Extension of shelf life of garri by hygienic handling and sodium benzoate treatment

The effect of hygienic handling and sodium benzoate treatment on the microbial, quality and shelf stability of garri was evaluated for 14 month using standard methods. Results indicated that there were less bacteria and fungi in the hygienically handled garri at the end of the storage period than for conventionally handled samples. No growth was detected in the hygienically handled and sodium benzoate (SB) treated samples. Six bacteria and nine fungi genera were isolated from the conventionally processed and hygienically handled garri, respectively. Only Bacillus was isolated from the SB treated samples. The degree of deterioration recorded in the protein, lipid, ash and available carbohydrate for the conventionally handled samples were significantly more than the hygienically handled and SB treated samples. Overall sensory evaluation shows that combination of hygienic handling and SB treatment has maximum positive impact on the microbial quality, shelf stability and acceptability of garri during storage.African Journal of Biotechnology Vol. 4 (7), pp. 744-748, 200

Antimicrobial Effects of Sodium Benzoate on the Growth, Survival and Aflatoxin Production Potential of Some Species of Aspergillus in Garri During Storage

Abstract: The antimicrobial effect of different concentrations (0.6, 0.4 and 0.2%) of sodium benzoate (SB) on the growth, survival and aflatoxin production potentials of Aspergillus niger, Aspergillus flavus and o Aspergillus fumigatus in packaged garri (2kg/pack) during storage at ambient temperature (30±2 C) was investigated. A decrease of 4.5, 2.5, 1.9; 4.5, 2.4, 1.8 and 4.6, 2.6 and 2.0 folds were recorded in the viable count of A. niger, A. flavus and A. fumigatus, for 0.6, 0.4 and 0.2 % SB treated samples respectively. The effectiveness of SB against the various species of Aspergillius was in the order 0.6 %> 0.4 %> 0.2%. However 1.2 and 1.7 folds increase in the viable count of A. niger, A. flavus and A. fumigatus were recorded in the non treated samples (controls). No aflatoxin was detected in all the samples treated with different concentration of SB. However, aflatoxin was detected in the samples inoculated with Aspergillus flavus although unspecified and irregular florescence was noticed in other samples (controls). Key words: Sodium benzoate, aflatoxin production, Aspergillus, Garri, cassava root

Shelf Stability and Enzyme Activity Studies of Ogi: A corn Meal Fermented Product

Abstract: Ogi slurry was produced by fermenting corn grains with previous steep water for 72h in the ratio of 100:0 Steep water: water and the resulting ogi slurry was called inoculated fermented ogi slurry. Shelf life studies of inoculated fermented ogi slurry were carried out for 60 days. The pH, titratable acidity, colour and flavour were monitored and were observed not to have changed throughout the 60 days period of investigation. Enzyme activity was determined in the inoculated fermented ogi slurry and results showed that proteinase activity was higher in inoculated fermented ogi slurry (6.05 + 0.01mg/ml) compared to the uninoculated ogi slurry (4.08 + 0.01mg/ml). A similar trend was observed for amylase and lipase activities

Glutamic acid production from cassava whey by Brevibacterium sp. G012

Cassava whey can be used as a substrate for glutamic acid production. Amylase from a Rhizopus sp. grown on rice bran hydrolysed cassava whey to fermentable sugars at 72.5% efficiency. A one-step fermentation of whey hydrolysate gave a low yield of glutamic acid with both Brevibacterium sp. G12 and Corynebacterium glutamicum: In a two-step process, the yield was 9.7-9.8 mg/ml with both bacteria after 36h. Whey sugars at 3% and urea as N. supplement enhanced the yield from G012 to 11.2 mg/ml after 36 h

Studies of food thickeners in Nigeria for contamination by aflatoxigenic forms of Aspergillus and their detection by PCR

This paper reports the contamination of ready-to-use food thickeners, collected from the South-East geo-political zone in Nigeria, by aflatoxigenic form of Aspergillus species. A total of 150 samples from different open markets were observed for fungal contamination by using serial dilution-spread plate method. Although, Aspergillus, Fusarium and Penicillium were the most frequently isolated fungi, Aspergillus species were found to be the most prevalent in all the samples. Furthermore, Aspergillus flavus and Aspergillus parasiticus produced aflatoxin on yeast extract sucrose (YES) media incubated for 10 to 15 days at 27 degrees C in a CO(2) incubator. Aspergillus niger showed no sign of any secondary metabolite on the media, set at similar conditions. Although, light microscopy was used to identify these fungi, based on colony morphology, PCR method was used to confirm genetic variation among the Aspergillus group, using ITS set of primers. Gel electrophoresis of PCR products confirmed the presence of Aspergillus species at an amplification range from 500 to 600 bp in all the samples tested. PCR was found to be a sensitive and a more reliable tool for detection and identification of Aspergillus species in food thickeners as opposed to conventional light microscopy. This is a first kind of mycological survey on the contamination of ready-to-use food thickeners sold in Nigeria

Volume 7 No. 2 2007 NUTRITIONAL STATUS OF MAIZE FERMENTED MEAL BY FORTIFICATION WITH BAMBARA-NUT

ABSTRACT Studies were conducted to develop an appropriate household/small scale enterprise level technique for the production of bambara-nut-fortified fermented maize dough or meal by comparing different treatments, processing methods and fortification levels. The effect of fortification of maize based traditional foods with legume protein, bambara-nut at 0%. 10% and 20% replacement levels, on the rate of fermentation and organoleptic product quality were investigated. Sensory characteristics, amino acid pattern, proximate composition (moisture, protein, fat, ash, carbohydrate) pH, titratable acidity and rheological properties (pasting temperature, peak viscosity, viscosity at 95 o C and 95 o C hold and viscosity at 50 o C) were used as the indices of quality. The results obtained showed that Bambara-nut addition caused only minimal changes in the proximate composition with the exception of protein content, which increased remarkably from 10.1% to 16.4% and 10.1% to 16.2% with 20% bambara-nut addition respectively for boiled and raw bambara-nut fortified fermented maize dough. The product pH decreased with concomitant increase in moisture, fat, ash and titratable acidity with increasing bambara-nut addition. A significant improvement was also achieved in the lysine and tryptophan pattern of the fortified dough compared to the unfortified lot. However, boiling bambara-nut for 20 min before incorporation into the maize for milling and fermentation imparted a desirable flavour. This results showed that the most appropriate technique for the production of bambara-fortified high protein fermented maize dough has been suggested to involve incorporation of boiled whole bambara-nut in soaked maize before milling and fermentation for improved sensory characteristics, enhanced nutritive value and optimal functional properties. Little or no changes in the pasting viscosity characteristics occurred in raw bambara-nut fortified fermented maize dough. Organoleptic evaluation revealed that the foods were well accepted. Based on the findings of the study, the application of Bambara-nut fortification to traditional foods suggests a viable option of promoting the nutritional quality of African maize -based traditional foods with acceptable rheological and cooking qualities