Valuing the Antigenicity of Sheep Milk Proteins after Fermentation at 40oC

The main objective of this work is to show a fermentation influence by some associations of two lactic acid bacteria and three bifidobacteria on proteolysis and the antigenicity of sheep milk proteins. This latter freshly collected is skimmed, sterilized and inoculated by a mixed culture. The mixture is homogenized and incubated at 40°C until it is a curd. On these fermented milks previously lyophilized, were measured the rate of lactic acid product, bacterial counts, the rate of total protein, α-NH2 functions and the antigenicity of three proteins (β-Lg, α-La and SA). The obtained averages are compared with the "t" test of Student compared to sterile milk without ferment taken as control. The best proteolysis is achieved in the fermented milk by Streptococcus thermophilus (St) associated with Lactobacillus plantarum (Lp) with a high antigenic potential of β-Lg and the α-La probably due to the detection of unmasked antigenic sites.