Flaxseed form influences egg production and the nutritional and sensory quality of shell eggs

Abstract

N-3 fatty acid (FA)-enriched shell eggs have been proposed as an economical food source for increasing n-3 FA consumption. Diminution of oxidative stability can reduce n-3 FA nutritional quality, therefore the oxidative stability of laying hen ration supplements is critical. This study was designed to determine egg production variables, n-3 FA incorporation, and yolk thiobarbituric acid reactive substances (TBARS) when hens were fed whole or ground flaxseed. Gold flaxseed (whole or ground form) fed at levels of 5 or 15% were compared to a 1.5% menhaden oil or a typical control layer ration during a 10 week feeding trial. Eggs were collected and fatty acid composition determined during weeks 4 and 5 of the feeding trial. The TBARS content of yolk was also determined at this time. As dietary flaxseed increased, total n-3 FA (C 1 8:3 + C20:5 + C22:6) increased proportionately. Marine n-3 FA (C20:5 + C22:6) did not increase proportionately with increasing dietary flaxseed. Seed form did not influence n-3 FA deposition at the 5% level of flaxseed; however, ground 15% flaxseed resulted in greater total n-3 fatty acid deposition than whole 15% flaxseed. Yolk TBARS were not significantly different due to seed form. Eggs were collected from hens fed control and 15% whole and ground flaxseed diets during week 10 of the feeding trial for fatty acid, trained and consumer sensory panel, and headspace analyses. Trained panelists (n=l 1) scored scrambled eggs on 25 aroma, flavor, and aftertaste attributes. Eggs from flaxseed fed hens scored higher than controls in chemical flavor and fishy aroma and flavor, and lower than controls in sweet aroma and flavor and egg aroma and flavor. Dietary flaxseed significantly (P<.05) affected the concentration of 13 volatiles separated from heated egg blends. Headspace volatile compounds were significantly (P<.05) correlated with sensory attributes and omega-3 fatty acids. Models were developed to predict the overall flavor of eggs from eggs from hens fed flaxseed using the trained sensory attributes and the peak areas of headspace volatile compounds. Consumer panelists were unable to discern between eggs from hens fed whole or ground flaxseed.