14A-49 |
Fatty acid composition of raw cow’s milk during lactation in tropical areas of Mexico |
V. PARDIO1, L. Landín1, I. Gómez1, G. Pérez1, K. Waliszewski2, 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 Cow’s milk is of great economic importance for Mexico due to the consumption of a variety of products, particularly cheese. Fatty acid (FA) content of milk fat is subjected to variations due to differences in the stage of lactation, season, parity of cows, and animal nutrition, which affect properties during milk processing. The aim of the study was to determine FA of bovine milk fat during eight months period to evaluate the effect of lactation in fat composition. A total of 320 cow’s milk samples from four dairy farms located in Veracruz state, Mexico, were collected at random from 10 animals, during 240 days. The groups were balanced for parity and for the genetic index. Analysis of the fatty acid composition was carried out by GLC 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 fatty acids C18:3 and C22:5 were significantly higher and C14:1 lower during the early lactation period. The C12:0, C14:0, and C16:0 were significantly higher and C10:0, C16:1, C20:4 were significantly lower in the middle and late lactation periods, and C22:6 was not detected during the late lactation period. The higher the concentration of FA in the milk fat was, the higher the concentration of C18:2 and C18:3 was detected. The most abundant fatty acids were C16:0 followed by C18:1, C18:0 and C14:0. A high ratio of 18:1/18:0 in milk fat could lower the melting point of the fat, indicating that milk fat could not be adequate for producing cheeses for grating. The high contents of 18:2 could produce oxidized flavors in some milk products. Thus, the composition of milk fat should be changed to accomplish specific manufacturing purposes.
Session 14A, Dairy Foods: General developments in dairy technology I
|