Production of hard cheese from caprine milk by the use of two types of probiotic cultures as adjuncts

Abstract

Hard cheeses (Kefalotyri‐like) were manufactured from caprine milk with yoghurt as a starter (A), and with its partial replacement with the probiotic adjuncts Lactobacillus rhamnosus LC 705 (B) and/or Lactobacillus paracasei ssp. paracasei DC 412 (C). Both adjuncts retarded the growth of enterococci, and the environment in cheese B did not favour the recovery of lactic acid bacteria (LAB) on Rogosa agar. However, better recovery of the LAB population on M17 agar from cheeses B and C made with adjuncts was recorded early in ripening, and this was accompanied by a greater decrease in pH. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) of whole‐cell protein demonstrated that cheese C, made with Lb. paracasei ssp. paracasei as adjunct, is a better vehicle for delivery of live probiotic cells (10 7 cfu/g) to the gastrointestinal tract than cheese B, made with Lb. rhamnosus ; the latter did not belong to the predominant microflora of one out of the two B cheeses. Urea‐PAGE electrophoresis results indicated that adjunct lactobacilli enhanced the degradation of both α S ‐casein (α S ‐CN) and β‐casein (β‐CN). In the fresh cheese, hydrolysis of α S ‐CN was more rapid than β‐CN, and the free amino acid content of B and C was higher than in A. Lipolysis products were also higher in B and C than in A as ripening progressed, and the organoleptic characteristics of these cheeses resulted in higher scores, in the order C > B > A. Thus, making Kefalotyri‐like cheese from caprine milk with probiotic lactobacilli, particularly Lb. paracasei ssp. paracasei, as adjunct can be considered an effective way of producing a cheese with a large number of probiotic cells.