Influence of two commercially available bifidobacteria cultures on Cheddarcheese quality

Two Cheddar cheeses were manufactured at pilot scale, each inoculated with a different strain of commercial probiotic bifidobacteria in an effort to d evelop probiotic Cheddar cheese harbouring high numbers of viable Bifidobac terium sp. The bifidobacteria strains were introduced during Cheddar manufa cture as starter adjuncts at levels of 9.9 x 10(7) cfu mL(-1) of cheesemilk for bifidobacterium lactis Bb-12 and 9.2 x 10(6) cfu mL(-1) for B. longum BB536. B. lactis Bb-12 survived at high numbers (greater than or equal to 1 0(8) cfu g(-1) cheese), while numbers of B. longum BB536 were reduced to 10 (5) cfu g(-1) cheese, following six months of ripening. The addition of B. longum BB536 did not adversely affect cheese composition, while the additio n of B. lactis Bb-12 had a partial negative effect, resulting in a moisture level of 40%, which is slightly above the legal limit permitted for Chedda r cheese. During early ripening, more extensive protcolysis and improved fl avour were observed in the B. lactis Bb-12 cheese compared with the control cheese. Quantitative differences in volatile compounds were observed in th e cheeses harbouring bifidobacteria, most notably acetic acid in the B. lac tis Bb-12 cheese. This study illustrates the suitability of Cheddar cheese as a probiotic functional food harbouring certain bifidobacteria strains. ( C) 2001 Elsevier Science Ltd. All rights reserved.