Добірка наукової літератури з теми "Solid triacylglycerol content"

De novolipogenesis is the biological process by which C2precursors of acetyl-CoA are synthesized into fatty acids. In human subjects consuming diets higher in fat (>30 % energy), lipogenesis is down regulated and extremely low; typically < 10 % of the fatty acids secreted by the liver. This percentage will increase when dietary fat is reduced and replaced by carbohydrate, although the extent of carbohydrate-induced lipogenesis is dependent on the type of carbohydrate (monosaccharidev. polysaccharide) and the form in which the carbohydrate is fed (liquid meals, solid less-processed food). Clearly, massive overconsumption of carbohydrate can also increase lipogenesis. A second related phenomenon that occurs when dietary fat is reduced is hypertriacylglycerolaemia. This rise in blood triacylglycerol concentration could be due to increasedde novolipogenesis or to reduced clearance of lipid from the blood. The present paper will review the metabolic mechanisms leading to the elevations in blood triacylglycerol concentration that occur with dietary fat reduction. Studies considered will be those investigating fatty acid synthesis in subjects chronically fed low-fat high-carbohydrate diets and studies in which data were obtained in both the fasted and fed states. Also summarized will be data from subjects who had consumed diets of different carbohydrate types, as well as the most recent data from postprandial studies investigating factors that affect the magnitude of the rise in blood lipids following a meal. Given the changing availability of carbohydrate in the food supply, it will be important to understand how the balance of fat and carbohydrate in the diet influences lipogenesis, and the relative contribution of the process ofde novolipogenesis to the escalating incidence of obesity observed around the world.

We developed an alternative whipping cream fat using shea butter but with low saturation. Enriched stearic-oleic-stearic (SOS) solid fat was obtained from shea butter via solvent fractionation. Acyl migration reactant, which mainly contains asymmetric SSO triacylglycerol (TAG), was prepared through enzymatic acyl migration to obtain the creaming quality derived from the β’-crystal form. Through enzymatic acyl migration, we obtained a 3.4-fold higher content of saturated-saturated-unsaturated (SSU) TAG than saturated-unsaturated-saturated (SUS) TAG. The acyl migration reactant was refined to obtain refined acyl migration reactant (RAMR). An alternative fat product was prepared by blending RAMR and hydrogenated palm kernel oil (HPKO) at a ratio of 4:6 (w/w). The melting points, solid fat index (SFI), and melting curves of the alternative products were similar to those of commercial whipping cream fat. The alternative fat had a content of total unsaturated fatty acids 20% higher than that of HPKO. The atherogenic index (AI) of alternative fat was 3.61, much lower than those of whipping cream fat (14.59) and HPKO (1220.3), because of its low atherogenic fatty acid content and high total unsaturated fatty acids. The polymorphic crystal form determined by X-ray diffraction spectroscopy showed that the β’-crystal form was predominant. Therefore, the alternative fat is comparable with whipping cream that requires creaming quality, and has a reduced saturated fat content.

Fats that are rich in palmitic or stearic acids can be interesterified to increase their applicability for the production of certain foods. When compared with palmitic acid, stearic acid lowers low-density lipoprotein (LDL)-cholesterol, which is a well-known risk factor for coronary heart disease (CHD), but its effects on other cardiometabolic risk markers have been studied less extensively. In addition, the positional distribution of these two fatty acids within the triacylglycerol molecule may affect their metabolic effects. The objective was to compare the longer-term and postprandial effects of (interesterified) fats that are rich in either palmitic or stearic acids on cardiometabolic risk markers in humans. Two searches in PubMed/Medline, Embase (OVID) and Cochrane Library were performed; one to identify articles that studied effects of the position of palmitic or stearic acids within the triacylglycerol molecule and one to identify articles that compared side-by-side effects of palmitic acid with those of stearic acid. The interesterification of palmitic or stearic acid-rich fats does not seem to affect fasting serum lipids and (apo) lipoproteins. However, substituting palmitic acid with stearic acid lowers LDL-cholesterol concentrations. Postprandial lipemia is attenuated if the solid fat content of a fat blend at body temperature is increased. How (the interesterification of) palmitic or stearic acid-rich fats affects other cardiometabolic risk markers needs further investigation.

Vegetable oil is extracted from oil rich seeds, such as soybeans. Genetic engineering of green plants to accumulate oil in vegetative tissue is a future source of oil that promises increased land productivity and the use of marginal lands. However, the low concentration of lipids in current engineered plant biomass samples makes the oil extraction process challenging and expensive. In this study, liquid hot water (LHW) pretreatment was investigated to enhance oil recovery from the solids and increase enzymatic hydrolysis efficiency of such feedstocks. Corn germ meal was chosen as a model feedstock representing lipid-producing energy crops. Germ meal was pretreated at 160 and 180 °C for 10 and 15 min at 20% w/w solids loading. Enzymatic hydrolysis on the pretreated solid was performed. After pretreatment, the oil concentration increased by 2.2 to 4.2 fold. The most severe pretreatment condition of LHW, at 180 °C for 15 min, gave the maximum oil concentration (9.7%, w/w), the highest triacylglycerol (TAG) content of the extracted oil (71.6%), and the highest conversions of glucose and xylose (99.0% and 32.8%, respectively). This study demonstrates that the optimal pretreatment condition for corn germ meal is 180 °C LHW for 15 min. Pretreatment improves lipids recovery from oil bearing biomass with little or no effect on the lipid profile.

Physico-chemical properties of dietary fibres might be involved in metabolic control, particularly of the postprandial blood glucose response. The aim of the present study was to look at the effects of the content of soluble fibres and of the particle size of solid fibres onin vitroandin vivostarch hydrolysis and on the subsequent glucose absorption as well as the triacylglycerolaemia. Two sources of dietary fibres, one, with soluble fibres (beet pulp), the other with mostly insoluble fibres (wheat bran), were added at the rate of 60 g/kg to a meal simulating human food. The fibre sources were ground in order to obtain two different particle sizes (250 and 500 μm). Beet pulp decreased significantly (P< 0·05) initialin vitrohydrolysis whereas wheat bran increased starch hydrolysis in the first 10 min. Wheat bran and beet pulp, whatever its particle size, lowered the post-prandial triacylglycerol response. No significant effect was found with dietary fibre-supplemented diets on postprandial glycaemic and insulinaemic values. High correlation was found between initialin vitrostarch hydrolysis and mean areas under the insulinaemic curves. Thisin vitromodel can be used to predict initialin vivodigestion of carbohydrates from complex foods.

Only a few studies have been published on the postprandial effects of different fatty acids in obese subjects. Therefore, the present study investigated the effects of three test meals containing palm oil (PO), lard (LD), or puff-pastry margarine (PPM), all normal dietary ingredients, on postprandial lipid and hormone responses in normal-weight and obese young women. The study was performed as a randomized, crossover design. The fats differed in the content of palmitic acid, stearic acid, andtransmonounsaturated fatty acids allowing a dietary comparison of different ‘solid’ fatty acids. The obese women had significantly higher fasting concentrations and postprandial responses of plasma total triacylglycerol (TAG), chylomicron-TAG, and insulin compared with the normal-weight women but there was no significant difference in the postprandial responses between the three test meals. The obese women had fasting concentrations of leptin four times greater than the normal-weight women. There were no postprandial changes in the concentrations of leptin. The fasting concentrations of HDL-cholesterol were significantly lower in the obese women than in the normal-weight women, whereas there was no significant difference between the two groups in the concentrations of total cholesterol or LDL-cholesterol. These results provide evidence that obese women have exaggerated lipid and hormone responses compared with normal-weight women but the different contents of saturated andtransmonounsaturated fatty acids provided by PO, LD, and PPM have no effect in either group.

<p>The use of virgin red palm oil (VRPO) as a food product is very useful because it used as a source of fat and bioactive compounds (carotene, tocopherol, and tocotrienol). Increasing the use of VRPO can be conducted by blending it with lauric oils (coconut oil and palm kernel oil) containing medium-chain triacylglycerol (MCT) to produce a healthy oil. This research was conducted to examine the physicochemical properties of VRPO with coconut oil (CNO) or palm kernel oil (PKO) blends at a weight ratio of 100:0 - 0:100. The results showed that the mixtures of VRPO with CNO or PKO influenced the free fatty acid content, carotene content, fatty acids composition, iodine value, melting point, and solid fat content. Enhancing the amount of CNO or PKO onto VRPO causes the blends to have eutectic behavior (easy to melt). The VRPO: CNO and VRPO: PKO blends, at the ratio of 20:80 and 30:70, respectively, can be used as cooking oil. The VRPO: CNO blends at the ratio of 99:1 – 95:5 can be used for baking shortening while the VRPO: PKO blend at the ratio of 70:30 can be used for table margarine.</p><p align="center"><strong>ABSTRAK</strong></p><p>Penggunaan minyak sawit merah murni (<em>virgin red palm oil, </em>VRPO) sebagai produk pangan sangat bermanfaat karena VRPO sebagai sumber lemak dan senyawa bioaktif (karoten, tokoferol dan tokotrienol). Peningkatan pemanfaatan VRPO dapat dilakukan dengan memadukannya dengan minyak laurat (minyak kelapa dan minyak inti sawit) yang mengandung <em>medium chain triacylglycerol </em>(MCT) untuk menghasilkan campuran minyak sehat. Penelitian ini dilakukan untuk mengkaji sifat fisikokimia campuran minyak dari VRPO dengan minyak kelapa (<em>coconut oil, </em>CNO) atau minyak inti sawit (<em>palm kernel oil, </em>PKO) pada rasio berat 100:0 - 0:100. Hasil penelitian menunjukkan bahwa campuran minyak dari VRPO dengan CNO atau PKO mempengaruhi kadar asam lemak bebas, kadar karoten, komposisi asam lemak, bilangan iodin, titik leleh dan kandungan lemak padat. Peningkatan jumlah CNO atau PKO ke dalam VRPO menyebabkan campuran memiliki perilaku eutektik (mudah mencair). Campuran VRPO dengan CNO dan VRPO dengan PKO, masing-masing pada rasio 20:80 dan 30:70 dapat digunakan sebagai minyak goreng. Campuran VRPO dengan CNO pada rasio 99:1 - 95:5 dapat digunakan sebagai produk shortening untuk roti sementara campuran VRPO dengan PKO pada rasio 70:30 dapat digunakan untuk margarin meja.</p>

The majority of research has focused on the association betweentransunsaturated fatty acids (TUFA) from hydrogenated vegetable oils and heart disease even though TUFA are also produced from hydrogenated fish oil. We compared the acute effect of three solid fats on postprandial cholesterol, triacylglycerol (TAG) and NEFA concentrations in normocholesterolaemic males. Eight healthy male volunteers consumed each of the three 40g fat meals (partially hydrogenated fish oil (PHFO), palm oil and lard) in random order and blood samples were drawn at 2, 4, 6 and 8h thereafter for lipid analysis. The postprandial response in plasma TAG, TAG-rich lipoprotein-TAG (TRL-TAG), total cholesterol and plasma NEFA, measured as the area under the postprandial curve, was not significantly different between the three meals (p>0·05), which varied in MUFA, PUFA and TUFA content. There was no marked elevation of longer-chain fatty acids (C20–22,cisortransisomers) into the TRL-TAG fraction following the PHFO meal even though they provided 40% of the total fatty acids in the PHFO meal. The postprandial TRL-TAG response to PHFO was expected to be higher, as it is higher in TUFA, lower in PUFA and similar in saturated fatty acid composition compared with the lard and palm oil test meals. The absence of a higher postprandial response following ingestion of PHFO could be as a result of reduced absorption and increased oxidation of long-chain fatty acids (bothcisandtransisomers)

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.18.06 – технологія жирів, ефірних масел і парфумерно-косметичних продуктів. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2018. Дисертаційну роботу присвячено науковому обґрунтуванню перспективної технології одержання жирових продуктів з наперед заданими властивостями. Визначено триацилгліцерольний склад найбільш поширеної жирової сировини. Показано, що при загальній кількості триацилгліцеролів від 11 до 20 у кожному компоненті визначальними (за вмістом) є 7 – 10 триацилгліцеролів, від яких і залежать фізико-хімічні властивості жирових сумішей. На діаграмах диференційної скануючої калориметрії проаналізовані фазові перетворення для процесів плавлення та кристалізації в широкому діапазоні температур для одинадцяти сумішей. Виконано порівняльний аналіз температури в характерних точках з температурами плавлення і застигання. В результаті проведених обчислень знайдені коефіцієнти апроксимації для обчислення вмісту твердих триацилгліцеролів в характерних точках на діаграмі диференційної скануючої калориметрії і отриманих за допомогою ядерного магнітного резонансу, що дозволяє зіставляти і перераховувати результати обох аналізів, а це, в свою чергу, дозволяє досягати більш достовірних результатів. За допомогою плану Шеффе отримані рівняння регресії на базі яких розраховано рівняння залежності фізико-хімічних властивостей від триацилгліцерольного складу, що підтверджує можливість створення жирових основ жировмісних продуктів за допомогою відомого триацилгліцерольного складу. Розроблена методологія дозволяє скорегувати рецептуру жирових сумішей згідно із заданими фізико-хімічними властивостями або відтворювати вже існуючі рецептури за допомогою іншої сировини, на стадії лабораторних досліджень, ще до початку технологічного процесу і мінімізувати втрати енергоресурсів та час роботи лабораторії.
Thesis for a candidate Degree in Technical sciences, specialty 05.18.06 – technology of fats, essential oils and perfumery and cosmetic products. – National Technical University "Kharkiv Polytechnic Institute", of Ministry of Education and Science of Ukraine Kharkiv, 2018. The thiacylglycerol composition of the most common fatty material is determined. It is shown that in the total number of triacylglycerols from 11 to 20 in each component, the determinant (in content) is 7-10 triacylglycerols, on which the physical and chemical properties of fatty mixtures depend. In the diagrams of differential scanning calorimetry, phase transformations for melting and crystallization processes in a wide temperature range for eleven mixtures are analyzed. A comparative analysis of temperature at characteristic points with melting and freezing temperatures has been performed. As a result of the calculations, the coefficients of approximation were calculated for the calculation of the content of solid triacylglycerols in the characteristic points on the differential scanning calorimetry diagram and obtained with the help of a nuclear magnetic resonance, which allows to compose and recalculate the results of both analyzes, which in turn allows us to achieve more reliable results. Using the Scheffe plan, regression equations were derived on the basis of which the equation of the dependence of physical and chemical properties on the triatsilglycerol composition was calculated, which confirms the possibility of creating fatty bases of fat-containing products with the help of knowledge of the triacylglycerol composition. The developed methodology allows to adjust the formula of fat mixtures according to the given physical and chemical properties or to reproduce already existing recipes with the help of other raw materials, at the stage of laboratory research, before the beginning of the technological process and to minimize energy losses and the time of the laboratory.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.18.06 – технологія жирів, ефірних масел і парфумерно-косметичних продуктів. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2018. Дисертаційну роботу присвячено науковому обґрунтуванню перспективної технології одержання жирових продуктів з наперед заданими властивостями. Визначено триацилгліцерольний склад найбільш поширеної жирової сировини. Показано, що при загальній кількості триацилгліцеролів від 11 до 20 у кожному компоненті визначальними (за вмістом) є 7 – 10 триацилгліцеролів, від яких і залежать фізико-хімічні властивості жирових сумішей. На діаграмах диференційної скануючої калориметрії проаналізовані фазові перетворення для процесів плавлення та кристалізації в широкому діапазоні температур для одинадцяти сумішей. Виконано порівняльний аналіз температури в характерних точках з температурами плавлення і застигання. В результаті проведених обчислень знайдені коефіцієнти апроксимації для обчислення вмісту твердих триацилгліцеролів в характерних точках на діаграмі диференційної скануючої калориметрії і отриманих за допомогою ядерного магнітного резонансу, що дозволяє зіставляти і перераховувати результати обох аналізів, а це, в свою чергу, дозволяє досягати більш достовірних результатів. За допомогою плану Шеффе отримані рівняння регресії на базі яких розраховано рівняння залежності фізико-хімічних властивостей від триацилгліцерольного складу, що підтверджує можливість створення жирових основ жировмісних продуктів за допомогою відомого триацилгліцерольного складу. Розроблена методологія дозволяє скорегувати рецептуру жирових сумішей згідно із заданими фізико-хімічними властивостями або відтворювати вже існуючі рецептури за допомогою іншої сировини, на стадії лабораторних досліджень, ще до початку технологічного процесу і мінімізувати втрати енергоресурсів та час роботи лабораторії.
Thesis for a candidate Degree in Technical sciences, specialty 05.18.06 – technology of fats, essential oils and perfumery and cosmetic products. – National Technical University "Kharkiv Polytechnic Institute", of Ministry of Education and Science of Ukraine Kharkiv, 2018. The thiacylglycerol composition of the most common fatty material is determined. It is shown that in the total number of triacylglycerols from 11 to 20 in each component, the determinant (in content) is 7-10 triacylglycerols, on which the physical and chemical properties of fatty mixtures depend. In the diagrams of differential scanning calorimetry, phase transformations for melting and crystallization processes in a wide temperature range for eleven mixtures are analyzed. A comparative analysis of temperature at characteristic points with melting and freezing temperatures has been performed. As a result of the calculations, the coefficients of approximation were calculated for the calculation of the content of solid triacylglycerols in the characteristic points on the differential scanning calorimetry diagram and obtained with the help of a nuclear magnetic resonance, which allows to compose and recalculate the results of both analyzes, which in turn allows us to achieve more reliable results. Using the Scheffe plan, regression equations were derived on the basis of which the equation of the dependence of physical and chemical properties on the triatsilglycerol composition was calculated, which confirms the possibility of creating fatty bases of fat-containing products with the help of knowledge of the triacylglycerol composition. The developed methodology allows to adjust the formula of fat mixtures according to the given physical and chemical properties or to reproduce already existing recipes with the help of other raw materials, at the stage of laboratory research, before the beginning of the technological process and to minimize energy losses and the time of the laboratory.