Enzymic differentiation between curds of heated and raw milk II. Milk peroxidase

✍ Scribed by K. C. Guha; B. R. Roy

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 290 KB
• Volume: 24
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/jsfa.2740240102

✦ Synopsis

Abstract

Unlike phosphatase, peroxidase, once destroyed by heating of milk, is not regenerated by the acidity or microbial growth of curd formation or by reasonable ageing. This reveals that curd‐forming micro‐organisms do not have or form peroxidase. The test was repeated in various heating conditions of milk. Peroxidase is destroyed even when the temperature of milk is gradually raised to 80 °C (in 3 min). Less‐heated milk, e.g. pasteurised milk and its corresponding curd, retain this enzyme. A positive test in the curd of raw milk is not affected by reasonable ageing or increased acidity but by excessive fermentation (secondary fermentation or putrefaction) which again can be halted by addition of formalin. The peroxidase test, therefore, appears to be a test for differentiating curds of heated and unheated milk.