Unveiling the significance of psychrotrophic bacteria in milk and milk product spoilage – A review
Shreya Saha, Reshab Majumder, Pavel Rout, Shamim Hossain
Abstract
Since ancient times, milk and milk products have been a natural part of life. Milk can be referred to as the carrier of pathogenic and spoilage-causing microbes due to its high nutritional content. Raw milk is cooled as soon as it is collected in order to preserve its quality. Cooling retards microbial spoilage but on the other hands, it creates the favourable growth environment for potential psychrotrophs in milk system. These microbial populations are able to secrete several proteases and lipases, which are highly heat stable and can not be degraded by means of pasteurization. Several psychrotrophs including Pseudomonas sp, Bacillus sp. etc have the potential to secret exopolysaccharides, which has further role to create biofilm across the milk contact surfaces. So, it is essential to prevent microbial association in food system so that quality and safety of milk remain intact. This paper deals with an overview of different psychrotrophic bacterial action in milk and products, sources of contamination, cause of spoilage and its preventive measures.