EFFECT OF PROCESSING TECHNIQUES ON THE MICROBIOLOGICAL AND PCCC CCC C IPEKERE’).

Abstract

Maize cake, ‘ipekere’ is a food product of maize; two different varieties of maize namely, white and yellow maize were used. It is produced by washing and grinding the fresh maize kernels into a thick paste, in reducing into thick three different techniques were employed which are machine-grinding, hand-grinding and blending; some of the paste were fried immediately, while the remaining were allowed for fermentation before frying with palm oil. The number and type of microorganisms per ml. of the fermenting substrates were characterized using conventional methods. Fungi isolated from the maize pastes were Aspergillus niger, Aspergillus flavus, Neurospora crassa, Sacchromyces cerevisiae and Candida stellata. The bacteria isolated were Bacillus subtilis, Lactobacillus fermentum and Staphylococcus aureus. During fermentation, the microorganisms had been reduced to Lactobacillus fermentum and Sacchromyces cerevisiae. Total viable bacteria counts during fermentation ranged from 1.0X104 to 7.5X105 cfu/ml while the fungal counts during the fermentation ranged from 2.4X104 to 7.2X105 sfu/ml. Fermentation caused a general decrease in pH from 4.65 to 3.00 and an increase in titrable acidity from 0.015 to 0.163 after 7 days fermentation. There was an increase in the crude protein, ash, moisture and fat content while reduction in the carbohydrate and crude fibre content during fermentation. Magnesium, iron, zinc, calcium and manganese content increased during fermentation; the maize samples that were subjected to machine grinding had higher mineral contents compared to other processing techniques: this might be due to the better surface area provided by this technique which might have enhance the action of fermentation organisms. Analysis on antinutrients showed a considerable reduction in the level of phytate during fermentation but a slight increase in the tannin level also during fermentation. Antioxidant value for the assay of 1, 1- diphenyl- 2- picryl hydrazyl (DPPH) free radicals scavenging activity reduced during fermentation with Hand- grinded white and yellow maize (WH and YH) as the highest, having values of 69.44 and 65.54 respectively on day 0 and a value as low as 18.30 for machine grinded, white maize (WM) on day 7 of fermentation. Overall acceptability for all the samples ranked with their organoleptic properties showed that all the samples were accepted when based on a 5 point scale (with 5= highly acceptable and 1 = highly unacceptable). Machine grinding was the best processing techniques that produced the best quality maize cake (Ipekere).