RETRACTED ARTICLE: Some quality attributes of heat-moisture treated water yam (Dioscorea alata) starch

This study investigated the effect of autoclave and oven heat-moisture treatment on some quality attributes of water yam starch. The water yam starch was adjusted to moisture content of 15–35% and subjected to heat-moisture treatment (HMT) using autoclave (at 120°C for 1 h) and oven (at 120°C for 12 h). Physicochemical, functional and thermal properties of the modified starches formed were carried out. Increase in amylose and resistant starch content of the samples occurred after the treatment. The water and oil absorption capacities also increased after HMT from 74.40 to 135.46% and 0.65 to 1.37 ml/g respectively. Swelling power was reduced while the solubility increased compared to native starch. Pasting time and temperature increased after HMT. A reduction in peak viscosity (643.03–80.82 RVU), trough (441.33–65.79 RVU), breakdown (203.13–93.58 RVU), and final viscosity (549.29–112.75 RVU) and set back (108.17–40.17 RVU) was noticed. Moisture content above 15% resulted in biphasic endotherms in both treatments, T0, Tp, Tc and Tc−T0 also increase. The temperature of the heating medium was found to affect the RS content of the starches

Some quality attributes of heat-moisture treated water yam (Dioscorea alata) starch

This study investigated the effect of autoclave and oven heat-moisture treatment on some quality attributes of water yam starch. The water yam starch was adjusted to moisture content of 15-35% and subjected to heat-moisture treatment (HMT) using autoclave (at 120oC for 1h at 15psi) and oven (at 120oC for 12h). Physicochemical, functional and thermal properties of the modified starches formed were carried out. Increase in amylose and resistant starch content of the samples occurred after the treatment. The water and oil absorption capacity also increased after HMT from 74.40 to 135.46 % and 0.65 to 1.37ml/g respectively. Swelling power was reduced while the solubility increased compared to native starch. Pasting time and temperature increased after HMT. A reduction in peak viscosity (643.03- 80.82 RVU), trough (441.33-65.79 RVU), breakdown (203.13-93.58 RVU), and final viscosity (549.29-112.75 RVU) and set back (108.17-40.17 RVU) was noticed. Moisture content above 15% resulted in biphasic endotherms in both treatments, To, Tp. Tc and Tc-To also increased. The temperature of the heating medium affected the RS content of the starches at higher moisture content.Keywords: Autoclave, heat-moisture treatment, oven, resistant starch, water ya

Effect of natural fermentation on nutritional composition and anti-nutrients in soy-wara (A Nigerian fried soy-cheese)

This study was carried to evaluate the effect of natural fermentation on nutritional composition and anti-nutrients in soy-wara. A total of 100 samples consisting of five treatments of 20 samples per each treatment were studied. Yellow soybeans were soaked and fermented for 24 hrs, 48 hrs, 72 hrs and 96 hrs respectively at 27±2°C with 0 hr as control. Fermented soybeans were used for soy-wara production and soy-wara samples were evaluated for nutritional (amino acid, vitamin and mineral profile) and anti-nutritional (phytate, tannin and trypsin inhibitor activity) qualities. Results of amino acids analysis showed that tryptophan, isoleucine, methionine, phenylalanine, leucine and lysine contents in the fermented soy-wara ranged from 3.49 to 6.75, 21.94 to 24.41, 20.60 to 23.98, 22.11 to 27.15, 33.16 to 36.51 and 24.16 to 26.27 mg/100 g respectively. The values of thiamine, riboflavin and niacin contents in the fermented soy-wara ranged from 1.60 to 1.87, 1.44 to 1.71 and 2.21 to 2.78 mg/100 g respectively. The mineral elements calcium, iron, potassium, sodium, phosphorus and magnesium contents in the fermented soy-wara ranged from 17.65 to 19.08, 6.94 to 8.41, 29.76 to 30.69, 8.31 to 9.42, 27.52 to 28.55 and 21.02 to 24.83 mg/100 g respectively. Soaking and fermentation reduced the tannin content from 115.64 to 43.26 mg/100 g; phytate content from 153.81 to 47.16 mg/100 g, trypsin inhibitor from 96.56 to 1.10 mg/100 g and protease inhibitor from 98.11 to 1.2 mg/100 g respectively. In conclusion, natural fermentation of the legume reduced anti-nutritional factors and improved the nutrient composition of the product.</p

Quality characteristics and consumer acceptance of bread from wheat and rice composite flour

The quality characteristics and consumer acceptance of wheat-rice composite flour bread were evaluated. Substitution of rice flour was done in wheat flour from 0 to 100% and the composite flour was used to produce bread. The bread samples were subjected to proximate, physical, and sensory analyses. The results showed significant differences (p ≤ 0.05) between the proximate compositions of bread samples studied. Bread from control (100% wheat flour) had moisture content of 28.61±0.28%. Bread from 10-50% wheat-rice composite flour had moisture contents ranged from 28.04±0.41 - 24.81±0.40%. The oven spring of the samples from control (100% wheat flour) had the highest value of 1.12±0.28 cm. The oven spring of wheat-rice composite bread ranged between 1.00±0.22 and 0.82±0.38 cm. There was inverse relationship between loaf weight (g), loaf volume and specific volume and the quantities of rice flour added to the wheat flour. The results of consumer acceptance showed that bread with 70:30 wheat: Rice flour ratio was acceptable to the consumers. In conclusion, bread of good quality and good consumer acceptance could be made from wheat-rice composite flour.</p

Evaluation of nutritional composition, physico-chemical and sensory properties of ‘Robo’ (A Nigerian traditional snack) produced from watermelon (Citrullus lanatus (Thunb.) seeds

This study evaluated the nutritional composition, physico-chemical and sensory properties of ‘Robo’ (a Nigerian traditional snack) produced from watermelon seeds in order to improve the utilization of watermelon seeds in producing value-added products, acceptable to the consumers. Watermelon seeds were dehulled, dried and used to prepared ‘Robo’ in the laboratory and control samples were prepared from melon seeds. The proximate analysis, amino acid profile, vitamin, mineral and heavy metal profile and consumer acceptance of the ‘Robo’ samples were determined using standard methods. The results showed that there were no significant differences (p≥0.05) in the proximate composition of the ‘Robo’ samples from watermelon and melon seeds. There were significant differences (p≤0.05) in amino acid, vitamin and mineral profile of ‘Robo’ samples from watermelon and melon seeds. The amino acid concentration in g/100 g crude protein of ‘Robo’ for lysine, arginine and leucine were 4.58±0.01, 1.82±0.00 and 4.92±0.01 respectively for ‘Robo’ produced from watermelon seeds while 4.91±0.01, 2.01±0.00 and 5.16±0.01 respectively were recorded for ‘Robo’ produced from melon seeds. The study showed that the ‘Robo’ samples contained high amounts of vitamin B-complex and minerals and low amounts of heavy metals. In conclusion, the ‘Robo’ samples from watermelon seeds and control samples had high sensory scores and were well acceptable to the consumers. With these research findings, watermelon seeds could be used for the production of ‘Robo’ as a promising raw material. This will create ready-made market for the underutilized watermelon seeds and as well as creating more income to watermelon farmers.</p