Physicochemical and Microbiological Properties of Powdered Milk Brands Sold in Awka, Anambra State, Nigeria

Abstract

This study was conducted to compare the physicochemical and the microbiological properties of powdered milk samples packaged in sachets and big paper bags, otherwise known as “industrial milk”, from Eke-Awka market, Anambra State, Nigeria. Nine samples of three different products were purchased from the market. Their physicochemical properties were obtained by testing for protein, acidity and milk solid non-fat (MSNF), ash content (AC), vitamin A, fat content (FC), melamine, reducing sugar (RS), total inverted sugar (TIS), and moisture content (MC) using standard methods. The microbiological quality of the samples was assessed by preparing a tenfold serial dilutions of the samples and appropriate dilutions inoculated onto appropriate growth media. The physicochemical properties showed that the sachet had lower acidity, MC, AC, RS and higher protein, FC, MSNF, TIS and acceptable vitamin A levels than the industrial milk. While some of the sachet samples contained Staphylococcus aureus, Bacillus cereus, Shigella sp and Penicillium
sp, most of the industrial milk contained in addition to the above, Enterobacter aerogenes, Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa, Geotrichum candidum and Aspergillus niger. Sachet powdered milk is a better option than the industrial milk as they have favourable physicochemical properties and lower microbial load. However, adequate care should be taken and proper hygiene followed in the manufacture and sale of these powdered milk.

Keywords: Protein, acidity, moisture content, microbial load.