Detection of bacterial spoilage in some fruit flavoured ultra-high temperature milks in Nigeria

Abstract

Statistical analyses of pH measurements and microbiological methods have been employed to monitor microbial activity (spoilage) in a brand of non-refrigerated mango and vanilla flavoured ultra-high temperature (UHP) milk drinks in Nigeria. The mango flavoured milks were more sensitive to changes in storage conditions than was the vanilla flavoured milks. The aerobic bacterial flora in the spoiled flavoured milks was dominated by Gram-positive cocci, both catalase-positive and catalase-negative types. Coliforms and pseudomonads were also detected. The importance of this study to the methods for detecting spoilage in quality control and to the storage conditions of such products in the tropics is discussed.