Ocorrência de leite com instabilidade da caseína em Santa Vitória do Palmar, RS Occurrence of milk with casein instability in Santa Vitória do Palmar, RS

, ** Resumo O objetivo do presente trabalho foi determinar a ocorrencia de leite com instabilidade da caseina no extremo sul do Brasil. Duzentas e oitenta e duas amostras de leite cru foram coletadas em estabelecimentos produtores de leite do municipio de Santa Vitoria do Palmar, Rio Grande do Sul (RS). As amostras foram analisadas pelo teste do alcool etilico a 70% (v/v), acidez titulavel e contagem de celulas somaticas (CCS). Leites com resultado positivo no teste do alcool, CCS menor que 1,8 x 10 6 Abstract The aim of the present work was to determine the occurrence of milk with casein instability in the extreme south of Brazil. Two hundred and eighty two samples of raw milk were collected from dairy farms in district of Santa Vitoria do Palmar, Rio Grande do Sul (RS). The samples were analyzed by alcohol 70% (v/v) test, titrable acidity, and somatic cell count (SCC). Milk with positive result for alcohol test, SCC lesser than 1.8 x 10 6 cells/mL and acidy until 18oD were considered as milk with casein instability. Among the samples without acquired acidity and without SCC enough for changing the casein stability, 33.93% showed positive results for the alcohol test. The highest and the lowest occurrence of milk with casein instability were found in autumn (49.25%) and in summer (19.05%), respectively. The results highlight the importance of the search of milk with casein instability, quantifying it and making data available for evaluation of the economic impact of the problem in the studied region.