Banca de DEFESA: JOAO BAPTISTA GONDIM DE ARAUJO

Influence of Kappa Casein polymorphism on the composition and incidence of instable non-acid milk (LINA), in milk samples submitted to alcohol test at various concentrations.

Lina, Alcohol test, Polymorphism, Kappa-casein, CCS.

Bovine milk is a food of high nutritional and economic importance for humans. The dairy market has been looking for more and more good quality raw material that generates a good yield and without causing problems in the industrial process.  Milk samples were collected at Fazenda São Miguel located in the municipality of São Gonçalo do Amarante Estado do Rio Grande do Norte using the Free Stall system, and with the Jersey herd genotyped for beta and kappa casein and selected for beta casein variant A2A2. A total of 127 samples were collected and titratable acidity, SCC, centesimal composition, and alcohol stability were analyzed at concentrations of 72°, 74° and 78°. In the experiment, no influence of kappa casein polymorphism was observed for protein, fat, lactose, total solids and solid extract without fats. No significant correlation of SCC was observed with the other components studied. However, there were significant differences at various levels between the other components, the high correlations with fat with ST, Protein with Lactose, ST,SNG were highlighted by the high correlations with Fat with ST, Protein with Lactose, ST,SNG; Lactose with ST , SNG The influence of kappa-casein polymorphism on milk stability was not observed. No influence of somatic cell count was observed with the incidence of LINA.  No effect of Kappa-casein polymorphisms was observed in SCC.