Food Science

The effect of pre-drying treatments on the proximate and phytochemical quality of oven-dried mushroom was evaluated using conventionally accepted methods. The pre-treatments used were dipping in 10% citric acid solution, dipping in 10% ascorbic acid solution and a control. The pre-treatments resulted in significant differences in pH, protein, vitamin C, some trace elements and phytochemicals present. Control sample had a protein content of 7.4%, while a range of 19.4% and 14.3% was recorded for samples pre-treated with citric acid and ascorbic acid respectively. The total phenolic content was in the range of 6.39 – 32.26 mg GAE/g of dry weight. Thus the use of these pre-treatments can be used to effect changes in some proximate and phytochemical components of oyster mushroom powder. Keywords: mushroom, oven-drying, blanching, citric acid, ascorbic acid

For green fodder yield and its contributing traits in Sorghum (Sorghum bicolor L.), genotypic and phenotypic coefficients of variability, heritability and genetic advance were estimated. Higher estimates of genetic variability were computed in internodal length followed by green fodder yield, plant height, number of leaves per plant and leaf area, whereas the least genetic coefficient of variability was observed in the days to 50% flowering. Higher amount of heritability was expressed by plant height followed by internodal length, number of leaves per plant, leaf area and green fodder yield. High estimates of genetic advance were computed for plant height followed by leaf area and internodal length. Correlation analysis at a genotypic level of the present breeding material indicated that plant height mainly increases with the increase in internodal length and with the increase in plant height, leaf area and number of leaves per plant, green fodder yield would increase. Path coefficients were computed to estimate the contribution of individual characters to green fodder yield in sorghum (Sorghum bicolor L.). Highest overall effect on green fodder yield was observed associated with plant height followed by internodal length, leaf area and number of leaves per plant.

The lipid composition of the heart, liver and brain of roan antelope was determined on a dry weight basis. The crude fat ranged between 4.16-8.65 g/100 g with corresponding contributing energy as 120-180 kJ/100 g and total fatty acid of 3.25-4.85 g/100 g. The fatty acids were (in % of total fatty acids): SFA: 46.3 (brain) > 39.5 (heart) > 37.7 (liver); MUFA (cis): 44.2 (brain) > 39.8 (heart) > 25.4 (liver); MUFA (trans): 0.131 (brain) > 0.121 (heart) > 0.053 (liver) and PUFA: 36.8 (liver) > 20.5 (heart) > 9.26 (brain). Best SFA level was C16:0 in brain (25.8 %) and in heart (25.2 %) but C18:0 in liver (17.3 %). C18:1 (cis-6) was highest MUFA in liver (12.7 %) but C18:1 (cis-9) was highest MUFA in heart (18.3 %) and brain (22.3 %). These n-6 PUFA were high in concentration: C18:2 (cis-9, 12) 2.05 -21.4 % and C20:4 (cis-5, 8, 11, 14) 3.91-13.3 %. SFA as food was 1.23-2.24 g/100 g and PUFA was 0.449- 1.20 g/100 g with corresponding energy contributions of 45.4-83.0 kJ/100 g and 16.6-44.2 kJ/100 g. AA/DGLA was 5.73-13.7; EPA/DHA was – to 0.027; LA/ALA was 7.48-60.6; n-6/n-3 was 2.72-51.9; PUFA/SFA was 0.200-0.976; MUFA/SFA was 0.676-1.01 and EPSI was 0.209-1.44. The only sterol of significance was cholesterol with a range of 88.7-1234 mg/100 g whereas total phospholipids range was 283-2791 mg/100 g with the brain being highest in concentration and the liver being lowest in both sterol and phospholipids respectively.

A twelve week nutritional study was conducted to investigate the effect of replacing soybean with copra meal on the growth performance of Clarias gariepinus. Two hundred and ten Juveniles of Clarias gariepinus with mean weight+/- 14.43g were stocked at a rate of (14) fourteen juveniles per treatment and replicated three times. The fish were subjected to five different dietary treatments with varying levels of copra meal replacing soybean at 0%, 10%, 20%, 30% and 40%. Feeding rate of 3% body weight per day was adopted. Fish growth was monitored regularly by weighing every two weeks. The mean weight gain(MWG), specific growth rate (SGR), percentage weight gain (PWG) were significantly different (p< 0.05) and highest values (14.28g, 98.96% 68.79%/day) were recorded respectively for fish fed diet 5 (40% copra meal) while fish fed diet 3 (20% copra meal) had the least values of MWG, PWG and SGR ( 60.52g,83.16% and 60.52%/day) respectively. Treatment 5 had the least feed conversion ratio (FCR) of 1.93, showing this treatment to be highly efficient while treatment 1, 2, 3 and 4 had the highest values ranging between 2.10 – 2.11 The protein efficiency ratio (PER) and gross feed conversion efficiency (GFCE)were significantly different (P<0.05). Highest values of PER and GFCE (1.73, 51.80%) were recorded for treatment 5 and least values of 0.84 and 47.30% were found in treatment 3 respectively. The positive relationship observed between the growth parameters and the level of copra meal in the diet showed that African cat fish can utilize Copra meal efficiently to improve growth. It was therefore concluded that up to 40% copra meal could adequately and efficiently replace soybean meal without any adverse effect on Clarias gariepinus diets.

The effect of rice bran in reducing the weight of the overweight / obese individuals was carried out with the following objectives: to conduct the feeding trial for overweight / obese adults for a period of three months and assess the impact of feeding on the body composition, anthropometry and biochemical profile of the adults. Forty overweight / obese women (each 20) in the age group of 30 to 60 years with no other complications formed the basis for inclusion in the study. Assessment of body composition for the selected women was carried out using Biospace Inbody 720. Each adult was fed with 75 grams (uncooked) of rice bran pasta in the form of recipes during the lunch. Biochemical parameters among the overweight and obese adults before and after the feeding trial was analysed. Statistical analysis revealed that there was no significant change after the feeding trial. The body protein increased from 7.04 to 7.09 kg among the overweight and from 7.41 to 7.48 kg among the obese adults. Soft lean mass had increased from 33.9 to 34.05 kg in overweight adults and from 35.74 to 36.04 kg in obese adults. Body fat mass among the overweight adults reduced to 29.09 kg after the feeding trial. A high degree of positive correlation (P<0.01) was observed between fat free mass and protein, total body water, soft muscle mass and mineral among overweight and obese adults. In conclusion, the results indicate that the feeding trials with rice bran incorporated pasta at 15 per cent level for overweight and obese adults did not significantly contribute to the reduction of overweight and obesity.

Pectin was extracted from fruits such as orange, apple, guava and grapes using different acids. Hydrochloric acid, sulphuric acid and nitric acid were used for extraction of pectin from dried fruit pieces. The level of pectin differed in the fruits depending on the acids added during the process of extraction. Generally fruits are dried to determine the yield of pectin. Various drying methods were adopted in this study to extract pectin from above mentioned fruits. The resulting pectin content of fruits was compared with drying methods adopted.

The levels of fatty acids, phospholipids and sterols were determined in the testes of bulls, bucks (goats) and African giant pouch rats found in Nigeria. Results showed testes weights variations were (gram wet weight): 48.6-48.5 (bulls); 23.4-23.5 (bucks); 5.72-6.04 (African giant pouch rats). Crude fat range was 2.65-3.00 g/100 g dry weight; SFA varied from 27.0-48.0 % of total fatty acids; total unsaturated fatty acids varied from 52.0-73.0 %; PUFA range was 13.2-15.3 %; PUFA/SFA range was 0.274-0.565; MUFA/SFA range was 0.810-2.13; AA/DGLA range was 18.8-74.5; LA/ALA range was 2.81-19.1 whereas n-6/n-3 range was 4.38-10.4 and EPSI (PUFA/MUFA) range was 0.265-0.370. In the phospholipids, lecithin (phosphatidylcholine) was highest in all the samples with values of 236-307 mg/100 g or 44.7-45.7 %. Among the sterols only cholesterol was of any significant level with values of 260-378 mg/100 g or 99.992-99.994 %. Chi-square (X2) analysis showed that SFA, AA/DGLA and LA/ALA were significantly different among the samples. In phospholipids, the following parameters were signicantly different among the samples: Cephalin, Lecithin, Ptd-L-Ser (PS) whereas all phospholipid parameters were significantly different among themselves in the bulls, bucks and the African giant pouch rats. Cholesterol was also significantly different among the samples.

Proximate composition, mineral composition and anti-nutrient factors were determined in the hull and cotyledons of the kernel of dika nut (Irvingia gabonensis) on dry weight basis. Higher values (g/100 g) protein, fat, ash, fiber, dry matter, fatty acid and calorific value were recorded in the cotyledon. In minerals, the levels in cotyledon were higher than hull in (mg/100 g): Na, K, Ca, Mg, Zn, Cu, Mn, Co, Fe, Cd, Ni, and P and in [K (Ca + Mg)], Ca/P and Ca/Mg. In the anti-nutrients, hull was higher in tannin, oxalate, phytate, phytin phosphorus, saponins, alkaloids and phytin phosphorus as a percentage of total phosphorus. The levels of Phy: Zn, Ca: Phy and Ca: Phy/Zn was good enough in the hull and cotyledon for the body to absorb calcium and zinc for its physiological activities. Significant differences existed between the hull and the cotyledon in all the parameters determined with high positive rxy at r = 0.05.

Effect of roasting temperature and time on the total polyphenols, flavonoids, total antioxidants and antioxidant properties of tigernut was studied using response surface methodology. Tigernut samples were roasted in an oven at the range of 150 – 200oC for 20 – 50 min. Out of the responses, only radical scavenging activity was not significantly affected by the roasting conditions. Roasting temperature affected the antioxidant contents significantly (p > 0.05) than roasting time. The optimum roasting temperature and time obtained was 200 oC for 20 min. The experimental values were very close to the predicted values and were not significantly (p > 0.05) different.

The levels of crude fat, fatty acids, phospholipids and phytosterols were determined in the unfermented and fermented samples of African locust bean seeds using gas chromatography techniques. Results showed crude fat varied from 16.9-19.5 g/100 g; SFA varied from 45.6 down to 42.1 % of total fatty acids, total unsaturated fatty acids varied from 54.4-57.9 %, PUFA range was 31.8 down to 31.0 % and PUFA/SFA ranged from 0.698-0.735. Both samples had high levels of n-6 fatty acids but low in n-3 fatty acids. In the phospholipids, lecithin was highest in the two samples with values ranging from 95.5-107 mg/100 g (46.1-51.4 %). The phytosterol values in the unfermented seeds ranged from 0.00-138 mg/100 g and in fermented seeds the range was 0.00-144 mg/100 g with sitosterol predominating in both samples. Whilst 100 g unfermented seeds would provide 13.5 g fatty acids, 100 g fermented seeds would provide 15.6 g fatty acids. The correlation coefficient was not significantly different in the fatty acids and phospholipids but significantly different in the phytosterols at r _{= 0.05}.