FLAVOR ENHANCEMENT OF DIRECT ACIDIFIED KAREISH CHEESE USING ATTENUATED LACTIC-ACID BACTERIA

Eight batches of Kareish cheese were made by direct acidification to s tudy the effect of adding heat-or freeze-shocked Lactobacillus delbrue ckii sp. bulgaricus or Streptococcus salivarius sp. thermophilus alone or along with freeze-shocked Lactococcus diacetylactis on the cheese quality. This cheese was compared with the best cheese obtained in the first part of study, which was made by adding sodium citrate and free ze-shocked Lactococcus diacetylactis. Addition of attenuated Lactobaci llus delbrueckii sp. bulgaricus alone or combined with Lactococcus dia cetylactis caused a significant (p less than or equal to 0.05) increas e in soluble nitrogen (SN), soluble tyrosine (STY) and soluble tryptop han (STR), while it caused significant (p less than or equal to 0.05) decrease in total volatile fatty acids (TVFA) and cheese scores. Chees e made with combination of Lactobacillus bulgaricus and Lactococcus di acetylactis had lower SN, STY and STR, while it had higher TVFA and ch eese scores than the corresponding cheese made with Lactobacillus bulg aricus alone. Addition of freeze-shocked Streptococcus salivarius sp. thermophilus alone increased SN, STY and STR, while decreasing TVFA an d cheese scores of the resultant cheese. Adding of Lactococcus diactyl actis along with Streptococcus salivarius sp. thermophilus caused a si gnificant increase in SN, STY, STR, TVFA and cheese scores compared wi th cheese made with Streptococcus salivarius sp. thermophilus alone. C heese made with either freeze-or heat-shocked Streptococcus salivarius sp. thermophilus and freeze-shocked Lactococcus diactylactis were the most acceptable cheese. Pickling period could be shortened by 33% wit hout determinant effect on cheese quality or acceptability. (C) 1997 C anadian Institute of Food Science and Technology. Published by Elsevie r Science Ltd.