Quality of dairy milk obtained from automated dispensing machines in Nairobi County, Kenya

Abstract

Dairy milk is one of the most widely consumed food products. Owing to its rich nutritional value, milk acts as a good medium for microbial growth. Suppliers have been known to adulterate milk with various chemicals for preservation, increasing viscosity and whitening, among other reasons. Increasingly, residents of big cities such as Nairobi County are purchasing their milk from automated milk dispensing machines, which obtain milk from small scale dairy farmers. This study set out to determine the quality of milk purchased from automated milk dispensing machines in selected settlements in Nairobi County. Microbial quality was determined using the methylene blue reduction test while established chemical methods were employed in the tests for hydrogen peroxide and formaldehyde. Twenty one samples, representing 70% of the samples analyzed, tested positive for hydrogen peroxide while only 5 (16.7%) and 7 (23.3%) samples tested positive for formaldehyde and microbial contamination, respectively. These results indicate that there is need to improve the quality of milk dispensed in automated dispensing machines.

Keywords: Milk, adulteration, formaldehyde, hydrogen peroxide