Effect of domestic processing on the cooking time, nutrients, antinutrients and in vitro protein digestibility of the African yambean (Sphenostylis stenocarpa).

The effects of processing (soaking, dehulling, fermentation and heat treatment) on the cooking time, protein, mineral, tannin, phytate and in vitro protein digestibility (IVPD) of the African yambean (AYB) were examined. The cooking time ranged from 90-155 minutes. Soaking reduced cooking time by about 50 percent. Soaking for 12 hours was the most appropriate to reduce cooking time, tannin and phytate levels. It improved in vitro protein digestibility (IVPD). Prolonged soaking (24 hours) decreased calcium (Ca) and iron (Fe) values by 19 percent and 35 percent, respectively. Dehulling showed that Ca, Fe, magnesium (Mg) and zinc (Zn) were concentrated in the seed coat of the AYB. The seeds soaked and dehulled retained Mg and Zn. Dehulling reduced tannin but had no significant effect on phytate and the IVPD of the AYB except for seeds soaked for 12 hours before dehulling. Soaking for 24 hours before dehulling significantly increased crude protein content by 16 percent (p < 0.05). Blanching and roasting increased the IVPD by 8-11 percent. Fermentation had no effect on the crude protein, Ca, Fe, Mg and Zn but significantly reduced phytate content of the AYB. Fermentation had no advantage over heat treatment with respect to improving the in vitro protein digestibility of the AYB.

Protein quality of some Nigerian traditional diets based on the African yambean (Sphenostylis stenocarpa) and pigeon pea (Cajanus cajan).

The protein quality of Nigerian traditional diets based on the African yambean (AYB) and pigeon pea (PP) were performed by in vivo and in vitro bioassays. The individual foods were processed, cooked, dried and mixed to resemble the traditional diets. Weanling male Wistar rats (45-55 g) were used for the bioassay. The rats were fed ad libitum for 35 days of which 28 days were for growth and 7 days for N-balance. All the eleven diets including casein (control) provided 1.6 g N/100 g diet. The parameters tested include PER, growth, N-balance, BV, NPU and apparent digestibility (AD). The rats fed the AYB diets, except AYB: Agidi (Ag), showed superiority in most of the parameters tested. There were significant positive correlations between PER and NPU (r = 0.925; p < 0.001); PER and AD (r = 0.908; p < 0.001); PER and body weight gain (r = 0.969; p < 0.001). The in vitro protein digestibility of the diets was significantly correlated (r = 0.80; p < 0.01) with the in vivo apparent digestibility. These parameters were used to rank the various diets. Crayfish protein was a better supplement to legume/cereal or legume starchy staple mixtures than leguminous oil seed. However, supplementation of PP: steamed corn (SC) diet with crayfish did not prove beneficial. The result showed that diets based on the African yambean, an under-exploited legume, are nutritious. The need for its reintroduction into the fare of the populace through increased production and appropriate processing technology is stressed. The results of this study can form a base for the standardization of Nigerian diets based on these legumes.

Nutritive value of baobab milk (gubdi) and mixtures of baobab (Adansonia digitata L.) and hungry rice, acha (Digitaria exilis) flours.

The baobab milk and fermented baobab/acha flour mixtures were analyzed chemically for their proximate, ascorbate, mineral and antinutrient composition. The dry pulp scraped from baobab fruits was kneaded, made into solution, extracted through cheese-cloth and stored frozen until analyzed. The acha and baobab grains were cleaned, fermented for 24 to 120 hours, dried and hammermilled into fine flours. The unfermented flours served as controls. The standard assay methods of AOAC were selected for use for the analysis of the nutrients and the antinutrients. The mixtures were composed of 70% acha and 30% baobab flours (70:30 protein basis). The baobab milk contained more protein (1.5%) and minerals (Fe, 17.8 mg; Ca 134.2 mg) than those of human milk (protein, 1.3%, Fe, 0.2 mg, Ca 30 mg) and cow milk (Fe, 0.1 mg; Ca 1.20 mg) and most leading national commercial infant formulas e.g. cerelac (Fe, 10.0 mg). The composite flours contained more nutrients than the baobab or the acha flour alone. The BF96 had greater advantage over other BF flours as a supplement to acha. The mixtures are within the reach of lower income group and can be incorporated into their diets.

Evaluation of the effect of processing techniques on the nutrient and antinutrient contents of pearl millet (Pennisetum glaucum) seeds.

This work was undertaken to evaluate the effect of soaking, sprouting, cooking and fermentation or their combinations on the nutrient and antinutrient contents of pearl millet seeds. Standard assay procedures were adopted to determine both the nutrient and the antinutrient concentrations of the products. The synergistic effect of cooking and fermentation improved the nutrient quality. The antinutrients were reduced to safe levels to a greater extent than did any of the other processing techniques or their combinations employed.

Production and chemical evaluation of some food condiments of Nigeria.

The study was aimed at investigating the nutrient and tannin composition of fermented legume seeds (oil bean, castor oil bean and African locust bean) used as food condiments in Nigeria. The legume seeds were purchased from local retailers, cleaned and subjected to varied fermentation periods. Standard assay techniques were adopted to analyze the parameters selected for use. The 4-day fermentation period caused the highest increases in protein and tannin and decreases in ash, lipids and non-protein nitrogen (NPN). The pulp of African locust bean had more protein an ash and the oil bean seeds less lipids and NPN. Fermentation times had varied effects on mineral levels. Fermentation for 4 d increased zinc, sodium and phosphorus except sodium for the African locust bean. The pulp had lower Zn and phosphorus than the seed. Fermentation for 4 d offers a greater advantage over other periods for production of nutritious and cheap food condiments in Nigeria.

The effects of sprouting times on nutritive value of two varieties of African yam bean (Sphenostylis stenocarpa).

Forty-eight rats (80-125 g) were used to determine the nutritive value of two sprouted varieties of African yam bean. The cream and brown varieties were each sprouted for 36, 48 and 72 h and blended with corn in a 70:30 ratio (protein basis) to provide 1.6 g N/100 g diet for the entire study period. Sprouting for 48 h caused an increase in most of the parameters tested for both varieties. Sprouting increased natural enhancement of nutrients.

Effect of germination and fermentation on the nutritional quality of bambara nut (Voandzeia subterranea L. Thouars) and its product (milk).

Five cultivars of bambara groundnut were selected on which to study the effects of germination and fermentation on their proximate composition. The cultivar that had the highest protein content was chosen to prepare unfermented and fermented milk. Standard assay techniques were adopted to determine the parameters selected for use. Germination caused a decrease in the protein, carbohydrate and starch; it increased sugar content, and had varied effects on the lipids contents of the dry samples. The anti-nutritional factor-tannin concentration was decreased. Germination and fermentation had varied effects on the nutrient compositions of the milk. Compared to the control, germination had the same effect as in the seeds. Fermentation further decreased some of the nitrogenous constituents, sugar and starch content of the milk and much more drastically the tannin content. Hydrolysis and other metabolic changes freed the nutrients from their bound forms while decreasing the quantity, but increasing the quality and availability of the nutrients.

Effect of soaking, sprouting, fermentation and cooking on nutrient composition and some anti-nutritional factors of sorghum (Guinesia) seeds.

This study was designed to determine the effect of soaking, sprouting, fermentation and cooking on nutrient composition and some antinutritional factors of sorghum seeds (guinesia). Standard assay procedures were adopted to resolve both the nutrients and the antinutritional factors content of the products. Combination of cooking and fermentation improved the nutrient quality and drastically reduced the antinutritional factors to safe levels much greater than any of the other processing methods tested.

Effect of sprouting on the nitrogenous constituents and mineral composition of pigeon pea (Cajanus cajan) seeds.

The study was aimed at evaluating the effect of sprouting on nitrogenous constituents and mineral composition of cream pigeon pea seeds. After 48 and 96 h of sprouting, there were increases in % moisture, crude protein, ash except during the 96 h; total nitrogen (TN), total non-protein nitrogen (TNPN); protein nitrogen (PN) and true protein nitrogen (TP). Sprouting caused increases in mineral levels except for phosphorus (P). Sprouting for 48 h offers greater advantage over 96 h.

The effects of varying sprouting periods on the nutritional quality of normal yellow corn (Zea mays).

Weanling male albino rats (45-60 g) were used to study the effects of varying sprouting periods on the nutritional quality of normal yellow corn. The yellow corn (YC) was sprouted for 24, 36 and 48 h (SYC24, SYC36, SYC48). The unsprouted corn (UYC) and casein (CA 100) served as negative and positive controls. African yam bean (AYB) was sprouted for 48 h and blended with the corn in a 70:30 (protein basis). Sprouting for 48 h caused decreases in most of the parameters tested except for the liver weight and N and calcium (CA) balance. The 24 h sprouting produced increases except for weight gain and PER, liver weight and N, phosphorus (P) and Ca intake and retention. The UYC produced increases higher than those of the test groups except for digested N, NPU, liver moisture, Fe intake and absorption. Casein significantly increased all parameters than for the test groups except for digested and retained N, P and Fe intakes. The advantages of sprouting for 24 or 36 h out-weighed those of 48 h.

Mineral utilization of malted sorghum and corn with added crayfish in rats.

Forty adult rats were used to study the mineral balances of malted and unmalted wet- or dry-milled sorghum and corn combined with crayfish and fed rats for 12 days. Five out of the twelve days were for adjustment and the rest for balance period. These mixtures each was calculated to provide 1.6 g N daily for the entire study period. Malting and wet milling produced increases in crude protein content of the cereal grains. However, the increases were much more evident in sorghum. Wet milling caused increases in calcium retention in corn groups. It produced the same effect on phosphorus balance only in sorghum groups. On the other hand, it produced positive iron balances only in unmalted corn and malted sorghum groups. The results suggest improved mineral nutriture due to malting except for the Fe retention of the MDC:CR group.

Growth, liver composition, and calcium balance of rats fed sorghum supplemented with two levels of beans.

A 35-day experimental study consisting of 28-day growth and 7-day calcium (CA) balance periods was conducted to assess the effects of fibre and N ratios on growth and Ca balance of rats. Growth and Ca balance of rats (45 80 g) fed mixtures of cooked (CS) and uncooked (RS) sorghum and dehulled (DB) and undehulled (UB) bean were studied. The diets contained 10% protein. Casein served as the control protein. The control group ate more food except for the group fed the CS:DU (60:40) diets (P less than 0.05) had higher values for all parameters tested than the test groups. There were increases in food and Ca intakes, fecal Ca, weight gain, protein efficiency ration (PER), liver weight and composition except for the low moisture value for the CS:DS (60:40) group when N ratios were changed from 80:20 to 60:40. These results appear to indicate that fiber and N ratio had significant effects on growth liver composition and calcium balance of the rats.

Nutritional responses of rats fed mixtures of plant and animal proteins.

Twenty four male rats (45-65 g) were used to determine the nutritional responses to mixed plant and animal protein diets. Rats were fed various mixtures of sorghum (S), pigeon pea (PP), bread fruit (TAP) plus crayfish (CR) to provide 1.6 g N/100 g of daily diet for a 35-day study period. Three different diets were fed to 6 rats assigned to each diet on the basis of body weight. Combination of PP:CR caused increases in N intake and retention, weight gain, and PER higher than for those of the other test groups. Its values for N intake and retention, and BV were higher than for those of the control except for food intake, NPU, weight gain and PER. Substitution of CR (20%) with TAP and PP as supplements to S decreased food intake, weight gain and PER and increased N intake, digested and retained N, NPU and BV. The results appear to indicate that (a) PP:CR blend was better than other blends as judged by the parameters, and (b) TAP and PP were superior to CR alone as supplement to S.