Influence of two commercially available bifidobacteria cultures on Cheddar cheese quality

Two Cheddar cheeses were manufactured at pilot scale, each inoculated with a different strain of commercial probiotic bifidobacteria in an effort to develop probiotic Cheddar cheese harbouring high numbers of viable Bifidobacterium sp. The bifidobacteria strains were introduced during Cheddar manufacture 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 10(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 addition 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 Cheddar cheese. During early ripening, more extensive protcolysis and improved flavour were observed in the B. lactis Bb-12 cheese compared with the control cheese. Quantitative differences in volatile compounds were observed in the cheeses harbouring bifidobacteria, most notably acetic acid in the B. lactis 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.