Proportions Of Trans Fatty Acids Research Articles

Proportions of trans fatty acids in erythrocytes of Canadian adults before the prohibition of partially hydrogenated oils in foods: results from the Canadian Health Measures Survey 2012–2015

BackgroundThe partially hydrogenated oil (PHO) prohibition came into effect in Canada in September 2018 to reduce the intakes of total trans fatty acids (t-TFAs) and industrially produced TFAs (i-TFAs). ObjectivesWe aimed to estimate the red blood cell (RBC) proportions of t-TFA (primary objective) and total 18:1 TFA (secondary objective) of adults in Canada before the PHO prohibition and to identify the population subgroups at risk of higher TFA intakes. MethodsWe pooled data from 4025 adult participants of the cross-sectional Canadian Health Measures Survey cycles 3 and 4 (2012–2015). We estimated mean proportions, relative to total fatty acids (FAs), of RBC t-TFA and 18:1 TFA and their associations with sociodemographic, health, and lifestyle characteristics using multiple linear regression models. ResultsThe nonadjusted mean RBC proportions of t-TFA and total 18:1 TFA were 0.59% (95% CI: 0.54, 0.63) and 0.27% (95% CI: 0.25, 0.29), respectively. In the adjusted models, the same participant characteristics were associated with t-TFA and 18:1 TFA but differences were generally smaller for 18:1 TFA than for t-TFA. Race, BMI, and alcohol intake were independently associated with RBC t-TFA and 18:1 TFA. Asian and Black participants had lower RBC t-TFA (−0.05% and −0.10% of total FA, respectively) than White participants. Obesity and high risk alcohol drinking were associated with slightly lower (≤0.06%) t-TFA proportions than lower adiposity and alcohol intake concentrations, respectively. ConclusionsPre-PHO prohibition in food in Canada, t-TFA proportions were relatively low compared with a proposed threshold of 1% of total RBC FAs, over which cardiovascular disease risk may be higher. Previous voluntary initiatives to reduce i-TFA in the food supply may explain these relatively low RBC t-TFA concentrations. Some population subgroups had higher baseline RBC TFA than other subgroups, but the physiological implications of these small differences, at relatively low baseline RBC TFA proportions, remain to be determined.

La carne di chiocciola, un’antica fonte di proteine nella dieta umana

The aim of this study was to determine the physicochemical parameters, i.e. water, protein, fat, ash, sodium and carbohydrate content and energy value, as well as fatty acid composition and pH of snail meat from two species, Cornu aspersum maximum and Cornu aspersum Müller. The snail meat was found to have relatively high protein content (13.12 g/100 g vs. 16.53 g/100 g), low fat content (0.89 g/100 g vs. 1.21 g/100 g), and low energy value (343.8 kJ vs. 379.2 kJ). The pH of snail meat was very high (8.59 vs. 8.19). On average, snail meat has a favourable fatty acid composition as it contains 27.08 wt. % saturated (SFA), 19.00 wt. % monounsaturated, and 53.92 wt. % polyunsaturated fatty acids (PUFA). It has a favourable PUFA/SFA ratio (1.99), but an unfavourable n-6/n-3 ratio (20.33) and a relatively high proportion of trans fatty acids (3.93 wt. %). The fatty acid profile of snail meat is dominated by linoleic acid (20.89 wt. %), arachidonic acid (13.27 wt. %), oleic acid (12.67 wt. %), nonadecanoic acid (10.23 wt. %), and stearic acid (10.08 wt.%). The aim of our study was also to verify the culinary value of snail meat. For this purpose, two snail meat pâtés of acceptable sensory quality were prepared. The panel evaluated the sensory quality of the pâté made from the meat (foot and liver) of the snail Cornu aspersum Müller significantly worse than the pâté made from the meat of the snail Cornu aspersum maximum, mainly due to the unpleasant aroma, in which the soapy, sweet and spicy components predominated, as well as the absence of the snail meat aroma.

Development of the optical sensor for discriminating isomers of fatty acids based on emissive network polymers composed of polyhedral oligomeric silsesquioxane

It was shown that water-soluble network polymers composed of polyhedral oligomeric silsesquioxane (POSS) had hydrophobic spaces inside the network because of strong hydrophobicity of the cubic silica cage. In this study, the water-soluble POSS network polymers connected with triphenylamine derivatives (TPA-POSS) were synthesized, and their functions as a sensor for discriminating the geometric isomers of fatty acids were investigated. Accordingly, in the photoluminescence spectra, different time-courses of intensity and peak wavelengths of the emission bands were detected from the TPA-POSS-containing solution in the presence of cis- or trans-fatty acids during incubation. Furthermore, variable time-dependent changes were obtained by changing coexisting ratios between two geometric isomers. From the mechanistic investigation, it was implied that these changes could be originated from the difference in the degree of interaction between the POSS networks and each fatty acid. Our data could be applicable for constructing a sensing material for generation and proportion of trans-fatty acids in the oil.

English

The objective of this study was to determine the nutrient composition of selected commercial biscuits in Malaysia. A total of six brands from each type of biscuit (chocolate chip, corn, cracker with sugar, vegetable flavoured cracker, cream filled, oatmeal, shortbread and fully coated chocolate wafer) and five brands of wholemeal crackers were sampled from local supermarkets in the Klang Valley. The total energy content in commercial biscuits was ranging from 453.30 to 499.25 kcal/100 g. Carbohydrate was the major macronutrient in commercial biscuits ranging from 56.86 to 66.07 g/100 g. The highest protein content was found in the wholemeal crackers (9.92 g/100 g) and the lowest protein content was found in the cream filled biscuits (5.65 g/100 g). Fat content lay in the range of 16.89 to 25.75 g/100 g. The major minerals detected in biscuits were sodium, followed by calcium and magnesium. The vitamin content in A and E of the biscuits examined was almost comparable. Small quantities of trans fatty acids were detected in all biscuits in the range of 0.02 to 0.68 g/100 g. These findings indicate that Malaysian commercial biscuits are a good source of carbohydrate (34.12-39.64 g per serving), calcium (26.09-384.67 g per serving), magnesium (10.42-37.24 g per serving) and contain low proportion of trans fatty acids (0.01-0.41 g per serving).

Chemical and sensory assessment of deep‐frying oil alternatives for the processing of French fries

The aim of the study was to evaluate volatile compounds as marker compounds for the edible oil deterioration during the production of deep‐fried French fries. Additionally the sensory characteristics (taste and smell) were assessed and results were compared with the results of the volatile compound analysis. A 32‐h deep‐frying experiment was performed and different frying oils, namely sunflower oil (SF), high‐oleic sunflower oil (HOSF), rapeseed oil (RO), high‐oleic rapeseed oil (HORO), and palm olein, were subsequently analyzed for their oxidative properties by the determination of their total polar material (TPM), polymerized triglycerides (PTG), peroxide value, anisidine value, as well as the fatty acid composition. In addition, analysis of the volatile compounds derived from the thermal degradation of the frying oils was performed by means of headspace‐GC/MS techniques (HS‐SPME‐GC/MS and DHS‐GC/MS). Multivariate statistical methods (principal component analysis with VARIMAX rotation) were applied to identify sensitive volatile lipid degradation indicators, enabling a differentiation of the various frying oils of different degrees of lipid oxidation just after 3 h of deep‐frying. E,E‐2,4‐decadienal and heptanal showed the greatest ability to differentiate between samples of various oxidative states, whereas E,E‐2,4‐heptadienal and E‐2‐decenal showed a reasonable correlation with well‐known lipid oxidation parameters, e.g., values for PTG or TPM. In addition to the chemical evaluation of the frying oils, the produced French fries were evaluated in terms of their taste and smell by an advanced scientific sensory method (balanced incomplete block design). French fries produced in conventional vegetable oils (SF and RO) were differentiated earlier from those prepared in fresh reference oil compared to HOSF and HORO. The perception of the French fries prepared in HOSF was comparable to those prepared in palm olein. Therefore, high‐oleic vegetable oils, especially high‐oleic SF, provide a frying oils alternative for the production of deep‐fried French fries, delivering low proportions of trans and saturated fatty acids.Practical applications: The combination of volatile compound analysis by headspace‐GC/MS techniques with multivariate statistical methods is a sensitive tool to detect quality changes in deep‐frying oils at an early stage of lipid deterioration. Evolved volatile marker compounds, e.g., E,E‐2,4‐heptadienal and heptanal correlated reasonably with quality parameters for the assessment of the thermal stability of frying oils, e.g., content of TPM polymerized trigylcerides. Comprehensive scientific sensory evaluations of frying oils revealed high‐oleic edible oils as promising frying oil alternatives for the processing of French fries providing low proportions of trans fatty acids and saturated fatty acids.

Trans Fatty Acid Content of Iranian Edible Oils

Clinical and epidemiologic studies showed that among dietary factors the type of fatty acids (FAs) in the diet plays an important role in determining risk of chronic disease. The aim of our study was to determine the levels of Trans FA (TFA) in edible oil samples consumed in Tehran, Iran analyzed by gas chromatograph (GC). The mean of total TFA was 0.45% ranging from (0.11% - 1.61%) for liquid frying oils and 2.92% ranging from (0.46% - 5.40%) for solid oils. The major TFA observed in these two groups was elaidic acid in solid oils. The highest content of total saturated fatty acid (SFA) was detected in solid oils with average of 32.07 and palmitic acid was the major SFA in these four groups. Linoleic and linolenic acid are the most important poly unsaturated fatty acid (PUFA). The variance in the percentage of TFA in the edible oils probably resulted from differences in the type of oils, quality, heating, processing technique and storage condition of the edible oils. The results indicated that, edible oils contain considerable proportions of trans fatty acids. Therefore, it is important to assess the content of TFA in edible oils in Iran.

Trans fatty acids effect on some serum enzymes and immunological parameters in Wistar albino rats

The effect of trans fatty acids on some serum enzymes and immunological parameters in male albino Wistar rats was evaluated in this study. Fifty (50) male Wistar albino rats weighing between 100-140g were divided into five groups of ten rats each. The animals were fed varying proportions of trans fatty acids (15% and 25%) respectively using margarine and thermoxidised palm oil as sources.The control received palletized grower’s feed. The feeding experiment lasted for eight (8) weeks after which the animals were sacrificed and sera collected for analyses. Results showed significant decrease/increase in levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) respectively.CD4+ levels and basophils count were increased in the test groups except group 3 compared to the controls. Lymphocytes showed significant decreases (P<0.05) in all the test groups except group 3 when compared to the control. Our findings did not reveal probable hepatotoxic effect and decreased immunity on consumption of of trans fatty acids.

Changes in Erythrocyte Membrane Trans and Marine Fatty Acids between 1999 and 2006 in Older Americans1–3

Over the last several years, national programs to lower the content of industrially produced (IP) C18:1 and C18:2 trans fatty acids in foods have been implemented, but whether this has resulted in lower blood trans fatty acid levels is unknown. Likewise, an increased perception of the health benefits of fish oils rich in EPA and DHA may have resulted in an increase in consumption and blood levels of these fatty acids. To explore these issues, we analyzed the changes in RBC fatty acid composition between the 7th (1998–2001) and 8th (2005–2007) examination cycles in a random sample of the Framingham Offspring cohort. This was a retrospective cohort study of 291 participants from whom blood was drawn at both examinations and for whom complete covariate data were available. Overall, the proportion of trans fatty acids in RBC changed by -23% (95% CI: -26 to -21%). RBC EPA+DHA proportions increased by 41% (95% CI: 31 to 52%) in 38 individuals who were taking fish oil supplements at examination 8, but in 253 participants not taking fish oil, the proportion of RBC EPA+DHA did not change. In conclusion, in a random subsample of Framingham Offspring participants with serial observations over 6.7 y, the proportion of trans fatty acids in RBC decreased. Those of EPA+DHA increased in people taking fish oil supplements. These changes could potentially translate into a lower risk for cardiovascular disease.

Lipid profiles and trans fatty acids in serum phospholipids of semi-nomadic Fulani in northern Nigeria.

The Fulani are semi-nomadic pastoralists of West Africa whose diet, culture, and economy are centred on cattle. Previous studies have shown that the Fulani of northern Nigeria derive 50% of their total calories from fat and 30% of their calories from milk, cheese, yogurt, and butter oil that contain significant amounts of trans fatty acids (TFAs), primarily vaccenic acid, which raise total serum cholesterol and low-density lipoproteincholesterol (LDL-C), and lower high-density lipoprotein-cholesterol (HDL-C). The study was conducted to know how the consumption of relatively large amounts of dairy products by adult Fulani affected the TFA content of their serum phospholipids. Blood samples were collected from 22 male and 29 female Fulani, aged 35-60 years, who were living in rural areas of Gombe state in northeastern Nigeria. The total serum phospholipid fraction was isolated, and its fatty acid composition was determined. Surprisingly, vaccenic acid was not detected, and three other TFAs--18:1-t6, 18:1-t9, and 18:2-t9,t12--together accounted for only 0.16% of the total fatty acid. The mean serum total cholesterol, LDL-C, and triglyceride concentrations of the subjects were within the normal range for populations in developed countries; however, at 32 mg/dL, the mean serum HDL-C concentration of the Fulani males was slightly below the lower limit of the reference range. No correlations were observed between the total TFA percentage or that of the three individual TFAs and any of the parameters of the serum lipid profile. These findings indicate that, with respect to TFAs at least, the fatty acid pattern of the serum phospholipids of Fulani pastoralists does not reflect the high TFA content of their traditional diet. Despite the consumption of rumenic acid-rich dairy products, for unknown reasons, the semi-nomadic Fulani manage to maintain a low level of TFAs in their blood and a relatively healthful serum lipid profile. While the mechanism that accounts for this disconnect between the consumption of TFAs by Fulani pastoralists and the proportion of TFAs in their serum phospholipids is obscure, possibilities include discrimination against rumenic acid during the process of triglyceride synthesis and chylomicron synthesis in the intestine and the preferential oxidation of TFAs by Fulani the people compared to other ethnic groups.

EFFECTS OF ZERO‐TRANS INTERESTERIFIED AND NON‐INTERESTERIFIED SHORTENINGS AND BREWER'S SPENT GRAIN ON COOKIE QUALITY

ABSTRACT The effects of non‐interesterified (non‐in‐es) and chemically interesterified (in‐es) cottonseed oil (CO), palm oil (PO) and CO : PO blend (1:1, weight basis) and brewer's spent grain (BSG) on quality of cookies were studied. Incorporation of non‐in‐es and in‐es CO and CO : PO blend improved the nutritional value of the cookies by altering the fatty acid composition. The experimental shortenings had zero‐trans fatty acids (TFA) and considerably higher linoleic acid contents than hydrogenated shortening (HS). in‐es PO and CO : PO blend samples had lower solid fat content than their non‐in‐es counterparts and this resulted in higher spread ratios in in‐es incorporated cookies. As expected, addition of BSG significantly increased (P &lt; 0.05) the total dietary fiber (TDF) content of cookies. Cookies with modified fatty acid composition and 4.4‐fold higher TDF have been produced by using non‐in‐es and in‐es CO and CO : PO with 15% BSG, without significant adverse effects on sensory properties.PRACTICAL APPLICATIONSHydrogenated shortenings (HSs) are the most important source of fat in cookies and might have high proportions of trans fatty acids (TFAs). A high intake of TFA is associated with increased risk of coronary heart disease and the intake should be reduced to minimize health risks. In this work, the production of zero‐trans interesterified and non‐interesterified shortenings and their utilization in high‐fiber cookies were investigated. The results indicated that some of the experimental in‐es and non‐in‐es shortenings and 15% brewer's spent grain could be used for production of cookies with zero TFA and higher unsaturated fatty acids and total dietary fiber contents without detrimentally affecting their sensory properties. The in‐es shortening incorporated cookies had higher spread ratios and color values than their non‐in‐es counterparts.

Trans fatty acid content of Brazilian biscuits

The fatty acid composition and trans fatty acid (TFA) contents of samples of five brands Brazilian cream cracker biscuits were determined by gas–liquid chromatography, using a polar 100 m capillary column CP Sil-88 and flame ionization detection. The identification of fatty acids done by equivalent chain length for trans fatty acids. Total TFA ranged from 12.2% to 31.2% of total fatty acid and the mean was 20.1%. Trans 18:1 isomers were the major group of TFA present in all the analyzed brands, representing 83.2% of total trans isomers. The mono- trans 18:2 isomer content ranged from 1.6% to 4.2% of total fatty acids, this being the most prevalent group of trans polyunsaturated acid. The di- trans 18:2 isomer (9 t, 12 t) was found at very low levels (0.10–0.15% of total fatty acids). Trans 18:3 isomer content ranged from 0.11% to 0.75% of total fatty acids representing 24.4–75.0% of total α-linolenic acid. The results indicate that Brazilian cream cracker biscuits contain considerable proportions of trans fatty acids, both monounsaturated and polyunsaturated.

TransFatty Acids in Bakery Products from 14 European Countries: the TRANSFAIR Study

The fatty acid composition of bakery products from 14 European countries was analyzed with particular emphasis ontransfatty acids. The proportion oftransfatty acids in cookies and biscuits ranged from <1 to 28%.Transfatty acids content in sweet pastry ranged from practically 0 to 33%. Croissants and doughnuts had varying amounts oftransfatty acids, with the highest value of 15% in croissants and 32% in doughnuts. The totaltransfatty acid content in pizzas was mostly in the same order and varied from <1% to 5%. Most hydrogenated marine oil-based bakery products were found in Iceland and in Norway. In Finland, Portugal, Italy, Netherlands, and United Kingdom no bakery products based on hydrogenated marine oils could be identified. Bakery products based on hydrogenated vegetable fats were present in almost every country. It can be concluded that in bakery products it is difficult to identify the presence oftransfatty acids.

TransFatty Acids in Dietary Fats and Oils from 14 European Countries: The TRANSFAIR Study

The fatty acid composition of dietary fats and oils from 14 European countries was analyzed with particular emphasis on isomerictransfatty acids. The proportion oftransfatty acids in typical soft margarines and low-fat spreads ranged between 0.1 and 17% of total fatty acids and that ofcis-unsaturated fatty acids between 55 and 81%. Hard household margarines and industrial fats for cooking and baking (shortenings) had slightly higher proportions oftransfatty acids and highest amounts, up to 50%, were found in fats for deep frying. Vegetable oils contained only small amounts oftransfatty acids, usually less than 1%. Isomers of C18:1 comprised up to 94% of thetransfatty acids in hardened vegetable oils and 52–68% in butter, whereas hardened fish oils showed a more even distribution oftransmonoenoic fatty acids between C16:1 and C22:1, and C18:1 isomers contributed by 28–42% to totaltransfatty acids. Fat spreads with very low content (<1%) oftransfatty acids were found in all but one of the countries, and a general tendency to products lower intransfatty acids was observed in most countries for soft margarines and low-fat spreads but not for industrial fats and fat products for cooking and frying. The fatty acid composition of the spreads indicated that both C12–16 saturated fatty acids andcis-unsaturated fatty acids had been used to replacetransfatty acids in the low-transfatty acid products in the different countries but the use of increased amounts of stearic acid was very limited.

TransFatty Acids in French Fries, Soups, and Snacks from 14 European Countries: The TRANSFAIR Study

In the TRANSFAIR study, foods contributing to 95% of total fat intake were collected in 14 European countries. In addition to edible fats, dairy, meat, and bakery products some specific food items with relatively high amounts oftransfatty acids were found. French fried potatoes, both those from fast-food restaurants and those from the supermarkets (including potato chips), contained mostly between 12 and 35%transfatty acid, but some products fried in animal fat or vegetable oil contained lower proportions between 0.5 and 7% total fatty acids. Deep-fried croquettes were also rich intransfatty acids. Microwave popcorn samples contained 27–34%transfatty acids. Ready-made popcorn was low intransfatty acids but generally contained even more saturated fatty acids. Dry soup and sauce mixes and cubes and high-fat, frosted breakfast cereals were other examples of foods that often contained >10%transfatty acids. It is concluded that any deep-fried product such as French fried potatoes may contain high proportions of isomerictransfatty acids. Processed foods with a long shelf life such as dry soup powders and cubes, savory snacks, and popcorn often contained relatively high proportions oftransfatty acids, although the contributions of these products to total fat intake are probably small. The foods and snacks with a high proportion oftransfatty acids usually contained less saturated fatty acids and morecis-unsaturated fatty acids than respective foods prepared with low-transsaturated vegetable fats or animal fats.

TransFatty Acids in Dairy and Meat Products from 14 European Countries: The TRANSFAIR Study

The fatty acid composition of dairy products and meat from 14 European countries was analyzed with particular emphasis ontransfatty acids. In cow's milk, butter, and cheese the proportions oftransfatty acids ranged between 3.2 and 6.2% of fatty acids. C18:1 isomers comprised about 60% and C16:1 and C18:2 isomers about 15% each of totaltransfatty acids. Goat's and sheep's milk and cheese contained between 2.7 and 7.1%transfatty acids. Summer milk contained up to 57% moretransfatty acids, both C18:1 and C18:2 isomers, morecis-unsaturated and less saturated fatty acids than winter milk. Ice-cream with partially hydrogenated vegetable oils contained between 21 and 31%transfatty acids and low-transmodified-fat ice-cream between 0.2 and 0.9%. The high-transice-cream samples contained morecis-unsaturated and less saturated fatty acids than most dairy-fat and low-transproducts. Beef contained 2.8–9.5% and lamb meat 4.3–9.2%transfatty acids whereas pork (0.2–2.2%) and chicken (0.2–1.7%) and meat from other nonruminants were lower intransfatty acids. With very few exceptions, sausages contained pork and showed lowtransfatty acid levels. In conclusion, ruminant fats contained moderate amounts oftransfatty acids, mainly C18:1 isomers. There were considerable differences both between and within the countries, probably due to seasonal factors and differences in feeding practices and the age of the animals.

Fatty acid composition of adipose tissue, an indication of dietary fatty acids, and breast cancer prognosis.

Fatty acid composition of adipose tissue is an indicator of the long-term ingestion pattern of several specific fatty acids. There is good correlation of antecedent diet with the essential fatty acids, and there is reflection of the diet with the fatty acids that can be synthesized. The relationship between the fatty acid levels and lymph node status and clinical outcome was examined. At the time of diagnostic surgery, 161 women with clinical stage T1NO breast cancer had subcutaneous adipose tissue (breast and abdominal) aspirated. The concentrations of 35 fatty acids, seven summed classes, and six fatty acid groups were measured by capillary gas chromatography. Lymph node status was determined with axillary dissection, and patients were followed-up (mean, 7.3 years) for clinical outcome. There was no significant association of any adipose tissue fatty acids with overall survival, although few (16 of 161 women) died of breast cancer. However, the odds of having positive lymph nodes (57 of 161 women) were significantly higher for women with a greater adipose tissue proportion of oleic acid (odds ratio [OR], 7.56; 95% confidence interval [CI], 1.78 to 32.1) or total saturated acids (OR, 8.43; 95% CI, 1.48 to 40.0) and significantly lower with a higher proportion of trans fatty acids (OR, 0.24; 95% CI, 0.07 to 0.77), as assessed by multivariate logistic regression. These data support previous research with dietary questionnaire methodology, suggesting that specific dietary fatty acids may be associated with breast cancer promotion. Further research with long-term clinical follow-up is necessary to investigate these observations in large, diverse populations before dietary recommendations can be envisioned.

Effect of dietary trans fatty acids on microsomal enzymes and membranes.

Three groups of rats were maintained on diets containing different proportions of trans fatty acids (0, 18.3 or 36.6% of the total fatty acids) for eight weeks. No differences in body weight were observed among the three groups, but the fat cell size, determined in epididymal fat, differed significantly between the controls and the rats fed diets containing trans fatty acids. The supernatant obtained by centrifuging homogenates of liver from the rats at 9000 X g (S-9 fraction) was used as an activator in a bacterial test for mutagenicity of 2-aminofluorene and aflatoxin B1 using Salmonella typhimurium strains TA 98 and TA 100, respectively. The mutagenicities of 2-aminofluorene in strain TA 98 and of aflatoxin B1 in strain TA 100 were significantly lower with the liver S-9 fraction from rats fed a diet containing 36.6% trans fatty acids than with the liver S-9 fraction from rats fed a control diet with no trans fatty acids.

Reactivities of highly unsaturated fatty acids for the hydrogenation on nickel catalyst

The reactivities of the C 20 highly unsaturated fatty acids (20:5, 20:4, 20:3 etc.…) during heterogeneous hydrogenation on nickel catalyst have been studied using a computer program. Three parameters are required to determine the hydrogenation rate constant of the different fatty acid classes; the C 20 fatty acid composition of the starting oil, the C 20 fatty acid composition of a partially hydrogenated oil (PHO) and the time of reaction. It is shown that, in order to minimize the experimental errors, the PHO must be selected in such a way that the induction period is over and that this oil still contains appreciable amounts of 20:5 and 20:4. Very little difference was found for the reactivities of the 20:5, 20:4 and 20:3 acids. The major difference among unsaturated fatty acids was found to be between the 20:2 and 20:1 isomers for a hydrogenation effected according to common commercial practices. The computer program is a general one also useful for the prediction of the fatty acid composition of slightly hydrogenated oils, but is not suitable for oils hydrogenated to very low iodine values, or for those containing high proportions of trans fatty acids.