Composição e características físico-químicas do leite instável não ácido (LINA) na região de Casa Branca, Estado de São Paulo / Composition and physical-chemical characteristics of unstable non-acid milk in the region of Casa Branca - São Paulo State

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The aim of this study was to determinate the composition and the physical-chemical characteristics (pH, acidity, alcohol stability, total solids, fat, lactose, non fat solids and total protein), somatic cells counts (SCC) and casein fractions (α-S1, α-S2, β and κ) of unstable non-acid and stable milks at the alcohol test at 78% (v/v). Samples were collected from all the dairy farms that provide milk to a dairy plant located in Casa Branca - São Paulo State. Sampling procedures were done on March, May, July and September 2007. Milk samples from each dairy farm presenting instability to alcohol test at 72% (v/v) and acidity less than 18ºD were considered as unstable non-acid milk. From the total of unstable samples to alcohol test at 72% (v/v), 64.77% were identified as unstable non-acid milk. The frequency of unstable non-acid milk samples varied according the month of sampling, hence indicating a possible seasonal influence on the occurrence of this problem in the dairy herds studied. On July, the incidence of unstable non-acid milk was higher, coinciding with the dry season, when the quality and availability of forage are reduced. On September, at rainfall season, when the availability and quality of forage are better, the incidence of unstable non-acid milk decreased. There was a significant increase in the levels of fat, lactose and SSC in samples collected on July, although a significant decrease was observed in the concentrations of total protein. In this month, a lower concentration of κ-casein was also noted in unstable non-acid milks. However, the differences between the α-S1, α-S2, β and κ casein of unstable non-acid milk and stable milk were not significant in all sampling months. Results showed that the occurrence of unstable non-acid milk is common in dairy herds in the studied area, which can cause significant losses to the dairy industry and dairy farms due to the discharging of milk.

ASSUNTO(S)

casein fractions análises físico-químicas casein stability lina estabilidade da caseína physical -chemical analyses cromatografia unstable non-acid milk chromatography frações de caseína

ACESSO AO ARTIGO

Documentos Relacionados