n-3 enrichment of chicken meat. 2. Use of precursors of long-chain polyunsaturated fatty acids: linseed oil

Effect of dietary fat sources and zinc and selenium supplements on the composition and consumer acceptability of chicken meat

A factorial design was used to study the effect of changes in broiler feed on the composition and consumer acceptability of chicken meat. One week before slaughter, 1.25% dietary fish oil was removed from the feed and replaced by other fat sources (animal fat or linseed oil) or we continued with fish oil, and diets were supplemented with Zn (0, 300, or 600 mg/kg), and Se (0 or 1.2 mg/kg as sodium selenite or 0.2 mg/kg as Se-enriched yeast). The changes in dietary fat led to distinct fatty acid compositions of mixed raw dark and white chicken meat with skin. The fish oil diet produced meat with the highest eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) content, whereas the linseed oil diet led to meat with the highest content in total n-3 polyunsaturated acids (PUFA), especially linolenic acid. However, meat from animals on the animal fat diet was still rich in very long-chain n-3 PUFA. Se content was affected by Se and Zn supplements. Se content increased with Zn supplementation. However, only Se from the organic source led to a significant increase in this mineral in meat compared with the control. Consumer acceptability scores and TBA values of cooked dark chicken meat after 74 d or after 18 mo of frozen storage were not affected by any of the dietary factors studied.

Influence of dietary lipid source and strain on fatty acid composition of Muscovy duck meat

A trial was conducted to study the effect of dietary 2% soya bean oil and dietary 2% fish oil (FO) on fatty acid composition of breast meat of two different Muscovy duck (Cairina moschata domestica L.) strains. The two strains were a broiler strain selected for meat production and an unselected rural strain. Fatty acid composition of breast muscle was deeply influenced by lipid source. Dietary FO improved the long chain polyunsaturated fatty acids (LC-PUFAs) of omega 3 series content, while the content of LC-PUFAs of omega 6 series was reduced. Differences in susceptibility in lipid manipulation were found between the two groups of animals suggesting the highest capability of animals belonging to the rural strain in stocking arachidonic acid in breast muscle. As the fatty acid profile of Muscovy duck meat can be considerably modified by changing the fatty acid composition of the diet, and dietary FO represents an easy way to reach this goal, human intake of healthy n-3 LC-PUFAs could be enhanced using this enriched poultry meat, even if the influence of FO on organoleptic characteristics (i.e. off-flavours) must be evaluated.

n-3 enrichment of chicken meat. 1. Use of very long-chain fatty acids in chicken diets and their influence on meat quality: fish oil

We assessed the effect of a diet supplemented with fish oil (FO) on the performance, fatty acid (FA) composition, quality, and sensory traits of broiler meat. Diets enriched with 0, 2, or 4% FO plus tallow (T) up to 8% added fat (T1, T2, and T3, respectively) were given to the birds throughout a 38-d growth period. T3 was replaced by a mixture of FO, linseed oil (LO), and T (1, 3, and 4% respectively) for 1 wk (T4) or 2 wk (T5) before slaughter. Meat quality, taste, and FA profile were determined. Higher final weights were recorded for birds fed T3, although feed efficiency was not affected. Other performance or objective meat quality parameters did not show significant differences among treatments. High FO concentrations decreased the saturated and monoenoic FA contents in the thigh samples. The amount of polyunsaturated fatty acids (PUFA) increased when added to the diet (FO diets), mainly as long-chain n-3 FA [eicosapentaenoic fatty acid (EPA), docosapentaenoic fatty acid (DPA), and docosahexaenoic fatty acid (DHA)]. On the other hand, levels of total n-6 FA resulted in slight changes, mostly in linoleic acid (LA). By replacing the FO diet with the experimental mixture (T4, T5), the n-3 and n-6 FA contents increased, mainly in the form of linolenic acid and LA, respectively, only 1 wk later. After 1 wk of T4, the DHA levels in chicken decreased. Sensory panelists could not identify the meats from T4 and T5 as being different from the control diet (T1).