Dietary conjugated linoleic acid with fish oil alters yolk n-3 and trans fatty acid content and volatile compounds in raw, cooked, and irradiated eggs.
We investigated the effect of dietary conjugated linoleic acid (CLA) along with n-3 polyunsaturated fatty acid (n-3 PUFA) on yolk fatty acid composition and volatile compounds in eggs that were raw (RA), hard-boiled (HB), or hard-boiled, irradiated (HBI, 2.5 kGy). Single Comb White Leghorn laying hens (n = 40) were randomly assigned to one of the four experimental diets containing 0, 0.5, 1.0, or 2.0% CLA. Menhaden oil was used as the source of n-3 PUFA. Eggs collected after 6 wk of feeding were analyzed for fatty acids and volatile compounds. The content of docosahexaenoic acid (C22:6 n-3) was reduced (P < 0.05) in eggs from hens fed the 2.0% CLA diet. Eggs from hens fed 0.5% CLA incorporated the highest concentration of docosahexaenoic acid (P < 0.05) with a concomitant reduction in arachidonic acid (P < 0.05). The yolk contents of cis-9 trans-11 CLA and trans-10 cis-12 CLA increased linearly (P < 0.05) as the dietary CLA supply increased. Total monounsaturates were reduced (P < 0.05) with an increase in saturates in yolk. No difference was observed in the total PUFA content of eggs. Total volatiles were reduced in RA eggs from 1.0 and 2.0% CLA diets. 2-Propanone, hexane, and methyl cyclopentane were the major volatiles in RA eggs and were reduced by dietary CLA at 1.0 and 2.0%. Acetaldehyde, pentane, propanol, acetic acid methyl ester, acetic acid ethyl ester, propionic acid methyl ester, 2-methylmethyl propionic acid, 2-propanone, and octane were the major volatiles in HB eggs and were reduced by 2.0% CLA (P < 0.05). No difference was observed in the acetaldehyde, pentane, propanol, acetic acid ethyl ester, octane, or total volatile content of HBI eggs.
Cherian
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Department of Animal Sciences, Oregon State University, Corvallis 97331-6702, USA. gita.cherian@orst.edu
Goeger
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MP
Ahn
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DU
D000818:Animals; D016718:Arachidonic Acid / Q000032:analysis; D002645:Chickens; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage*; D004281:Docosahexaenoic Acids / Q000032:analysis; D004530:Egg Yolk / Q000737:chemistry*; D004531:Eggs / Q000032:analysis*; D005227:Fatty Acids / Q000032:analysis*; D015525:Fatty Acids, Omega-3 / Q000032:analysis; D005260:Female; D005395:Fish Oils / Q000008:administration & dosage*; D005514:Food Irradiation; D006358:Hot Temperature; D019787:Linoleic Acid / Q000008:administration & dosage*; D014835:Volatilization
D004041:Dietary Fats; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; C033266:Menhaden oil; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D019787:Linoleic Acid