Academic literature on the topic 'Antioxident- edible oil preservation'

Different formulations of chitosan (1%, 2%, or 3%) with the incorporation of cinnamon oil (0.25% or 0.50%) were prepared for the preservation of pomegranate aril cv. Bhagwa. Six combinations of chitosan-cinnamon oil formulations along with one control (untreated) were applied to the freshly extracted arils using the dipping application method. All treatments were found to be effective in enhancing the shelf life, improving the postharvest characteristics, and reducing microbial populations on pomegranate arils during a 15-day storage period at 4 ± 1°C. The treated pomegranate arils exhibited excellent resistance to microbial decay, moisture loss, respiration rate, preservation of phenolics, flavonoids, and antioxidants activity, among other characteristics. Chitosan 2% + cinnamon oil 0.25% edible coating has a high potential to enhance the storage life and biochemical properties and reduce the microbial population of arils. This treatment recorded a higher total phenolic content (18%) and antioxidant activity (16%) than the control sample, respectively, at the end of storage. In addition, the treatment also helped to decrease the microbial activity by 45% compared to the control sample. The present investigation proposed an alternative method to prolong the shelf life of pomegranate arils during the 15 days of storage.

In this study, the effects of the application of edible coatings on the shelf life of the strawberry were evaluated, with the aim of extending the fruit’s availability and shelf life while preserving its qualitative characteristics. In particular, the application of edible coatings enriched with a natural antioxidant to strawberries was evaluated for their physicochemical, microbial, and structural properties, during a storage period (up to 14 days) at refrigerated temperature. The experimental plan provided the formulation for edible coatings enriched with different concentrations of a natural antioxidant extract obtained from bergamot (Citrus bergamia Risso) pomace (1, 2.5, and 5%), bergamot essential oil (0.1% v/v and 0.2% v/v), and a synthetic antioxidant, butylated hydroxytoluene (BHT, 100 ppm). Moreover, a control test with untreated strawberries was considered. The enriched gum Arabic coatings provided good results related to the preservation of the qualitative parameters of the strawberries. The samples coated with the antioxidant extract (2.5%, sample D) and bergamot essential oil (0.1%, sample F) showed the best maintenance of the qualitative parameters after 14 days, showing lower decay rates (36% D and 27% F), good acceptability by consumers (between 5 and 6), and good retention of ascorbic acid (>30 mg 100 g−1).

Medicinal plants contain various secondary metabolites. The present study analyzed the essential oil of buds from clove (Syzygium aromaticum L.; Family: Myrtaceae) using gas chromatography-mass spectrometry (GC-MS). GC-MS analysis showed the presence of six major phytoconstituents, such as eugenol (66.01%), caryophyllene (19.88%), caryophyllene oxide (5.80%), phenol, 2-methoxy-4-(2-propenyl)-acetate (4.55%), and humulene (3.75%). The effect of clove essential oils (CEO) at 0%, 1%, 2%, and 3% (w/w) on the mechanical and barrier properties of starch films was evaluated. The tensile strength (TS) and elongation (E) of films with clove essential oil were 6.25 ± 0.03 MPa and 5.67% ± 0.08%, respectively. The antioxidant activity of the films significantly increased the millet starch film and presented the lowest antioxidant activity (0.3%) at a 30 minute incubation for the control sample, while increasing CEO fraction in the starch film lead to an increase in antioxidant activity, and the 3% CEO combined film presented the highest antioxidant activity (15.96%) at 90 min incubation. This finding could be explained by the incorporation of clove oil containing antioxidant properties that significantly increased with the incorporation of CEO (p < 0.05). A zone of inhibition ranging from 16 to 27 mm in diameter was obtained when using a concentration of CEO ranging from 1% to 3%. We also observed the presence of an antimicrobial activity on several tested microorganism including Escherichia coli, Pseudomonas aeruginosa, Enterobacter sp, Bacillus cereus, Staphylococcus aureus, and Trichoderma fungi. Thus, the current study reveals the possibility of using a millet starch edible film as a preservation method.

Lipid oxidation is a major cause of off-flavors and the loss of nutrients in fat-containing foods and oils. The prevention or retardation of those deteriorative reactions of oil during processing and storage is required. Commercially available synthetic packaging materials are causing serious environmental problems due to their non-degradability. To reduce environmental impacts associated with synthetic plastics, biopolymer materials have a great potential to be used instead. Further, biopolymers play an important role in food preservation because of their antioxidant and antimicrobial activities. The packing system is comprised of natural active materials that can improve the shelf life of oil-packed, minimize oxidation and improve mechanical, barrier and biological properties of biopolymer films. This paper aims to review currently available literature in the field of biopolymer materials application for packaging different types of edible oils.

The mango is the most widely cultivated tropical fruit. Fresh-cut mango is very useful, but it is very perishable. The purpose of this study was to highlight the effects of neem oil on fresh-cut mango fruits kept for 9 days at 4 ± 1 °C and 80 ± 5% relative humidity. The neem plant (Azadirachta indica) has numerous antioxidant and antibacterial properties. Despite this, very few studies have been carried out on neem oil added to edible coatings (EC) to retard ripening processes. Two formulations were tested: EC1 (hydroxypropyl methylcellulose + CaCl2) and EC2 (hydroxypropyl methylcellulose + CaCl2 + neem oil), both compared with an untreated sample (control). Physicochemical, microbial, proximate and sensory analyses were carried out. Neem oil reduced loss of firmness and colour, while hydroxypropyl methylcellulose and CaCl2 reduced normal cell degradation (weight loss and soluble solids content). Microbiological investigation showed that the EC2 inhibited the development of the main spoilage bacteria during the entire storage period, prolonging the preservation of fresh-cut fruits. The sensory analysis showed a rapid degradation after 5 d in the control sample, while the EC2 was the best.

In this study, the addition of oregano oil chitosan nanoparticles (OEO-CSNPs) was conducted to enhance the comprehensive properties of gelatin films (GA), and the optimal addition ratio of nanoparticles was determined for its application in the preservation of mullet. Oregano oil chitosan nanoparticles were organically combined with gelatin at different concentrations (0%, 2%, 4%, 6% and 8%) to obtain oregano oil–chitosan nanoparticle–GA-based composite films (G/OEO-CSNPs), and thereafter G/OEO-CSNPs were characterized and investigated for their preservative effects on mullet. Subsequent analysis revealed that OEO-CSNPs were uniformly dispersed in the GA matrix, and that G/OEO-CSNPs had significantly improved mechanical ability, UV-visible light blocking performance and thermal stability. Furthermore, the nanoparticles exhibited excellent antioxidant and antibacterial properties, and they improved the films’ suitability as edible packaging. The attributes of the G/OEO-CSNPs were optimized, the films had the strongest radical scavenging and lowest water solubility, and electron microscopy also showed nanoparticle penetration into the polymer when the concentration of OEO-CSNPs was 6% (thickness = 0.092 ± 0.001, TS = 47.62 ± 0.37, E = 4.06 ± 0.17, water solubility = 48.00 ± 1.11). Furthermore, the GA-based composite film containing 6% OEO-CSNPs was able to inhibit microbial growth, slow fat decomposition and protein oxidation, reduce endogenous enzyme activity, and delay the spoilage of mullet during the refrigeration process, all of which indicate its excellent potential for meat preservation application.

Andean blackberry is cultivated in Colombia due to its national and international commercial importance, in addition to its flavour and high nutritional value. Due to its physicochemical, morphological, and physiological characteristics, it constitutes one of the most unstable fruits in the Colombian fruit and vegetable supply chain, thereby generating economic losses. In this study, a polymer-based coating of Aloe vera and essential oil was designed, and its influence on the shelf life of Andean blackberry stored at 4 °C was studied. Once the appropriate composition was established according to the experimental design, Andean blackberries’ physicochemical parameters, the content of total phenols, and antioxidant activity were monitored over 19 days. The total soluble solids present a change between 5.2 and 5.6° Brix and 5.2 and 7.2° Brix for coated and uncoated fruits between 1 and 19 days, respectively. The coated fruits presented a lower loss compared to the uncoated fruits and the total phenol content presented a higher concentration on day 19 in the coated fruits (412.71 ± 37.5 mg Gallic Acid Equivalents L−1 sample). The coating enabled an increase in the shelf life of the blackberries, from 4 to 19 days, while preserving the physicochemical properties of the fruits. Therefore, the application of coating as a method for the post-harvest preservation of Andean blackberries represents a low-cost, easily available strategy.

Reducing the negative effects of synthetic packaging on the environment and increasing consumer demands for the natural preservation of food has pioneered the search for alternative methods in this field. Edible films and coatings, one of the innovations in packaging technology, are used to extend the shelf life of foods and improve their quality by acting as a barrier against moisture, gas, oil, and flavor transmission. Different biopolymers such as protein, polysaccharides, and lipids are used in the production of edible films and coatings that are applied to the surface of foods as a thin layer or can be used as packaging material. In addition to these biopolymers, plasticizers, emulsifiers, antioxidants and antimicrobials can be used to improve the mechanical and functional properties of edible films and coatings. The method used to make the films, the type of coating material used, the type and concentration of plasticizer used, the drying process used during the film preparation stage, and environmental factors (temperature, relative humidity, pressure) all have an impact on the physical and mechanical properties of edible films or coatings. In this review article, the film materials used for edible films and coatings, film preparation methods, environmental and structural factors affecting the structure of the films were compiled together, and the effects of these factors on the quality properties of the films were evaluated. At the same time, the usage areas of edible films in food were also evaluated.

Edible coating is extensively applied for fresh produce preservation. In the present study, Aloe vera gel (AV) alone or combined with sage essential oil (EO; 0.1% or 0.5%) was used as fruit edible coating in tomatoes. Following treatments, tomatoes were stored at 11 °C and 90% relative humidity (RH) up to 14 days and analyzed for quality maintenance compared with uncoated fruits (control). Results showed that both AV and EO decreased decay symptoms with more pronounced effects on low EO concentration (i.e., 0.1%). The application of 10% of AV coating decreased fruit ethylene emission while EO (0.1% and 0.5%) application increased ethylene emission and respiration rates. AV coating decreased acidity, β-carotene, lycopene content and maintained fruit firmness. High levels of EO (0.5%) increased weight loss but decreased fruits’ redness, chroma, total soluble solids, acidity, β-carotene and lycopene content. Total phenolic content and antioxidants maintained or increased during storage when treated with AV and/or EO. Low levels of EO (0.1%) maintained or improved fruit quality characteristics during storage, and this was mirrored by the sensory evaluation preference (including the AV application) and quality related attributes.

The concept of this study is the replacement of previous fossil-based techniques for food packaging and food shelf-life extension, with novel more green processes and materials following the spirit of circular economy and the global trend for environmentally positive fingerprints. A novel adsorption process to produce thymol-halloysite nanohybrids is presented in this work. The high dispersion of this thymol-halloysite nanostructure in chitosan biopolymer is one of the goals of this study. The incorporation of this biodegradable matrix with poly-vinyl-alcohol produced a very promising food-packaging film. Mechanical, water-oxygen barrier, antimicrobial, and antioxidant properties were measured. Transparency levels were also tested using a UV-vis instrument. Moreover, the developed films were tested in-vivo for the preservation and the extension of the shelf-life of kiwi fruits. In all cases, results indicated that the increased fraction of thymol from thyme oil significantly enhances the antimicrobial and antioxidant activity of the prepared chitosan-poly-vinyl- alcohol gel. The use of the halloysite increases the mechanical and water-oxygen barrier properties and leads to a control release process of thymol which extends the preservation and the shelf-life of kiwi fruits. Finally, the results indicated that the halloysite improves the properties of the chitosan/poly-vinyl-alcohol films, and the thymol makes them further advantageous.

[ES] En esta Tesis, se han analizado diferentes estrategias para adaptar las formulaciones de almidón con el fin de obtener recubrimientos útiles en la conservación poscosecha de frutas. El almidón se sustituyó parcialmente por gomas de origen microbiano (xantano, gelano y pululano) para mejorar las propiedades funcionales de las películas. La adición de gelano a la matriz de almidón, redujo su capacidad de adsorción de agua y la permeabilidad al vapor de agua y oxígeno. Tuvo un efecto positivo en las propiedades mecánicas, mejorando su resistencia a la rotura y previniendo la retrogradación. La goma xantana aumentó la resistencia a la rotura de las películas de almidón, pero no redujo su capacidad de adsorción de agua y la permeabilidad al vapor de agua. La sustitución del almidón por un 10 o 20% de gelano, podría ser una buena estrategia para obtener películas con propiedades más adecuadas con fines de envasado/recubrimiento de alimentos. Se analizaron películas mezcla de almidón-gelano con aceite esencial de tomillo (EO), con el objetivo de proporcionar actividad antifúngica a las formulaciones. El aceite se incorporó mediante emulsificación directa o encapsulado en liposomas de lecitina. Las películas mostraron un efecto antifúngico en las pruebas in vitro contra A. alternata y B. cinerea. La encapsulación del EO promovió una mayor retención del aceite, mejorando su actividad antifúngica, siendo éstas más efectivas contra B. cinerea que contra A. alternata. Una mayor proporción de almidón en el film dio lugar a mayor crecimiento fúngico a baja concentración del compuesto activo. Todas las películas exhibieron alta capacidad de barrera al oxígeno. La lecitina mejoró la capacidad de barrera al vapor de agua y redujo la rigidez, la resistencia a la rotura y la extensibilidad. Las películas con EO encapsulado, con una proporción de almidón-gelano de 8:2, fueron las más efectivas para controlar el crecimiento fúngico. Para aplicar las formulaciones de almidón-gelano como recubrimientos, se analizaron las propiedades superficiales de distintas frutas (manzana, tomate y caqui), y el coeficiente extensibilidad de las formulaciones sobre la superficie de la frutas, en función de la concentración de Tween 85. Las pieles de las frutas evaluadas se comportaron como superficies de baja energía. La adición de Tween 85 a las muestras sin EO, tuvo un efecto positivo en el ángulo de contacto y la tensión superficial. Sin embargo, cuando contenían EO, emulsionado o encapsulado en lecitina, el surfactante ejerció un efecto negativo en estas propiedades, dependiendo de su concentración. Las formulaciones con EO, emulsionado o encapsulado, no requirieron surfactante para mejorar su extensibilidad, mientras que la adición de Tween 85 a una concentración de 5x104 mg/L, mejoró notablemente esta propiedad en formulaciones S:G sin EO. Recubrimientos a base de almidón-gelano, con o sin EO emulsionado o encapsulado en liposomas de lecitina, fueron aplicados en manzanas y caquis. Los recubrimientos no redujeron la pérdida de peso en las manzanas, pero evitaron la pérdida de agua en los caquis. No se observó un efecto significativo de los recubrimientos en las tasas de respiración y el cociente de respiración de los caquis, mientras que estos parámetros aumentaron en manzanas. En los ensayos in vivo, los recubrimientos sin lecitina redujeron la incidencia y severidad de la mancha negra por A. alternata en caquis, y la severidad del moho gris por B. cinerea en manzanas. A pesar de su acción antifúngica in vitro, el EO no ejerció un efecto antifúngico adicional en la fruta. Esto podría explicarse por las interacciones particulares entre los componentes del recubrimiento, la superficie de la fruta y el patógeno. Los recubrimientos a base de almidón-gelano sin lecitina ni EO podrían aplicarse en caquis para controlar la pérdida de peso y reducir la incidencia de A. alternata.
[CAT] En esta Tesi, s'han analitzat diferents estratègies per a adaptar les formulacions de midó a fi d'obtenir recobriments útils per a la conservació postcollita de fruites. El midó es va substituir parcialment per gomes d'origen microbià (xantano, gelano i pululano) per a millorar les propietats funcionals de les pel¿lícules. L'addició de gelano a les pel¿lícules de midó, va reduir la seua capacitat d'adsorció d'aigua. També va tindre un efecte positiu en les propietats mecàniques, i va millorar la seua resistència a la ruptura i va prevenir els fenòmens de retrogradació. La goma de xantano també va augmentar la resistència a la ruptura de les pel¿lícules de midó, però no va reduir la seua capacitat d'adsorció d'aigua i la permeabilitat al vapor d'aigua. La substitució del midó per un 10 o 20% de gelano, podria ser una bona estratègia per a obtenir pel¿lícules amb propietats més adequades per al envasat/recobriment d'aliments. S'analitzaren les pel¿lícules mescla de midó-gelano amb oli essencial de timó (EO), amb l'objectiu de proporcionar activitat antifúngica a les formulacions. L'oli es va incorporar mitjançant emulsificació directa o encapsulat en liposomes de lecitina. Estes pel¿lícules van mostrar un efecte antifúngic en les proves in vitro contra A. alternata i B. cinerea. L'encapsulació de l'EO en els liposomes de lecitina va promoure una major retenció de l'oli i va millorar la seua activitat antifúngica, sent estes més efectives contra B. cinerea que contra A. alternata. En les formulacions amb una major proporció de midó amb baix contingut en compost actiu va haver un major creixement fúngic. Totes les pel¿lícules van exhibir alta capacitat de barrera a l'oxigen. La presència de lecitina va millorar la capacitat de barrera al vapor d'aigua i va reduir la rigidesa, la resistència a la ruptura i l'extensibilitat. Les pel¿lícules amb EO encapsulat, amb una proporció de midó-gelano 8: 2, van ser les més efectives per a controlar el creixement fúngic. Amb l'objectiu d'aplicar les formulacions de midó-gelano com a recobriments, es van analitzar les propietats superficials de distintes fruites (poma, tomaca i caqui), i el coeficient d'extensibilitat d'estes formulacions sobre la superfície de la fruita, en funció de la concentració de Tween 85. Les pells de les fruites avaluades es van comportar com a superfícies de baixa energia. L'addició de Tween 85 a les formulacions sense EO, va tenir un efecte positiu en els angles de contacte i la tensió superficial. En presència de l'EO, emulsionat o encapsulat en liposomes de lecitina, el tensioactiu va exercir un efecte negatiu en estos valors, depenent de la seua concentració. Els recobriments amb EO, emulsionat o encapsulat, no van requerir tensioactiu per a millorar la seua extensibilitat, mentre que l'addició de Tween 85 a una concentració de 5x104 mg/L, va millorar notablement esta propietat en les formulacions sense EO. Recobriments a base de midó-gelano, amb o sense l'agregat d'EO emulsionat o encapsulat en liposomes, van ser aplicats en pomes i caquis.. Els recobriments no van reduir la pèrdua de pes en les pomes, però van evitar la pèrdua d'aigua en els caquis. No es va observar un efecte significatiu dels recobriments en les taxes de respiració i el quocient de respiració dels caquis, mentre que les taxes i el quocient de respiració van augmentar en les pomes. En els assajos in vivo, els recobriments sense lecitina van reduir la incidència i severitat de la taca negra per A. alternata en els caquis, i la severitat de la floridura grisa per B. cinerea en les pomes. No obstant això, la incorporació de l'EO no va exercir un efecte antifúngic addicional en la fruita. Açò podria explicar-se per les interaccions particulars entre els components del recobriment, la superfície de la fruita i el patogen. Els recobriments a base de midó-gelano sense lecitina o EO de timó podrien aplicar-se en caqui
[EN] In this Thesis, different strategies have been analysed to tailor starch formulations for the purposes of obtaining useful coatings in postharvest fruit preservation. Starch was partially substituted by microbial gums (xanthan, gellan, and pullulan) in order to improve film functional properties. Moisture sorption capacity and water vapour and oxygen permeability were reduced by the presence of gellan gum in the starch films. It also had a positive effect on the tensile properties, enhancing the films' strength and resistance to break and preventing retrogradation phenomena. Xanthan gum increased the tensile strength of the starch films, but did not reduce their water sorption capacity and water vapour permeability. Functional properties were not notably improved by the addition of pullulan. Then, 10 and 20 % starch could be substituted by gellan gum to obtain films with more adequate properties for food packaging/coating purposes. Starch-gellan blend films containing thyme essential oil (EO) were also studied in order to provide antifungal activity to the formulations. This was incorporated either by direct emulsification or encapsulated in lecithin liposomes. These films exhibited antifungal effect in in vitro tests against A. alternata and B. cinerea. The encapsulation of the EO in lecithin liposomes allowed for greater EO retention in the films, enhancing their antifungal activity, which were more effective against B. cinerea than against A. alternata. The antifungal action was slightly affected by the polymer matrix composition. Thus, the greatest starch ratio enhanced the fungal growth when the content of the active compound was low. All the films exhibited high oxygen barrier capacity. The presence of lecithin enhanced their water vapour barrier capacity and reduced the film stiffness, resistance to break and extensibility. The films with lecithin-encapsulated EO, with a starch-gellan ratio of 8:2, were the most effective at controlling fungal growth. In order to apply these starch-gellan formulations as fruit coatings, the surface properties of apple, tomato and persimmon, and the spreadability coefficient of these liquid formulations on the fruit surface, were analysed as a function of the concentration of Tween 85, as surfactant. The fruit skins behaved as low-energy surfaces. The values of the contact angles and surface tension of EO-free formulations were positively influenced by the addition of Tween 85. However, in the presence of emulsified or lecithin-encapsulated thyme EO, the surfactant exerted a negative effect, depending on its concentration. Coating-forming systems containing emulsified or encapsulated EO did not require surfactant to improve their already good spreadability, while Tween 85 at 5x104 mg/L notably improved this property in EO-free formulations. Starch-gellan coatings, containing or not emulsified or lecithin-encapsulated EO, were applied on apples and persimmons. Coatings did not reduce the weight loss in apples, but they prevented water loss in persimmons. In contrast, no significant effect of the coatings was observed on respiration rates and respiration quotient of persimmons, whereas they increased the respiration rates and quotient in apples. Coatings did not affect the changes in fruit firmness either in apples or persimmons. In the in vivo assays, the coatings without lecithin reduced the incidence and severity of black spot caused by A. alternata in persimmons, and the severity of grey mould caused by B. cinerea in apples. The incorporation of EO did not exert an additional antifungal effect on the fruit and seemed to exert a negative effect on some other fruit quality attributes. This could be explained by the particular interactions of the coating components, fruit surface and pathogen. Starch-gellan coatings without lecithin or thyme EO could be used in persimmons to control weight loss and reduce the incidence of infections caused by A. alternata.
This work has been founded by the “Ministerio de Economía y Competitividad” of Spain, through the Project AGL2016-76699-R and the “Conselleria de Educación, Investigación, Cultura y Deporte de la Generalitat Valenciana” trough the Santiago Grisolía grant GRISOLIA/2015/001.
Sapper, MI. (2019). Starch based coatings with thyme essential oil for fruit preservation [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/124342
TESIS

Fresh fruit has recently gained popularity in the market for healthy, organic, functional, and convenient foods. Production and consumption of fresh fruit increases from time to time. Consumer demand for fresh fruits that are rich in nutrition and health benefits have presented a challenge to the food industry to obtain appropriate technology to meet the need. However, there are some limitations regarding the storage of the fresh fruits. Fresh fruits cannot stand for a long term due to the rapid of ripening process in the fruit’s tissues. The ripening process commonly related to the respiration and transpiration process in the fruits tissue. Besides, the fresh-cut fruits also easily getting spoilage with a growth of microbial in the fruits. There are some innovations regarding packaging food film from synthetic materials which are quite wide applied in the food industry. This material is not an environmentally friendly due to the synthetic’s materials are not made by natural resources. Study towards the application of natural resources in the formation edible film packaging have been done. It is due to the global demand to replace the synthetic plastic film packaging with biodegradable film packaging that are environmentally friendly and users friendly. This review aims at providing a broad overview of recent scientific research related to preservation of fruits in the food industry and its health effects in consumers. It involved recent analysis of edible film incorporate with different type of essential oils from natural sources such as plants for preservations of fruits.