Yams (Dioscorea species) and cocoyam (ariods) are major staples that are widely consumed in tropical and subtropical countries, especially Nigeria.Up till now, there is limited information on the phenolic compounds and antioxidant activity of yams and cocoyam species in this tropical region.Three under-utilized Nigerian yams (Dioscoreacayenensis, Dioscoreadumetorum, Dioscoreabulbifera) and cocoyam (Xanthosomamaffa (Scoth)) were analyzed for total polyphenols, total flavonoids and antioxidant activities applying three commonly used assays: DPPH, ABTS, and ORAC. Correlation analysis wasperformed to determine the contribution of polyphenols and flavonoids toantioxidant activities. The total polyphenol content of the samples ranged from 7.02 to 163.37mg Gallic Acid Equivalent(GAE/100gFW), while the total flavonoid content of the samples ranged from 3.14 to 155.38mg Catechin Equivalent(CE/100gFW). The antioxidant activities evaluated by DPPHassay ranged from 88.17 to 729.39 Trolox Equivalent (TE/100gFW), whileABTSvalues ranged from 32.49 to 756.0 Trolox Equivalent (TE/100gFW)and ORAC assay ranged from 459.29 to 669.45mg Trolox Equivalent (TE/100gFW) respectively. Significant correlation was observed between total polyphenols and DPPH radical scavenging activity (R 2 =0.897);total polyphenols and ABTS(R 2 =0.931),andbetween total polyphenols and ORAC (R 2 =0.707). The correlation between total flavonoid and DPPH(R 2 =0.992), and between total flavonoidand ABTS(R 2 =0.744) respectively. The polyphenol, flavonoid and antioxidant activity of Xanthosomamaffa (Scoth) were higher and significantly different (P<0.05) from the yamsDioscoreaspecies. Extracts from these under-utilized yams and cocoyam tubers can play a considerable role in boosting immunity against human diseases caused by free radical reactions like cancer, cardiovascular disease, diabetes and aging.

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Soy flour from soybean was processed to produce fresh tofu using three coagulants namely lime, Epson salt and tamarind. The results obtained showed that the pH of the samples were 7.20 for Epson salt, 5.00 for lime and 5.50 for tamarind. There were significant differences (p< 0.05) in the weight increase of all the samples with Epson salt (46.62 kg) as the highest. Epson salt had the least coagulation time of 6 min. The result of the proximate analysis shows that there were significant differences (p< 0.05) in protein, carbohydrate and moisture content in the three samples with the value of protein in Epson salt (12.40) as the highest. Further analysis revealed that there were significant differences (p<0.05) in emulsifying capacity, oil absorption capacity and swelling index in all the samples. The value of the water absorption capacity of Epson salt (4.70 g/ml) was significantly different (p< 0.05) from lime (3.80 g/ml) and tamarind (3.70 g/ml). In the mineral composition there were significant differences (p< 0.05) in Ca, Mg, K, P, Na and Fe in all the samples though K had the lowest value. There were significant differences (p<0.05) in the total fungal and viable counts. The total fungal count was least in Epson salt (2.00 x 10 3 CFU/g) while the total viable count was also least in Epson salt (2.6 x 10 3 CFU/g) after 6 days of ambient storage; however, it was highest in tamarind coagulated tofu. Epson salt coagulated fresh tofu was highly appreciated for ranking highest in protein, Ca, Mg and lowest in total fungal and viable count.

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Catfish (Clarias buthupogon) was treated with 10% w/w NaCl and 15% w/w NaCl with or without the addition of spices (1% w/w garlic powder and 1% w/w red pepper) and allowed to ferment naturally and at room temperature (28 ± 2°C) for two weeks. Bacte rial, chemical and sensory analyses were carried out on the unfermented non-salted and fermented salted samples of the fish species. Results obtained revealed that fermentation and salting caused a remarkable reduction in the total bacterial count from 2.29×10 6 to 3.80×10 5 cfu/g. There was also reduction in pH from 7.29 to 5.26. The predominant bacteria isolated from the samples were Lactobacillus sp, Staphylococcus spp for the unfermented non salted and fermented salted samples respectively while total titratable acidity increased from 0.63 to 1.44%. Chemical analysis result showed that fat and ash contents increased with fermentation and salting while moisture, protein and Nitrogen free Extracts (NFE) contents decreased with fermentation and salting of C. buthupogon. Free fatty acid, peroxide value and total volatile base (TVB) also showed increase with fermentation. Peroxide value ranged from 5.22 mEq/kg for unfermented non-salted to 8.43 mEq/kg for fermented 15%w/w salted products while total volatile base increased from 5.63 mgN/100 g unfermented non-salted to 16.85 mgN/100 g for fermented 10%w/w salted products. Sensory analysis indicates that stew containing fermented samples treated with 10%w/w NaCl and spices were more preferred than others.