juiciness is impacted through lubrication by fatty acids and stimulation of saliva during mastication. Therefore, the content of fatty acids primarily impacts juiciness. However, for flavor, fatty acid content and composition are each important. Volatile flavor compounds have been demonstrated to have greater expression as overall fatty acid content increases. This may be through the retention of fat-soluble volatile compounds leading up to consumption. In addition to content, fatty acid composition may also be altered. Factors, such as, species, muscle, and diet dictate fatty acid composition. In general, these factors mediate proportions of major fatty acids and thus alter levels of fatty acid saturation. As fatty acid saturation is decreased, there is greater propensity towards oxidation. Greater fatty acid oxidation generally leads to negative off-flavors. During storage and handling there is opportunity for less saturated fresh meats to undergo oxidation, ultimately impacting flavor. To summarize, both fatty acid content and composition play roles in fresh meat palatability. Understanding the role of fatty acids in palatability helps equip processors and meat scientist to maintain or improve meat palatability.

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Bangerth, Fritz K., Jun Song y Josef Streif. "Physiological Impacts of Fruit Ripening and Storage Conditions on Aroma Volatile Formation in Apple and Strawberry Fruit: A Review". HortScience 47, n.º 1 (enero de 2012): 4–10. http://dx.doi.org/10.21273/hortsci.47.1.4.

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After a brief description of the “history of research” of aroma volatiles of apple and strawberry fruit, possible reasons for the reduced production of these important quality attributes by particular pre- and postharvest procedures are given. Among the possible physiological factors in association with reduced aroma volatile production, a reduced ethylene sensitivity, a decline in the rate of respiration as well as the content of adenine nucleotides and limited free fatty acids as precursors for aroma volatiles biosynthesis are proposed. A hypothesis about how this sequence of events leads to reduced volatile production is given and finally some suggestions of how to improve volatile synthesis are discussed.

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Dijkstra, J., J. France, H. D. St C. Neal, A. G. Assis, L. J. M. Aroeira y O. F. Campos. "Simulation of digestion in cattle fed sugarcane: model development". Journal of Agricultural Science 127, n.º 2 (septiembre de 1996): 231–46. http://dx.doi.org/10.1017/s0021859600078011.

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SUMMARYA dynamic model of digestion and absorption of nutrients in cattle fed sugarcane-based diets is described. There are 11 rumen state variables, and four zero pools representing absorbed nutrients. The rumen state variables represent nitrogen, carbohydrate, long chain fatty acid, microbial and volatile fatty acid pools. The zero pools relate to absorbed amino acids, glucose, long chain fatty acids, and volatile fatty acids. The flux equations are described by mass-action and Michaelis-Menten forms. Wherever possible, data derived from trials with cattle fed sugarcane-based diets were used to parameterize the model. Sensitivity analyses revealed that stability and behaviour of the model was generally satisfactory. The model was most sensitive to changes in fractional passage and substratehydrolysis rates and to the microbial maintenance requirement. Within the limited information available for comparison, the simulations agreed with observations of fibre flows and ammonia and volatile fatty acid concentrations in rumen fluid. Duodenal non-ammonia nitrogen flow was consistently underpredicted and reasons for this underprediction are suggested.

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Ye, Yangfan, Graham T. Eyres, Mariza G. Reis, Nicola M. Schreurs, Patrick Silcock, Michael P. Agnew, Patricia L. Johnson, Paul Maclean y Carolina E. Realini. "Fatty Acid Composition and Volatile Profile of M. longissimus thoracis from Commercial Lambs Reared in Different Forage Systems". Foods 9, n.º 12 (17 de diciembre de 2020): 1885. http://dx.doi.org/10.3390/foods9121885.

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Animal production factors can affect the fatty acid and volatile profile of lamb meat. The fatty acid and volatile composition of the M. longissimus thoracis was evaluated from 150 lambs from 10 groups of commercial lambs that differed in age, sex, diet and breed, from three farms, which represent typical forage lamb production systems in New Zealand. The meat from 4-month-old composite lambs slaughtered at weaning had a similar polyunsaturated to saturated fatty acid ratio compared to 6- to 8-month-old composite lambs, but a greater ratio than that of 12-month-old Merino lambs (p < 0.05), with all ratios being lower than the recommended ≥0.45. All lamb production systems produced meat with an omega-6 to omega-3 ratio below 1.5, well below the recommended ratio ≤ 4.0. Meat from 4-month-old lambs had higher C12:0, C14:0 and C16:0 and lower C18:0, reflecting the composition of the milk diet, resulting in higher atherogenic index than meat from other animal groups, while meat from 12-month-old Merino lambs, with lower content of polyunsaturated fatty acids, showed higher thrombogenic index. Meat from lambs processed at weaning contained the greatest concentration of eicosapentaenoic and docosahexaenoic acids, which would qualify as a ‘source’ or ‘good source’ of these target fatty acids based on the Commission of Regulation of the European Union or the Food Standards Australia New Zealand guidelines, respectively. Volatiles were extracted from the headspace of raw lean meat and 36 volatile compounds were identified. The abundance of carbon disulphide, isododecane, heptanal, 2,5-hexanediol and 3-octanone and pentanoic, octanoic, nonanoic and heptanoic acids was similar between all groups of lambs. Meat from 12-month-old Merino lambs had low abundance of acetic, propanoic, butanoic and hexanoic acids, and hexanal, octanal and dimethyl sulphide. For 6- to 8-month-old composite lambs, hexanal, octanal and nonanal were present at higher relative abundance in meat from lambs that grazed on chicory than perennial ryegrass. The significant differences in the fatty acid and volatile profiles in meat from 12-month-old Merino lambs compared with lambs slaughtered at weaning or further grazed on red clover, chicory or mixed pasture may result in distinctive nutritional value and lamb flavour.

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Pitman, A. R., L. H. Lötter, W. V. Alexander y S. L. Deacon. "Fermentation of Raw Sludge and Elutriation of Resultant Fatty Acids to Promote Excess Biological Phosphorus Removal". Water Science and Technology 25, n.º 4-5 (1 de febrero de 1992): 185–94. http://dx.doi.org/10.2166/wst.1992.0494.

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Research in South Africa has highlighted the dependence of biological phosphate removal mechanisms on the presence of certain minimum concentrations of some readily biodegradable materials including interalia volatile fatty acids. Generation of these compounds was achieved on an experimental basis at the Johannesburg Northern Works by the fermentation of primary sludge either in primary settling tanks or off-line in high rate “acid” digesters. Elutriation of the volatile fatty acids from the sludge was achieved by recycling the sludge to the influent sewage stream. Significant improvements in phosphate removal were observed and it was decided to design primary sludge treatment facilities to specifically generate the volatile fatty acids. This paper describes the design philosophy adopted and discusses the preliminary results obtained from the recently commissioned plant at the Johannesburg Northern Works and Bushkoppie plants.

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Rocha, Marisa A. A., Sona Raeissi, Patrick Hage, Wilko M. A. Weggemans, Jaap van Spronsen, Cor J. Peters y Maaike C. Kroon. "Recovery of volatile fatty acids from water using medium-chain fatty acids and a cosolvent". Chemical Engineering Science 165 (junio de 2017): 74–80. http://dx.doi.org/10.1016/j.ces.2017.02.014.

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Chen, Jia, Ruipeng Nan, Rufu Wang, Lixin Zhang y Junfeng Shi. "Ester-Producing Mechanism of Ethanol O-acyltransferaseEHT1Gene inPichia pastorisfrom Shanxi Aged Vinegar". BioMed Research International 2019 (3 de enero de 2019): 1–9. http://dx.doi.org/10.1155/2019/4862647.

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The ethanol O-acyltransferaseEHT1is an important element of key signaling pathways and is widely expressed in yeast strains. In this study, we investigated the expression ofEHT1 in the overexpression lines or knockout system ofPichia pastorisusing qRT-PCR and western blotting. The amount of total protein was determined using the Bradford method; the esterase activity was determined using p-nitrophenyl acetate as a substrate, and the production of volatile fatty acids in wild-type, knockout, and over-expression systems was detected using SPME GC-MS. The esterase activity ofEHT1-knockoutP. pastoriswas significantly lower than that in wild type (P<0.01), and the activities of esterase in threeEHT1-overexpressing strains—OE-1, OE-2, and OE-3—were significantly higher than those in wild type (P<0.01). In theEHT1-knockout strain products, the contents of nine volatile fatty acids were significantly lower than those in wild type (P<0.01), and the relative percentages of three fatty acids, methyl nonanoate, methyl decanoate, and ethyl caprate, were significantly lower than those in the other six species in the wild-type and knockout groups (P<0.05). The nine volatile fatty acids in the fermentation products of the overexpressedEHT1 gene were significantly higher than those in the wild-type group (P<0.01). The relative percentages of the three fatty acid esters, methyl nonanoate, methyl caprate, and ethyl caprate, were significantly higher than those in the other six species (P<0.05).EHT1 plays an important regulatory role in esterase activity and the production of medium-chain volatile fatty acids.

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Dopieralska, Patrycja, Joanna Barłowska, Anna Teter, Jolanta Król, Aneta Brodziak y Piotr Domaradzki. "Changes in Fatty Acid and Volatile Compound Profiles during Storage of Smoked Cheese Made from the Milk of Native Polish Cow Breeds Raised in the Low Beskids". Animals 10, n.º 11 (12 de noviembre de 2020): 2103. http://dx.doi.org/10.3390/ani10112103.

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This study investigated changes in the proximate chemical composition and profiles of fatty acids and volatile compounds of 12 smoked cheeses made from the milk of native Polish cow breeds used in Beskid Niski. Analyses were performed during the shelf life i.e., in the 1st, 21st, 42nd and 69th day of storage. Studies have shown that thanks to smoking and vacuum-packing, the chemical composition of cheese remained stable throughout the whole shelf-life. Up until the 21st day of storage, there were no statistically significant changes in the profile of fatty acids as well as volatile compounds. Changes were observed only after the mentioned storage time. After 21 days, there was a significant (p < 0.05) and steady decrease (up to day 69) in the proportion of odd-chain (by about 36%), branched-chain (by about 17%) and unsaturated fatty acids (by slightly over 1%). Among unsaturated fatty acids (p < 0.05), however, there was a significant increase in the proportion of monounsaturated fatty acids (by 5%) and a decrease in polyunsaturated fatty acids of nearly 12%. Storage lowered (by 47% in the 69th day of storage) the content of the conjugated linoleic acids (CLA), as well as lowered the n6 to n3 fatty acids ratio. During the 69 days of storage, the content of carboxylic acids increased to more than 50%. In the period from the 42nd to 69th day of cheese storage, the content of butyric acid and hexanoic acids increased twofold, whereas that of octanoic acid increased more than tenfold. Fifty-four volatile compounds were identified in the cheese. The largest group was ketones (34%), whose level decreased during storage, with 2-butanone, 3-hydroxy- (acetoin) and 2-butanone predominating. The research found that due to their low odor threshold, carboxylic acids may have negatively affected the flavor profile of the cheese.

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Salsali, H. R., W. J. Parker y S. A. Sattar. "Impact of concentration, temperature, and pH on inactivation of Salmonella spp. by volatile fatty acids in anaerobic digestion". Canadian Journal of Microbiology 52, n.º 4 (1 de abril de 2006): 279–86. http://dx.doi.org/10.1139/w05-125.

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It is known that the presence of volatile fatty acids may play a role in the inactivation of pathogens for systems that employ an acid phase reactor. This study was conducted to investigate the influence of volatile fatty acids on the inactivation of Salmonella spp. over a range of digestion temperatures. In this study, digesters that were treating municipal wastewater treatment plant sludges were operated at temperatures that ranged from 35 to 49 °C and had a solids residence time of 15 days. Samples collected from the effluent of the digesters were dosed with solutions containing acetic, propionic, and butyric acids alone and in mixtures, and the dosed effluents were analyzed for Salmonella spp. over time. In the first round of testing, the digester effluents were dosed with individual organic acids and also a mixture containing all three volatile fatty acids over a range of concentrations from 750 to 6000 mg/L, and the pH of the samples was fixed at a value of 5.5. In the second round of testing, the sample sludges were spiked with a fixed amount of organic acid mixture, and the pH was varied from 4.5 to 7.5. The reduction of Salmonella spp. in digester effluents, when dosed with volatile organic acids, was found to depend on pH, temperature, the chain length of the acids, and the concentration and composition of the acids present. Increases in temperature appeared to increase the inhibitory effects of the volatile organic acids. At mesophilic temperatures, acidic pHs resulted in a greater inhibition of Salmonella spp.; whereas at higher temperatures neutral pHs were found to be more inhibitory. The results suggest that acid phase digesters that operate at elevated temperatures and low pH can achieve substantial reduction of Salmonella spp.Key words: anaerobic digestion, decay kinetics, mesophilic, Salmonella spp., volatile organic acids.

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Zagklis, Dimitris, Marina Papadionysiou, Konstantina Tsigkou, Panagiota Tsafrakidou, Constantina Zafiri y Michael Kornaros. "Effect of pH on the Economic Potential of Dark Fermentation Products from Used Disposable Nappies and Expired Food Products". Applied Sciences 11, n.º 9 (30 de abril de 2021): 4099. http://dx.doi.org/10.3390/app11094099.

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Used disposable nappies constitute a waste stream that has no established treatment method. The purpose of this study was the assessment of the dark fermentation of used disposable nappies and expired food products under different pH values. The biodegradable part of the used disposable nappies was recovered and co-fermented with expired food products originating from supermarkets. The recoverable economic potential of the process was examined for different volatile fatty acids exploitation schemes and process pH values. The process pH strongly affected the products, with optimum hydrogen production at pH 6 (4.05 NLH2/Lreactor), while the amount of produced volatile fatty acids was maximized at pH 7 (13.44 g/L). Hydrogen production was observed at pH as low as pH 4.5 (2.66 NLH2/Lreactor). The recoverable economic potential was maximized at two different pH values, with the first being pH 4.5 with minimum NaOH addition requirements (181, 138, and 296 EUR/ton VS of substrate for valorization of volatile fatty acids through microbial fuel cell, biodiesel production, and anaerobic digestion, respectively) and the second being pH 6, where the hydrogen production was maximized with the simultaneous production of high amounts of volatile fatty acids (191, 142, and 339 EUR/ton VS of substrate respectively).

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Genovese, Alessandro, Andrea Marrazzo, Lucia De Luca, Raffaele Romano, Nadia Manzo, Felicia Masucci, Antonio Di Francia y Raffaele Sacchi. "Volatile Organic Compound and Fatty Acid Profile of Milk from Cows and Buffaloes Fed Mycorrhizal or Nonmycorrhizal Ensiled Forage". Molecules 24, n.º 8 (24 de abril de 2019): 1616. http://dx.doi.org/10.3390/molecules24081616.

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Seed inoculation of forage crops by arbuscular mycorrhizal fungi (AMF) generally results in higher profitability, but also modifies the chemical composition of silage in terms of increased biomass, protein, and dry matter. Raw milk aroma is affected by the type of feed. This work investigated the influence of ensiled forage obtained by seed inoculation with AMF on the volatile fractions and fatty acid composition of milk. Two experiments were carried out: in the first, buffaloes were fed maize silage, and in the second, cows were fed sorghum silage. The volatile fractions of milk were quantified by headspace solid-phase micro-extraction (HS-SPME), combined with gas chromatography–mass spectrometry (GC-MS), and fatty acids by gas chromatography (GC). The ensiled forage obtained with AMF increased saturated fatty acids (SFAs), and decreased monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) in both experiments. The volatile fraction in milk samples obtained from bovines fed mycorrhizal ensiled forage showed an increase of free fatty acids and ketones, responsible for cheesy and fruity odors. Aldehydes, responsible for green and grassy notes, increased only in the milk from buffaloes fed ensiled maize. Our results suggest that inoculation of maize and sorghum seed with AMF, combined with a low rate of fertilizers, leads to ensiled forage that could slightly affect the FA profile and odor quality of milk.

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Vasilica, Beldean (Tătar) Bianca, Maria Simona Chiș, Ersilia Alexa, Carmen Pop, Adriana Păucean, Simona Man, Marta Igual et al. "The Impact of Insect Flour on Sourdough Fermentation-Fatty Acids, Amino-Acids, Minerals and Volatile Profile". Insects 13, n.º 7 (24 de junio de 2022): 576. http://dx.doi.org/10.3390/insects13070576.

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Acheta domesticus (L.1758) has been recently accepted by the European Union as a novel food, being the third insect that has been approved for human consumption. Nowadays, researchers’ attention is focused on exploiting new protein sustainable sources, and, therefore, insect flour has gained more and more interest. Organic acids, fatty acids, amino acids, aroma volatile compounds, and minerals were analyzed through HPLC-RID (High-performance liquid chromatography), GC-MS (Gas chromatography-mass spectrometry), LC-MS (Liquid chromatography–mass spectrometry), ITEX/GC-MS and AAS (Atomic Absorption Spectrophotometry), respectively. Fermentation of the insect flour with Lactobacillus plantarum ATCC 8014 strain (Lp) leads to an increase in organic acids such as lactic, acetic, and oxalic, whilst citric acid decreases its value. SFA (saturated fatty acids) and MUFA (monosaturated fatty acids) groups were positively influenced by Lp fermentation; meanwhile, PUFA (polysaturated fatty acids) decreased during fermentation. A positive trend was observed for amino acids, aroma volatile content, and minerals enhancement during insect sourdough fermentation, mainly at 24 h of fermentation. Acheta domesticus (A. domesticus) sourdough fermentation represents a new tool that needs to be further exploited aiming to improve the nutritional qualities of the final products.

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Jung, Jong-Min, Jinwoo Cho, Ki-Hyun Kim y Eilhann E. Kwon. "Pseudo catalytic transformation of volatile fatty acids into fatty acid methyl esters". Bioresource Technology 203 (marzo de 2016): 26–31. http://dx.doi.org/10.1016/j.biortech.2015.12.048.

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Varel, V. H. y D. N. Miller. "Effect of carvacrol and thymol on odor emissions from livestock wastes". Water Science and Technology 44, n.º 9 (1 de noviembre de 2001): 143–48. http://dx.doi.org/10.2166/wst.2001.0526.

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A majority of the beef cattle and swine in the United States is produced in confined facilities. This generates significant environmental pollutants from the waste produced, including global warming gases, odor, and pathogens. The objectives of this study were to control the fermentation activity and pathogens in cattle and swine wastes with antimicrobial plant essential oils. Anaerobic one litre flasks with a working volume of 0.5 l were used to evaluate the effect of carvacrol and thymol on production of fermentation gas, short-chain volatile fatty acids, lactate, and bacterial populations. In cattle waste, 1 g l−1 each of carvacrol and thymol completely inhibited the production of volatile fatty acids and lactate over 23 days. In swine waste, 2.5 g l−1 carvacrol inhibited the production of all volatile fatty acids. We conclude that these essential oils are effective in controlling livestock waste odor emissions and field studies are warranted.

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50

de, Rosa, Carmine Iodice, Jordan Nechev, Kamen Stefanov y Simeon Popov. "Composition of the lipophilic extract from the sponge Suberites domuncula". Journal of the Serbian Chemical Society 68, n.º 4-5 (2003): 249–56. http://dx.doi.org/10.2298/jsc0305249d.

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The composition of the lipophylic extract from the sponge Suberites domuncula was investigated. Lipids and their fatty acids, as well as volatile compounds and sterols were identified. Stanols are the main class of steroids in the investigated sponge. A high concentration of unsaturated long chain fatty acids (C26?C28) was identified. The presence of branched and odd fatty acids indicates associated bacteria in the sponge.

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