INHIBITORY SUBSTANCES PRODUCED BY PROBIOTIC BACTERIA FOR CONTROL OF FOOD-BORNE PATHOGENIC AND SPOILAGE MICROORGANISMS IN DIPS

Inhibitory substances produced by probiotic bacteria for control of DEDICATION I dedicate this thesis to m y parents who have always believed in m e and generously supported m e in all m y efforts. A B S T R A C T The success in using a food product as a delivery vehicle for probiotics depends on its ability to maintain required level of viable cells (at least 107 cfu g"1) and to suppress the growth of spoilage and pathogenic organism. Cheese-based dips could delivery probiotic bacteria owing to its stable pH, buffering capacity of ingredients and the presence of prebiotics. The anti-microbial properties of probiotics can also be employed for controlling the spoilage organisms such as yeast and mould. The work described in this thesis focused on the survival of probiotics and their anti-microbial effects in dips. Effective selective enumeration methods wer