Characterization of moulds associated with spoilage of bread soldin Ilaro, Yewa-South, Nigeria

Abstract

Bread is an important staple food; however, it is highly susceptible to microbial spoilage due to post-production contamination and improper storage. This study aimed at determining moulds associated with bread spoilage and their hydrolytic activities. Fifteen (15) brands of bread were sampled and moulds that are responsible for their spoilage were isolated using spread plate technique. The isolates were identified on the basis of colonial and microscopic characteristics. Characterization of the moulds was on the basis of their hydrolytic activities. The mould counts of the bread ranged from 1.0 x 104 cfu/g to 7.7 x 106 cfu/g. The highest count was recorded in sample JB and the least count was in sample PB. The moulds associated with spoilage of the bread samples were; Aspergillus niger, Aspergillus flavus, Mucor sp., Rhizopus sp., and Penicillium sp. The predominant organism was Aspergillus niger. The moulds showed varying degrees of hydrolytic activities on milk, starch and olive oil agar media. On the basis of their hydrolytic activities, all the moulds played vital roles in the spoilage of bread. Bread, a ready-to-eat food could be a source of food-related illnesses due to moulds associated with its spoilage.