Effect of nisin on the viability of Staphylococcus aureus in kareish cheese

Abstract

Staphylococcus aureus is a common cause of food-borne disease worldwide and food poisoning. This study reports the effect of nisin (0, 10 and 12.5 ppm) against Staphylococcus aureus in manufactured kareish cheese. Nisin was effective in reducing S. aureus count in cheese; a reduction of S. aureus count was observed from the 2nd day of storage period. S. aureus in kareish cheese decreased gradually from 4x108 to (8×107, 6.5×107, 5.8×107 CFU/gm.) in the 1st week till reached at the end of storage period of the 4th week to (4 ×104, 1.1×103, 1×102 CFU/gm.) for cheese containing (0, 10 and 12.5 ppm) of nisin, respectively during manufacture and storage for a month in the refrigerator at 4 ˚C. The data obtained in this study suggested that the use of nisin-containing cheese can be an effective method of controlling the growth and multiplication of S. aureus in cheese.