Fatty Acid Composition Of Foods Research Articles

In Situ Preparation of Fatty Acid Methyl Esters for Analysis of Fatty Acid Composition in Foods

ABSTRACTLipid extraction preceding fatty acid methyl esters (FAME) preparation for gas chromatography is time‐consuming and cumbersome. We omitted the lipid extraction and performed in situ transesterification (ISTE) by heating lipid‐containing foods at 90°for 10 min after adding 0.5N NaOH in methanol for methanolysis and continued heating another 10 min for further methylation after adding 14% BF3 in methanol. FAME prepared by ISTE showed fatty acid composition virtually identical to FAME prepared after lipid extraction from powder, liquid, phospholipid‐rich, and tissue products. Due to its simplicity, speed, and reduced organic solvent usage, ISTE should be useful to determine overall fatty acid composition of foods.

Preliminary study: Cholesterol, total fat, and fatty acid composition of foods and dishes commonly consumed in Bahrain

Cholesterol, total fat, and fatty acid profile of 8 ready-made foods and I 1 dishes consumed in Bahrain were analyzed. The results revealed that the levels of cholesterol were low in many ready-made foods, but were relatively high in most home-prepared dishes analyzed. The highest level of cholesterol was observed in elbah, 306.5 mg/ 100 g dry weight (eggs and whole milk are the main ingredients in this dish). Fast foods such as Kentucky fried chicken, hamburger, and tikkah (grilled meat) have a high concentration of cholesterol. Fat level was high in most foods and dishes analyzed (it ranged from 15.5 to 70.8 g/ 100 g dry weight). The fatty acid analysis showed that oleic, linoleic, and palmitic acids were the predominant fatty acids in both ready-made foods and dishes. There are at least eight Bahraini foods and dishes that contain high levels of linoleic acid. The present study contributes to the data base for food composition in Bahrain.

Determination of Fatty Acid Composition of Food Containing Short Chain Fatty Acids

Because of the high volatility and water solubility of short chain fatty acids and their methyl esters, analysis of the fatty acid composition of food lipids in which they are present is more difficult than that of lipids containing only long chain fatty acids. The GLC analysis of such lipids of small amount (about 100mg) was established in the present study as follows: a lipid was methylated with diazomethane and Na-methylate, and the produced fatty acid methyl esters were extracted in n-hexane. The short chain (413 and 16:0) fatty acid methyl esters were measured by temperature programmed GLC on 15% OV-275 column, and long chain (1424) fatty acid methyl esters by isothermal GLC on a suitable column for the analysis of fatty acid methyl ester such as DEGS. To determine the complete fatty acid (424) composition, these data of fatty acid methyl esters contents were combined by mediation of methyl palmitate amount, since palmitic acid is the major fatty acids in many food lipids. The fatty acid composition of butter fat, margarine (containing milk fat) fat and coconut oil was determined, and the recovery of lipid as total fatty acid methyl esters was 97.6% butter fat, 98.5% margarine fat and 97.9% coconut oil, respectively.

Lipid conversion factors for calculating fatty acid contents of foods

Abstract and SummaryThe U.S. Department of Agriculture is searching the world literature published since 1960 for data on food lipids and their fatty acid composition. These data are being used to update and expand the national tables of food composition and to establish a computerized nutrient data bank. Customarily, investigators report fatty acid data in terms of weight percent of total methyl esters. For the benefit of users of nutrient tables, relative amounts of com‐ponent fatty acid esters should be converted to grams fatty acid (as free acid) per 100 grams food. For this purpose, conversion factors, defined as the weight of fatty acids in 1 gram of fat, were derived for various food products. Derivation of, and basis for, factors and their application are described for selected food products. Variables affecting factors are also dis‐cussed. Investigators should include, in reports on fatty acid composition of foods, information on total lipid content and on the fatty acid content of the lipid. The latter values are readily obtained by a saponification procedure, complete acid hydrolysis, or if desired, by lipid class analysis.

Lipids and fatty acids of important finfish: new data for nutrient tables.

AbstractThere is an urgent need for thorough and reliable information on the lipid content and fatty acid composition of food. Data on fish lipids (1960 to the present) have been collected and evaluated for the preparation of nutrient and food composition tables for this important commodity. Some factors affecting these data include the lack of standardization in fish nomenclature, cut of fish, season and location of catch, and variability of methods of analysis. The derivation and use of conversion factors relating wt percent methyl ester data in the literature to g fatty acid/100 g fish are described. Tabulated data are presented for total lipid and 14 fatty acids in 11 important finfish.

Liver cholesterol esters composition in guinea pigs with chronic vitamin C deficiency.

In the liver of male guinea pigs with chronic latent vitamin C deficiency an accumulation of cholesterol and changes in fatty acid composition of cholesterol esters were observed. The character of these changes depends on the fatty acid composition of food. Similar changes can be evoked in normal guinea pigs by giving them the same diets with an addition of 0.3% cholesterol. During cholesterol accumulation in the liver induced by hypovitaminosis C or the administration of exogenous cholesterol, liver cholesterol is esterified according to the composition of the fatty acid pool reflecting fatty acid composition of the diet.

Modifying the Fatty Acid Content of the Diet

Physicians are prescribing diets modified in fatty acids for patients with coronary artery disease. Dietitians will want to know what the fatty acid composition of foods is and how to plan diets low in saturated fatty acids, high in polyunsaturated fatly acids, and others. The authors have planned several regimens illustrating different modifications.