Microbial profile in flour milling process: Yeast and Moulds analysis / Siti Nurul Fitriah Ahmad

A survey was undertaken to determine the mycological status of the wheat flour and the distribution of mycological in the flour milling fractions and end products. A total of 8 milling stages and end products was obtained from a flour mill factory in Klang. Yeast is 10 4Cfu/ml , with 43.13 % of 51 plates of the total plates tested. Mould is in the range of 103 to 104 Cfu/ml, with 31.9 % of plates of the total plates tested. The mode for yeast and mould was 103 and 104 respectively. The common mould growth observed were aureobasidium, aspergillus, cladosporium spp, penicillium, Rhizopus spp. In milling operations, water can encourage mycological growth in residue on mill machinery. Mycological count are higher after conditioning. The percentage of positive plates for the presence of yeast and mould was 17.4 % and 17. 6 % respectively. Yeasts showed a low count in early incoming wheat. After first break stage the count started to increase from 103 to 104 until it is reached the higher level of 6.0 x10 4 Cfu/ml in wheat germ and 1.1 x10 4 Cfu/ml in bran end products. As wheat layers are separated, surface- adhering contaminants are concentrated in end products bran and wheat germ, which comprise the outer layer of the grain. Consequently, the inner endosperm fractions contain lower mycological counts and flour is the cleanest end products of the milling process. Generally flour mycological, is one of the factors that reduce the quality of the product, and high-quality flour products requires the implementation of a thorough, well-planned cleaning and sanitizing program aimed at controlling and/or reducing the amount of microbiological entering products during and after processing/preparation.