Lactococcus species for conventional Karish cheese conservation

Abstract Karish cheese is one of the most popular, oldest cheese varieties in Egypt and Arab countries. As a low fat cheese; it is a promising food in particularly for old people and whom suffering from obesity related diseases. The objective of this work was to isolate, identify and select Lactococcus lactic acid bacteria (LAB) from traditional Karish cheese to conserve and enhance the characteristics of conventional Karish cheese made of pasteurized milk to meet the new regulations for dairy production. Two Lactococcus strains were selected out of 11 Lactococcus LAB isolates from 15 Karish cheese samples, phenotypically and technologically characterized then identified using genotypic 16S rRNA approach. The two unique strains; L. lactis subsp cremoris ( KM746 ) and the exopolysaccharide (EPS) producing strain L. lactis subsp lactis ( KM721 ) were applied as single starter cultures in comparison with commercial starter culture used in Karish cheese making. Selected LAB showed decent growth throughout processing and storage at 4 °C for 10 days preventing growth of coliform and staphylococci. Chemical composition of tested cheese samples was similar to the conventional Karish cheese, whilst rheological and sensorial properties were enhanced which encourage recommending these strains as starter cultures conserving and enhancing this type of traditional cheese.