Effect of time, temperature and humidity on biodeterioration of corn cake snack

Food spoilage microorganisms representing 5, 6 and 10 genera of moulds, yeasts and bacteria, respectively were isolated from corn cake snack. Each of the samples analysed had initial pH value favourable to microbial growth and activities while only 28% had spoilage-enhancing moisture contents (> 13%). The effect of temperature and relative humidity (RH) on biodeterioration during a 24-day storage period was determined by monitoring changes in the pH and total microbial colony counts. Whereas very little or no deterioration was recorded for samples contained in 51% and 71% RH chambers at 30 and 45 degrees C, substantial deterioration was obtained at the same temperatures under 89.5% and 100% RH. At 15 degrees C, very little or no deterioration was detected except under 79.5%, 89.5% and 100% RH when slight spoilage changes were recorded as from the 12th or 18th day. The overall results show that the obtained colony counts and pH values monitor spoilage equally.