This research work aimed at assessing the metal composition of the cotyledons of Citrullus colocynthis (egusi) and Irvingia wombolu (ogbono) as well as cassava chips sold in open markets in the five states of the South-Eastern Nigeria. These food materials were sampled from 135 stores and markets in three waves (Wet season, Harmattan and Dry season) between February, 2015 and March, 2016 in each of the five states in south eastern Nigeria (Enugu, Anambra, Imo, Abia and Ebonyi). The food materials were analyzed for Zinc, Lead, Copper and Iron using the Atomic Absorption Spectroscopy (AAS) method. The concentrations of these metals were not higher than the maximum permissible limit set by NAFDAC in Nigeria except for Lead in Enugu State ((0.042±0.068 mg/g). The highest quantity of Lead was detected in Citrullus colocynthis (0.039±0.006 mg/g) while the least concentration was detected in Cassava chips (0.009±0.005 mg/g). Lead was detected in samples collected across all the seasons (Wet season, Dry season and Harmattan). The high concentration of Lead in the sampled food materials from Enugu state across all the waves of sample collection that violated the permissible limits of lead set by WHO and NAFDAC is of public health concern. Lead exposure has been shown to cause severe health challenges thus regular monitoring of these toxic heavy metals from foods sold in markets is essential, to prevent their excessive build-up in the food chain. The inference of this study reveals that these food materials sold in the open market are not completely safe for consumption as a result of lead contamination due to poor handling and processing. Findings from this study will be of great help to all stakeholders in this area of interest such as researchers and environmental regulators, relevant government agencies saddled with the responsibility of ensuring the safety of foods consumed in Nigeria.

Treatment of Cassava whey with AspergiIlzcs niger was investigated. Heated cassava whey supplemented with ammonium sulphate (NH,),SO, and potassium di-hydrogen phosphate (KH,PO,) called supplemented cassava whey (SUCW) ; heated but unsupplemented cassava whey (USCW) ; and cassava whey as is, unsupplemented and unheated (UHCW), were used as waste sources and growth media. Total reducing sugars, starch, total carbohydrate, specific gravity, hydrocyanic acid (HCN), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of A. niger inoculated samples and uninoculated set were monitored on a time course basis for 5 days using standard methods. Percentage reductions in the BOD and COD were 69.7 and 54.5 respectively for SUCW samples; 42.4 and 29.5 for USCW samples while values for UHCW were 9.0 and 4.5. The reductions in reducing sugars, starch, total carbohydrate, specific gravity and cyanide content in descending order were SUCW; USCW and UHCW. The heated and A. niger inoculated cassava whey samples were better purified than both the unheated but inoculated and unheated m d uninoculated cassava whey samples.

No abstract

Post-harvest deterioration and rot caused by diverse microorganisms is the single most important factor militating against yam production in Nigeria. In an approach towards the development of ecofriendly antifungal compound in controlling yam rot, ethanol and aqueous extracts of six commonly available plants: Vernonia amygdalina, Ocimum gratissimum, Azadirachta indica, Cymbopogon citratus, Carica papaya and Citrus sinensis were tested in combination for their synergistic effect against Botryodiplodia theobromae. Four different extract concentrations (2.5%, 5.0%, 7.5% and 10%) were obtained from each extract mixture. Cold solvent extraction method was used for the extraction of plant materials while food poisoning technique was used for in vitro screening of plant extracts against rot inducing fungal organism. Botryodiplodia theobromae was tested to be pathogenic on healthy yam tubers with rot incidence of 80 mm. The synergistic effects of the combined extract varied with the plants combined, solvent of extraction, concentration of extract and test fungi. Ethanol extract showed greater effect in the inhibition of the entire organism than aqueous. All the extract combinations that had Neem as a component did better than other combinations in aqueous extracts. Inhibition of fungal growth was best observed at 7.5% and 10% extract concentrations. The highest inhibitory effect on the test organism (Botryodiplodia theobromae) was by the combination of Neem/Bitter leaf and Orange/Scent leaf, with values of 98.40±0.095% and 94.24±0.583% respectively for aqueous while the highest inhibition for ethanol extract was observed from Scent leaf/Bitter leaf and Pawpaw/Lemon, with values of 99.80±0.000% and 98.83±0.619% respectively these were significantly (P<0.05) better than other combinations. With respect to the synergistic activity between the plants materials combined in this study, all the combinations showed great synergism against the test organisms. This is likely to be a means of achieving pragmatic, effective control and prevention of food spoilage, since the development of new classes of antifungal agents is of paramount importance. The crude aqueous and ethanolic extracts of all the six plant extracts showed potential synergy on organisms responsible for yam rot, hence they are recommended for the control of rot inducing microbial organisms.