Effect of thermization of dahi on post fermentation acidification during refrigerated storage

Post fermentation acidification is defined as the development of acidity past the desired level of fermentation or acid development. Effect of thermization at 65oC for different periods (30 sec, 60 sec, 2 min and 5 min) on post fermentation acidification of dahi samples prepared using Lacticaseibacillus rhamnosus 18 or Lacticaseibacillus casei 01 upon refrigerated storage was assessed in this study. Significant changes (p< 0.01) were observed between the two starter cultures in terms of their post acidification potential with L. rhamnosus 18 dahi showing lower pH, higher titratable acidity and lactobacilli count than L. casei 01 during refrigerated storage. On assessing the impact of heat treatment on post acidification, significant decrease (p< 0.05) in pH, increase (p< 0.01) in titratable acidity and lactobacilli count of the heat treated and control samples were observed throughout the storage. Based on this study, it can be inferred that heat treatment at 65oC for even upto 5 min is not having any significant inhibitory effect on post fermentation acidification characteristics of the lactobacilli cultures tested

Ozone: A Potent Disinfectant for Application in Food Industry -An Overview

504-509With the emergence of new microbial strains like Listeria, virulent E. coli, assorted viruses and accumulation of toxic chemicals in environment increased attention has been given to the safe use of sanitizers, bleaching agents, pesticides, etc., in industrial processing. The food industry, in particular, is in search of disinfectants that are effective against pathogens and are safe to use in specific applications. Ozone (O3), is effective against majority of microorganisms tested and its applications in the food industry are related to decontamination of product surface and water treatment. Ozone has been used with success to inactivate contaminant micro flora on meat, fruits, vegetables, and dry foods. Excessive use of ozone, however, may cause oxidation of some ingredients on food surface. Additional research is needed to optimize its use in food applications. The paper reviews the various aspects of ozone as a disinfectant for different applications in food industry