67D-16 |
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V. PARDIO1, L. Landín1, K. Waliszewski2, A. Bringas1, R. Loeza1, and F. Pérez-Gil3. (1) Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Avenida Circunvalación esq. Yáñez s-n, Veracruz, 91710, Mexico, (2) Unidad de Investigacion y Desarrollo en Alimentos, Instituto Tecnologico de Veracruz, M.A. de Quevedo 2779, Veracruz, 91700, Mexico, (3) Departamento de Nutrición Animal, Instituto Nacional de Investigaciones Biomédica y de la Nutrición Salvador Zubirán, Vasco de Quiroga 15, México D.F., 14000, Mexico The positive effect of soybean soapstock on the polyunsaturated fatty acid composition of hen egg yolk was confirmed previously. However, a higher degree of unsaturation leads to oxidation of egg lipids. The aim of the study was to evaluate the effect of storage on the fatty acid composition of the egg yolk from hens fed soybean soapstock, as the lipid composition has been an area of primary concern. A 128 laying hens 20 weeks of age were allotted to two dietary treatments replicated eight times randomly with 8 birds for replicate. The diets were sorghum-meal based, isocaloric, and isonitrogenous. Diet T4 had 100% of soybean soapstock, added in the amount to reach 1.5% linoleic acid and complemented with soybean oil, and the control diet T5 had 100% soybean oil. Four eggs from each replicate were collected weekly and stored at 4±1°C and 28±1°C in temperature control chambers during 4 weeks. Analysis of the fatty acid composition was carried out by gas chromatography and reported as a percentage. Data were analyzed by ANOVA (P<0.05) and significant differences among treatment means were analyzed by Tukey’s test using Minitab 13.0 statistical program. Results indicated that the percentages of C18:1,C18:3g and a, C20:5, and C22:5 fatty acids in the egg yolks of hens fed with diets T5 and T4 did not change significantly when stored at both temperatures. Significant reduction in yolk percentages of C16:0, C18:0, C16:1, C18:2, C20:4, and C22:6 fatty acids from both treatments after 4 weeks of storage at 4°C and 28°C were detected, nevertheless there was no statistical difference between fatty acids composition in yolks from both treatments. The study indicated that storage temperature had effect on fatty acids profiles of egg yolks from diets without and with soapstock and this effect was not related to dietary soybean soapstock.
Session 67D, Food Chemistry: Lipid and carbohydrate chemistry
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