beneficial effect of using starter cultures to inhibit outgrowth of spoilage organisms in kareish cheese during storage

The antagonistic effect of S. lactis [Lactococcus lactis subsp diacetylactis], S .thermophilus [S. salivarius subsp thermophilus] and L. bulgaricus [L. delbruckii subsp. bulgaricus] strains against E. coli, Ent. aerogenes, Ps. fluorescens and Sacch. cerevisiae was studied on a laboratory scale in skim milk or in contaminated and respectively uncontaminated kareish cheese In skim milk L. bulgaricus was the most effective culture in suppressing the growth of the spoilage microorganisms investigated, followed by S. lactis subsp diacetylactis, S.thermophilus and lastly S. lactis which showed the least suppressing effect. Ps. fluorescens and Ent. aerogenes were most sensitive to all tested starter cultures followed by E. coli and Sacch cerevisiae. In contaminated kareish cheese Sacch cerevisiae and S. lactis were not included due to minimal effect in skim milk experiments Ent, aero genes was generally the most sensitive spoilage organism followed by Ps. fluorescens while E. coli was the least affected by the starters investigated. L. bulgaricus was the most effective strain against Ent. aero genes followed by S. lactis subsp diacetylactis and S. thermophilus in a descending order. S, lactis subsp diacetylactis was the most effective strain against Ps. fluorescens and E. coli followed by L. bulgaricus and S. thermophilus in descending order. In uncontaminated kareish cheese the psychrotrophs were generally more sensitive to the various starters used than the coli forms L. bulgaricus and S. lactis subsp diacetylactis were most suppressive

Ras cheese manufacture from buffaloes milk using different renneting systems

Buffalo's milk was made into cheese and served as a control [T1]. It was compared to aging of milk at 2+/- 0.1C for 24 hr with half the amount or rennet [T2] and treatment with enzyme mixture of Neutrase L + Piccantase# A before renneting [T3]. Results indicated that titratable acidity [TA], soluble protein coefficient and free amino acids were higher in T3 than the other two treatments. These results were confirmed by electrophoretic patterns. For amino acids glutamic acid as responsible for good flavour increased during ripening and was higher in T3 than in T1 and T2 while arginine which is responsible for abnormal flavor decreased during ripening. Also the total free volatile fatty acids [TFVFA] was higher in T3 than in T1 and T2 during ripening. No big differences were observed between T1 and T2 in most of the parameters measured. Organoleptically, Ras cheese manufactured from buffalo's milk treated with enzyme mixture was more preferable and therefore was recommended for manufacturing Ras cheese from buffalo's milk