Microbiological Qualities of Hawked Retted Cassava Fufu in Aba Metropolis of Abia State

ABSTRACTRetted cassava fufu samples obtained from five local government areas in Aba Metropolis were analyzed. Their microbial counts, chemical and organoleptic properties were determined from the day of preparation and every day for the eight days of hawking. There were increases in the microbial counts from initial average of 2.02×105cfu/g on the zero day to an average counts of 18.70×105cfu/g on the eighth-day. The microorganisms associated with spoilage were found to be Bacillus cereus, Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus spp. The chemical qualities as determined on the freshly prepared fufu samples from all the local government areas were comparable. The colour, odour and texture of the freshly prepared samples were acceptable and rated high by the panelists. It was observed that as the days of hawking of the fufu samples increased, the organoleptic qualities decreased. The pH increased from an average of 3.85 on the zero day to 4.25 average on the eighth day. The titratable acidity decreased from 1.14% on the zero day to 0.94% on the eighth day. The results are discussed in relation to the public health implications of hawked retted cassava fufu

Yield of ethanol from enzyme-hydrolyzed yam (Dioscorea rotundata) and cocoyam (Xanthosoma sagittifolium) flours

Fresh whole yam tubers and cocoyam corms were separately processed into flours by washing, peeling, blanching, slicing,drying and milling. The flours were enzyme-hydrolyzed by mixing 500g of flour with 2Lof water followed by treatment with a combination of bacterial alpha amylase, limit dextrinase and fungal alpha amylase and heating to 92 o C at pH 6.30. The hydrolysis process was maintained until iodine test for starch was negative. The hydrolyzed slurry was cooled to 20 o C and yeast was inoculated. The slurry was allowed to ferment for 5 days during which the pH, specific gravity (sg), total titratable acidity (TTA), and % sugar content were respectively measured. The yield of dry chips and flour (30.6% and 25.3% respectively) were about half of the yield for same items from cocoyams (64.1% and 54.2%). The sugar content (for yam/cocoyam slurries) decreased from 19.05/16.8%wt (on day 1) to 1.72/1.58%wt (on day 5), the ethanol content increased from 0%wt/vol on day 1 to 5 / 4.99%wt/vol on day 5. The acid produced by fermentation reduced the pH from 5.80 to 4.01 and 5.82 to 4.20 for the yam and cocoyam slurries respectively on day 5. The correlaton coefficient of the regressed sg vs TTA data was -1, sg vs ethanol content was -1 and sugar vs ethanol was -1 for both media. The yield of flour from yam was 25.4% and 54.2% for cocoyam. The yield of ethanol from the 500g of flour was 130g for yam and 117g for cocoyam. Raw cocoyams offer a greater potential for flour and ethanol production than yam

Antinutrients, micronutrients and glycemic characteristics of rice bran enriched with yam flour

This study investigated the antinutrients, micronutrients and glycemic characteristics of yam flour enriched with rice bran particles at the ratios of 100:0, 95:5, 90:10, 85:15, 80:20 and 0:100 of yam flour: rice bran particles. The flour samples were subjected to antinutrients, minerals and vitamins analyses. The glycemic characteristics of the six flour samples were measured by feeding six out of the seven groups of albino rats with respective six flours and the seventh group was fed with reference feed, white bread. The percentage weights gain for all the rat groups ranged from 2.1 to 36.0%. The antinutrients decreased with increase in the ratio of rice bran particles in the flours and their ranges were: flavonoids 0.2-0.71mg/100g, alkaloids 0.17-1.09mg/100g, tannins 0.22-0.44mg/100g and phenols 0.36-0.56mg/100g. The minerals (calcium, magnesium, potassium and phosphorus) and B-vitamins (riboflavin, thiamin and niacin) of the flours increased with increase in the ratio of rice bran particles. However, there was decrease in the level of vitamin C with increased ratios of rice bran particles in the flours. The glycemic response range was 60.29 to 206.69mg/dl and it was observed to reduce as the ratio of rice bran particles increased. The T-test showed there was a relationship between the dietary fibre and blood serum glucose, but the relationship was not significant. This study showed that the yam flours that were substituted with ≥15% rice bran particles had lower levels of antinutrients, higher micronutrients and lower glycemic characteristics.Keywords: Nutrients, blood glucose, glycemic response, dietary fibr