scholarly journals XII.—Studies on the oxidation of unsaturated fatty oils and unsaturated fatty acids. Part I. The formation of acrolein by the oxidation of linseed oil and linolenic acid

1916 ◽  
Vol 109 (0) ◽  
pp. 138-145 ◽  
Author(s):  
Arthur Henry Salway
2008 ◽  
Vol 15 (4) ◽  
pp. 402 ◽  
Author(s):  
M. NYKTER ◽  
H-R. KYMÄLÄINEN ◽  
F. GATES

In this review the quality properties of linseed oil for food uses are discussed as well as factors affecting this quality. Linseed oil has a favourable fatty acid composition with a high linolenic acid content. Linseed oil contains nearly 60% á-linolenic acid, compared with 25% for plant oils generally. The content of linolenic acid and omega-3 fatty acids is reported to be high in linseed grown in northern latitudes. The composition of fatty acids, especially unsaturated fatty acids, reported in different studies varies considerably for linseed oil. This variation depends mainly on differences in the examined varieties and industrial processing treatments. The fatty acid composition leads also to some problems, rancidity probably being the most challenging. Some information has been published concerning oxidation and taste, whereas only a few studies have focused on colour or microbiological quality. Rancidity negatively affects the taste and odour of the oil. There are available a few studies on effects of storage on composition of linseed oil. In general, storage and heat promote auto-oxidation of fats, as well as decrease the amounts of tocopherols and vitamin E in linseed oil. Several methods are available to promote the quality of the oil, including agronomic methods and methods of breeding as well as chemical, biotechnological and microbiological methods. Time of harvesting and weather conditions affect the quality and yield of the oil.;


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lihong Ma ◽  
Xinqi Cheng ◽  
Chuan Wang ◽  
Xinyu Zhang ◽  
Fei Xue ◽  
...  

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.


1944 ◽  
Vol 22f (6) ◽  
pp. 191-198 ◽  
Author(s):  
H. W. Lemon

Linseed oil that has been hydrogenated to a plastic consistency is subject to a type of deterioration termed "flavour reversion" when heated to temperatures used in baking or frying. Investigation of the course of hydrogenation of linseed oil by the spectral method of Mitchell, Kraybill, and Zscheile (11) has indicated that linolenic acid is converted to an isomeric linoleic acid; this acid differs from naturally occurring linoleic acid in that the double bonds are in such positions that diene conjugation is not produced by high-temperature saponification. In a typical hydrogenation, the concentration of the isomeric acid increased to a maximum, at about iodine number 120, of 18% of the total fatty acids, and at iodine number 80, at which point the plasticity was similar to that of a commercial shortening, the concentration of the isomer was 13%. Evidence is presented that the isomeric linoleic acid in partially hydrogenated linseed oil is responsible for the unpleasant flavour that develops when the oil is heated.


1992 ◽  
Vol 285 (2) ◽  
pp. 557-562 ◽  
Author(s):  
T Liang ◽  
S Liao

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.


Aquaculture ◽  
2019 ◽  
Vol 500 ◽  
pp. 550-561 ◽  
Author(s):  
Ivar Lund ◽  
Covadonga Rodríguez ◽  
Maria S. Izquierdo ◽  
Najlae El Kertaoui ◽  
Patrick Kestemont ◽  
...  

Author(s):  
Sushil Kumar ◽  
Sajjan Sihag ◽  
Zile Singh Sihag ◽  
Chandershekhar Santosh Patil ◽  
Surender Singh Dhaka ◽  
...  

Background: Supplementation of fat, especially those having unsaturated fatty acids has been proposed to carry positive effects on the reproductive organ, beside providing dietary energy to the animals. This experiment was designed to examine the effects of dietary ω-3 or ω-6 fatty acid (FA) rich oil supplementation on blood FA, metabolite and hormone concentrations; ovarian follicular growth and corpus luteum (CL) size in Sahiwal breed heifers.Methods: Eighteen heifers of 18.33±1.14 months of age and 194±4.16 kg of mean body weight were randomly assigned to 3 diets and individually fed as per ICAR (2013) diets. The diets include chopped wheat straw, green fodder and concentrate mixture containing either (i) no added PUFA rich oil but palm oil @ 3.5% (PO; n=6); (ii) 3.5% added soybean oil as ω-6 FA source (SO; n=6); or (iii) 3.5% added linseed oil as ω-3 FA source (LO; n=6).Result: SO increased (P less than 0.05) the plasma concentration of ω-6 FA while LO increased (P less than 0.05) the plasma ω-3 FA. Plasma glucose, triglyceride and non-esterified fatty acid (NEFA) concentrations was not affected due to different diets. Plasma total cholesterol and HDL-cholesterol were significantly higher (P less than 0.05) in SO and LO in comparison to PO. However, LDL-cholesterol was at par among all the treatments. Growth Hormone (GH) was not influenced due to different types of oil in heifers’ concentrate mixture. Insulin concentration increased (P less than 0.05) in LO compared to others. IGF-1 was statistically higher (P less than 0.05) in SO and LO as compared to CON, which among themselves also varied significantly. Plasma progesterone concentration at day 12 post estrous was higher (P less than 0.05) in LO. PUFA rich oil supplementation in the concentrate mixture of heifers (SO and LO) increased (P less than 0.05) the size of the ovulatory follicles as well as size of CL. It was inferred that feeding PUFA rich oil to pre-pubertal Sahiwal heifer’s results in advantageous changes in the blood metabolites, plasma hormones and ovarian functions.


2021 ◽  
pp. 8-12
Author(s):  
Иван Александрович Кечкин ◽  
Георгий Несторович Панкратов ◽  
Ирина Сергеевна Витол

Введение в ежедневный рацион продуктов, обогащенных эссенциальными нутриентами, является актуальной задачей стратегии здорового питания. В этой связи особое место занимают продукты переработки зерна, как основы пирамиды здорового питания. Среди наиболее востребованных незаменимых нутриентов следует выделить полиненасыщенные жирные кислоты, и особенно жирные кислоты семейства ɷ-3. Главным источником линоленовой кислоты из растительного сырья является льняное масло, которое может быть введено в виде тонкоизмельченных семян льна в состав хлебопекарной муки. Химический состав продуктов питания на зерновой основе, полученных с использованием традиционной технологии, характеризуется недостаточной сбалансированностью, невысокой пищевой и биологической ценностью. В связи с этим с целью расширения ассортимента зерновых продуктов функциональной направленности общего, диетического и профилактического назначения на основе полизерновых смесей разработаны методология управления мукомольными свойствами зернового сырья при его переработке для получения продуктов питания на зерновой основе заданного состава и свойств; показана возможность совместного размола пшенично-льняной смеси с получением муки, обогащенной незаменимыми жирными кислотами (НЖК) - омега-3 (линоленовая кислота) и омега-6 (линолевая кислота); сформированы новые виды муки, обогащенные незаменимыми жирными кислотами; определены некоторые физико-химические характеристики пшеничной муки, обогащенной НЖК; выявлены особенности хлебопекарных свойств пшенично-льняной муки. На основании динамики изменения показателя кислотного числа жира (КЧЖ) спрогнозирован срок безопасного хранения пшенично-льняной муки, который составил 9,4 месяца. The introduction of foods fortified with essential nutrients into the daily diet is an urgent task of a healthy eating strategy. In this regard, grain processing products occupy a special place, as the basis of the pyramid of healthy nutrition. Among the most demanded essential nutrients are polyunsaturated fatty acids and especially fatty acids of the ɷ-3 family. The main source of linolenic acid from plant raw materials is linseed oil, which can be added in the form of finely ground flax seeds to baking flour. The chemical composition of grain-based food products obtained using traditional technology is characterized by insufficient balance, low nutritional and biological value. In this regard, in order to expand the range of functional grain products for general, dietary and prophylactic purposes on the basis of polygrain mixtures, the following have been developed: a methodology for controlling the milling properties of grain raw materials during its processing to obtain food products based on a grain basis of a given composition and properties; the possibility of joint grinding of a wheat-flax mixture to obtain flour enriched with essential fatty acids (EFA) - omega-3 (linolenic acid) and omega-6 (linoleic acid) is shown; formed new types of flour, enriched with essential fatty acids; some physicochemical characteristics of wheat flour enriched with EFA have been determined; the features of the baking properties of wheat-flax flour are revealed. Based on the dynamics of changes in the acid number of fat (FAT), the period of safe storage of wheat-flaxseed flour was predicted, which was 9.4 months.


2020 ◽  
Vol 161 ◽  
pp. 01093
Author(s):  
I.S. Khamagaeva ◽  
N.A. Zambalova ◽  
A.V. Tsyzhipova ◽  
A.T. Bubeev

The relationship between the content of polyunsaturated fatty acids (PUFAs) of flaxseed oil and the cholesterol-metabolizing activity of various strains of bifidobacteria was studied. The optimum dose of linseed oil in a nutrient medium for the cultivation of bifidobacteria was selected to provide high cholesterol destruction compared to the control. Of all the studied strains of bifidobacteria, the most pronounced destructive activity against cholesterol is displayed by the strain Bifidobacterium longum DK-100, which, with the biomass growth in a nutrient medium of linseed oil destroys 74% of the total cholesterol. When studying the fatty acid composition of the biomass of bifidobacteria, the oleic acid was found to predominate among monounsaturated fatty acids, and the α-linolenic acid to prevail among polyunsaturated fatty acids, that amounted to 44-45%. A decrease in the content of linolenic acid during the cultivation of bifidobacteria was noted, which is probably due to their participation of bifidobacteria in the metabolism. As a result of the studies, the optimum conditions for the cultivation of bifidobacteria were selected and the technological parameters of producing dietary supplements were justified.


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