USING LOCAL ISOLATES OF Lactococcus lactis subsp. lactis AND Lac. Lactis subsp. cremoris AS STARTERS IN CHEDDAR CHEESE PROCCESING

Abstract

Lactococcus. lactis subsp lactis and Lactococcus. lactis subsp. cremoris were isolated and identified from soft white cheese and Medford cheese. The isolates grow within a temperature range of 10-45 C and sodium chloride concentration up to 5%. Lac. lactis subsp. lactis resisted pasteurization (63 C for 30 min) and a heat treatment at 65 C for 15 min. Lac.lactis subsp. cremoris could grow at a sugar concentration up to 25% .The two isolates (1:1) were used as a starter for Cheddar cheese making at a percentage of 0.5% which proved a high efficiency that was noticed from fast developed acidity and no bitterness in ripened cheese, even though, they showed high photolytic activity that helped accelerating cheese ripening