Objective: Most of the peanut butter marketed in Nairobi is processed in cottage industry and its aflatoxin contamination status has not been documented. This study was therefore conducted to determine the status of aflatoxin contamination in groundnuts and peanut butter in Nairobi and Nyanza. Methodology and results: Eighty two fresh samples comprising raw and roasted groundnuts and peanut butter were obtained from market outlets and cottage processors in Nairobi and Nyanza regions. The marketers and processors were asked for information on the source of groundnuts. The incidence of Aspergillus section Flavi was determined using standard laboratory methods. Defective nuts in raw groundnuts were determined by manual sorting. Aflatoxin analysis was done using competitive ELISA technique. Groundnuts in Nairobi were imported from Malawi while those Nyanza were grown in the region. The fungal species isolated from the samples were: Aspergillus flavus (L and S strains), A. parasiticus, A. niger, A. tamari, A. alliaceus, A. caeletus and Penicillium spp. The percentage of defective nuts among all unsorted groundnuts ranged from 0.0% to 26.3%. The mean percent defective nuts was higher for Nairobi samples than Nyanza. Aflatoxin levels in all samples ranged from 0 to 2377.1 µg/kg. The mean aflatoxin level was higher for raw samples from Nairobi than Nyanza. The source of groundnuts and defective nuts were positively associated with aflatoxin levels. Conclusions and application of findings: The source of groundnuts and presence of defective nuts were identified as the main factors influencing increased aflatoxin contamination in the cottage industry. Mechanisms for inspection and certification of imported groundnuts should be put in place accompanied by effective monitoring for compliance to set aflatoxins standards. All the market players should sort their groundnuts before selling or processing in order to reduce aflatoxin contamination of peanut butter.

Proximate analysis for moisture, crude protein, crude fat and total ash was carried out on dagaa (Rastrineobola argentea), a small pelagic fish specie found in Lake Victoria. The first phase of the study involved sampling of fresh, sundried (for 1 day, 2 days, 3 days, 4 days) and retail market dagaa. The second phase of the study involved pre-washing of fresh dagaa with selected solutions namely, salted solution (3% NaCl), chlorinated solution (100 ppm) or potable tap water (control) and thereafter oven-drying the respective pre-washed samples at 30 o C (31hrs), 40 o C (23hrs) or 50 o C (15hrs). Results showed that the crude protein composition of fresh dagaa (74.4% dry weight basis, dwb) was significantly higher (p<0.05) than values in market samples (62.5% dwb). After oven-drying at 30 o C, the salted-wash treatments resulted to significantly lower (p<0.05) crude protein content of 60.4% (dwb) when compared with the chlorinated (64.6% dwb) and control-wash treatments (64.1% dwb).The crude fat content in fresh dagaa (14.8% dwb) was significantly higher (p<0.05) than levels in market samples (13.9% dwb).The salted-wash treatments showed significantly lower (p<0.05) crude fat content (15.9% dwb) than the chlorinated (17.0% dwb) and control (16.9% dwb) wash treatments after ovendrying at 30 o C.The total ash content in fresh dagaa (10.3% dwb) was significantly lower (p<0.05) than levels in market samples (13.5% dwb).The salted and chlorinated-wash treatments exhibited significantly higher (p<0.05) total ash content (19.9%, 16.7% dwb, respectively) than the control-wash treatment (15.9% dwb) after drying at 40 o C. In this study, oven-drying of dagaa at 40 o C after washing with chlorinated (100ppm) solution was suggested with regard to the optimal retention of the crude protein and fat levels of the dried dagaa.These conditions are achievable at the local community level through use of solar driers whereas sodium hypochlorite products are accessible to most of the households involved in dried fish processing.

Dagaa (Rastrineobola argentea) is one of the most important fish foods for the lowincome households in the Nyanza Province, Kenya. However, the off-flavour and offodour that results from the traditional sun-drying process of sun-dried dagaa is a major disincentive to the use of the fish for human consumption, hence leading to utilization in animal feed. Chemical analyses for pH, Thiobarbituric reactive substances (TBARS), Total volatile bases-nitrogen (TVBN) and aerobic bacterial counts were carried out on dagaa sampled from various process steps within the open field sun-drying and market conditions. Dagaa was also oven-dried at 30 o C, 40 o C and 50 o C after washing with selected solutions namely salted (3% sodium chloride), chlorinated solutions (100ppm) and potable tap water (control). Results indicated that TBARS values increased significantly (p<0.05) from 1.39 mgMA/kg in fresh fish to 10.55 mgMA/kg in the market samples. The TVBN values increased significantly (p<0.05) from 9.42 mgMA/kg in fresh fish to 29.51 mg/ 100g in the market samples. The pH values declined significantly (p<0.05) from pH 6.72 in the fresh fish to pH 5.88 in the market samples .Lipid oxidation (TBARS) was significantly (p<0.05) higher in dagaa subjected to salted-wash treatments when compared to the chlorinated and control-wash treatments. The rate of lipid oxidation was significantly (p<0.05) higher at elevated temperatures of 50 o C relative to 30 o C and 40 o C conditions. The TVBN levels observed in the salted and chlorinated-wash treatments showed significantly (p<0.05) lower TVBN values when compared with the control-wash treatments. However, the values of TVBN obtained at 30 o C were significantly (p<0.05) higher when compared with the 40 o C and 50 o C drying temperature conditions. The salted-wash treatments resulted in lower pH values relative to the chlorinated and control-wash treatments on drying at 30 o C and 40 o C. In this study, the most appropriate treatment that showed the least TVBN and moderate TBARS values was drying the dagaa at 50 o C after washing with chlorinated solution.

Objective: To determine the most effective method of extracting metabolites from the two herbs Ziziphus abyssinica and Tamaridus. Indicus. Methodology and results: The methods used included cold and soxhlet extraction using methanol as the solvent and hot extraction using distilled water. To determine the efficiency in which compounds are extracted TLC was performed on silica gel aluminium plates using ethyl acetate: formic acid: glacial acetic acid: water (100:11:11:27). To determine the quantity of phenolic compounds in the extract, the Folin and Ciocalteau's method (1927) was used, using Gallic acid in various concentrations. For the total quantity of flavonoid compounds, the method of Miliauskas et al. (2004) was used. To determine the Proanthocyanidin content in the extract a method previously reported by Ayoola et al, 2006 was used. To measure the antioxidant capacity of the extracts the hydrogen donating or free radical scavenging activity, was measured using the stable radical DPPH. The compounds extracted by all the methods were about seven but the difference was noted when the individual compounds were analysed. The cold extraction on the herb extract of Z. abyssinica had significantly high amount of total phenols 1.99g/100g of sample than both soxhlet and water extraction with 1.51g and 0.61g/100g of sample respectively. The results of T. indicus indicate that the extracts from the soxhlet and cold extraction methods contained a significantly low amount of all the three compounds compared to the water extracts Conclusion and application of results: The method best suited for obtaining extracts from the two herbs T. indicus and Z. abyssinica is, cold method of extraction with methanol as the solvent for Z. abyssinica and hot extraction using distilled water for T. indicus. The results obtained give guidance to the fact that using both herbs would result in a better preservative than using one herb since the identified compounds would complement each other.

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