The Influence of Butter and Oils on Oxidative Reactions during In Vitro Gastrointestinal Digestion of Meat and Fish.

Thomas Van Hecke,Stefaan De Smet

doi:10.3390/foods10112832

Abstract

Oxidative reactions during cooking and gastrointestinal digestion of meat and fish lead to the formation of various lipid- and protein oxidation products, some of which are toxic. In the present study, it was investigated how the addition of 3% butter or oils affect lipid- and protein oxidation during cooking and in vitro digestion of meat (chicken thigh, chicken breast, beef) and fish (mackerel, cod). These muscle foods were selected based on their differences in heme-Fe and PUFA contents, and n-6/n-3 PUFA ratio, and therefore varying potential to form oxidation products during digestion. Without additional fat, mackerel digests displayed the highest n-3 PUFA oxidation (4-hydroxy-2-hexenal, propanal, thiobarbituric reactive acid substances), and chicken digests the highest n-6 PUFA oxidation (4-hydroxy-2-nonenal, hexanal), whereas both lipid- and protein oxidation (protein carbonyl compounds) were low in cod and beef digests. Lipid oxidative reactions were generally not altered by the addition of butter to any muscle matrix, whereas the addition of fish oil and safflower oil in different ratios (3:0, 2:1, 1:2, 0:3) as n-3 PUFA and n-6 PUFA source respectively, stimulated oxidative reactions, especially during digestion of beef. Since beef was considered the muscle matrix with the highest potential to stimulate oxidation in the added fat substrate, in a second experiment, beef was cooked and digested with 3% butter or seven commercial vegetable oils (sunflower-, maize-, peanut-, rapeseed-, olive-, rice bran- or coconut oil), all labeled ‘suitable for heating’. No relevant oxidative reactions were however observed during digestion of beef with any of these commercial vegetable oils.

Highlights

With the aim to reduce the risk of developing cardiovascular disease, many nutritional and health bodies promote the replacement of dietary saturated fatty acids (SFA) with monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA)
Among in vitro digested muscle foods originating from 18 different mammal, poultry and fish species, beef contained relatively high amounts of pro-oxidant heme-Fe, but, due to their very low content of oxidizable PUFA, one of the lowest amounts of lipid- and protein oxidation products were found in their digests [5], which agrees with the findings previously reported by Steppeler et al [6]
A relevant decrease in the (LC) n-6/n-3 PUFA ratio was observed when fish oil was added to chicken or beef

Summary

Introduction

With the aim to reduce the risk of developing cardiovascular disease, many nutritional and health bodies promote the replacement of dietary saturated fatty acids (SFA) with monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). The Flemish dietary guidelines advise to replace butter as much as possible with vegetable oils for culinary preparations [1]. Several oils are rich in PUFA which are sensitive to oxidative damage during storage and gastrointestinal digestion. The consumption of turkey meat increased circulating ox-LDL in humans, which was related to the oxidation of PUFA during gastrointestinal digestion of the meat [2]. In the latter study, marinating the turkey with red wine reduced lipid oxidation and inhibited an increase of ox-LDL in blood

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