Spoilage potential of psychrotrophic bacteria isolated from raw milk and the thermo-stability of their enzymes

Lei, Yuan, Sadiq, Faizan Ahmed ORCID: https://orcid.org/0000-0003-1596-4155, Liu, Tong-jie, Li, Yang, Gu, Jing-si, Yang, Huan-yi and He, Guo-qing 2018. Spoilage potential of psychrotrophic bacteria isolated from raw milk and the thermo-stability of their enzymes. Journal of Zheijang University SCIENCE B - Biomedicine & Biotechnology 19 , pp. 630-642. 10.1631/jzus.b1700352

Full text not available from this repository.

Abstract

The storage and transportation of raw milk at low temperatures promote the growth of psychrotrophic bacteria and the production of thermo-stable enzymes, which pose great threats to the quality and shelf-life of dairy products. Though many studies have been carried out on the spoilage potential of psychrotrophic bacteria and the thermo-stabilities of the enzymes they produce, further detailed studies are needed to devise an effective strategy to avoid dairy spoilage. The purpose of this study was to explore the spoilage potential of psychrotrophic bacteria from Chinese raw milk samples at both room temperature (28 °C) and refrigerated temperature (7 °C). Species of Yersinia, Pseudomonas, Serratia, and Chryseobacterium showed high proteolytic activity. The highest proteolytic activity was shown by Yersinia intermedia followed by Pseudomonas fluorescens (d). Lipolytic activity was high in isolates of Acinetobacter, and the highest in Acinetobacter guillouiae. Certain isolates showed positive β-galactosidase and phospholipase activity. Strains belonging to the same species sometimes showed markedly different phenotypic characteristics. Proteases and lipases produced by psychrotrophic bacteria retained activity after heat treatment at 70, 80, or 90 °C, and proteases appeared to be more heat-stable than lipases. For these reasons, thermo-stable spoilage enzymes produced by a high number of psychrotrophic bacterial isolates from raw milk are of major concern to the dairy industry. The results of this study provide valuable data about the spoilage potential of bacterial strains in raw milk and the thermal resistance of the enzymes they produce.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Dentistry
Publisher:	Springer
ISSN:	1862-1783
Last Modified:	03 May 2024 11:30
URI:	https://orca.cardiff.ac.uk/id/eprint/168630

Actions (repository staff only)

Edit Item