PRESERVATION OF EGG QUALITY USING GRAPE POMACE CAKES AS A NATURAL ANTIOXIDANT IN THE DIETS OF LAYING HENS ENRICHED IN OMEGA 3 FATTY ACIDS

Margareta Olteanu, Rodica Diana Criste, Tatiana Dumitra Panaite, Mariana Ropota, P.Al. Vlaicu, Raluca Paula Turcu, Cristina Soica, Petruta Visinescu

Abstract
   For the antioxidant effect evaluation of a winery by-product - the grape pomace cakes, a 4-week trial was conducted on 180 Lohmann Brown laying hens, aged 52 weeks. The layers were assigned to three groups: a control group (C) and two experimental groups (E1 and E2), with 60 hens/ group, housed in standard Zucami type cages (2 hens/cage). Compared to the control formulation, the experimental formulation included 5% flax meal, enriched in polyunsaturated fatty acids and as antioxidants 100 mg vitamin E/kg feed (E1); 2% grape pomace cakes (E2). Forty eggs/group were randomly collected in the end of the trial, 10 eggs/group being stored at +20°C and 10 eggs/group at +4°C, for 14 and 28 days in order to determine their fatty acids content and the quality preservation over time. After 14 days, eggs stored at +4°C has significantly (P<0.05) higher values of the Haugh unit, compared to those from 28 days, with comparable values for both experimental groups and control group. In contrast, the eggs stored at room temperature (+20°C), has lower values of the Haugh unit in both storage periods (14 and 28 days), compared to those stored at +4°C, without significant differences between groups (P>0.05), although experimental groups included flax meal. The results regarding the freshness of the eggs stored in the fridge (+4°C) for 14 days showed a 20% AA eggs in E2 group, while in the other groups were no AA eggs. Only group E2 had 10% eggs, stored at +20°C for 14 days, with grade A freshness, compared to 0% for groups C and E1. The grape pomace cakes had comparable effects with vitamin E on the preservation of egg quality over time, thus it can be affirmed that the grape pomace cake diet is effective in maintaining the quality of eggs enriched in polyunsaturated fatty acids over time.

Key words: antioxidants; grape pomace cakes; eggs; quality