Antinutritional factor content and hydrochloric acid extractability of minerals in pearl millet cultivars as affected by germination.

Four pearl millet cultivars of two different species--Kordofani and Ugandi (Pennisetum typhoideum) and Madelkawaya and Shambat (Pennisetum glaucum)--were germinated for 6 days. The germinated grains were dried and milled. Phytic acid and polyphenol contents and hydrochloric acid (HCl) extractability of minerals from the malt flours were determined at intervals of 2 days during germination. Phytic acid and polyphenol contents decreased significantly (P <0.01) with an increase in germination time, with a concomitant increase in HCl extractable minerals. However, the major mineral content was significantly decreased while that of trace minerals was increased with germination time. When the grains were germinated for 6 days, Madelkawaya had higher extractable calcium while Ugandi had higher extractable phosphorus, whereas iron and manganese recorded high levels in Shambat and Madelkawaya, respectively. There was good correlation between antinutritional factors reduction and the increment in extractable minerals with germination time.

Development of weaning food from sorghum supplemented with legumes and oil seeds.

BACKGROUND: The development of low-cost, high-protein food supplements for weaning infants from local and readily available raw materials is a constant challenge for developing countries. OBJECTIVE: To formulate, develop, and assess the nutritive value, acceptability, and keeping quality of sorghum-based staple dried flakes as instant weaning foods. METHODS: Weaning blends composed of 42% sorghum supplemented with 20% legumes, 10% oil seeds, and 28% additives (sugar, oil, skim milk powder, and vanillin) were prepared according to FAO/WHO/UNU recommendations and processed in a twin-roller drum dryer. The effects of fermentation and of the addition of malt on the nutritive value and functional properties of the blends were investigated. RESULTS: The blends were found to contain 16.6% to 19.3% protein, 68.7% to 72.7% carbohydrate, 0.9% to 1.3% fiber, and 405.8 to 413.2 kcal of energy per 100 g. The iron content of the blends ranged from 5.3 to 9.1 mg/100 g, and the calcium content ranged from 150 to 220 mg/100 g. All blends reconstituted well and formed a soft paste when stirred with hot or cold water. The water-holding capacity, wettability, and bulk density were within the ranges of corresponding values of commercial weaning foods. Sensory attributes, viscosity values, and in vitro digestibility varied among the blends, whereas lysing content improved considerably (p < or = .05) for all blends. All blends had similar keeping quality, with no signs of spoilage or development of off-flavors or colors after 10 months of storage. Most blends remained free of aflatoxins. CONCLUSIONS: Legumes and oil seeds can be effectively used in sorghum-based weaning foods as an acceptable protein and mineral supplement.

Study on furundu, a traditional Sudanese fermented roselle (Hibiscus sabdariffa L.) seed: effect on in vitro protein digestibility, chemical composition, and functional properties of the total proteins.

Furundu, a meat substitute, is traditionally prepared by cooking the karkade (Hibiscus sabdariffa L.) seed and then fermenting it for 9 days. Physicochemical and functional properties of raw and cooked seed and of furundu ferments were analyzed. Furundu preparation resulted in significant changes in karkade seed major nutrients. Total polyphenols and phytic acid were also reduced. The increase in total acidity and fat acidity coupled with a decrease in pH indicates microbial hydrolysis of the major nutrients; proteins, carbohydrates, and fats. In vitro digestibility of the seed proteins reached the maximum value (82.7%) at the sixth day of fermentation, but thereafter it significantly decreased. The effect of furundu preparation on N solubility profiles and functional properties, such as emulsification and foaming properties and other related parameters, is investigated in water and in 1 M NaCl extracts from defatted flour samples. The results show that cooking followed by fermentation affects proteins solubility in water and 1 M NaCl. The foaming capacity (FC) from the flour of raw seed decreased as a result of cooking. Fermentation for 9 days significantly increased the FC of the cooked seed, restoring the inherent value. Foam from fermented samples collapsed more rapidly during a period of 120 min as compared to the foam from raw and cooked karkade seeds; stability in 1 M NaCl was lower as compared to those in water. In water, the emulsion stability (ES) from the fermented samples was significantly higher than that of the raw seed flour. Addition of 1 M NaCl significantly decreased the ES of the fermented samples.

In vitro availability of minerals of some tropical and citrus fruits as influenced by antinutritional factors.

Four tropical fruits and three citrus fruits were analyzed for moisture, ash, antinutritional factors (phytate, oxalate, and polyphenols) contents, and total and available minerals. Moisture contents ranged from 6.0 to 83.17% for tropical fruits while that of citrus fruits ranged from 88.20 to 89.50%. Ash contents ranged from 2.56 to 4.50% and from 3.83 to 4.83%, for tropical and citrus fruits, respectively. All fruits contained no oxalate while phytate and polyphenols ranged from 48.1 to 134.1 mg/ 100 g and from 0.115 to 0.34%, respectively. For all fruits major minerals contents ranged from 7.7 to 433.3 while trace ones ranged from 0.116 to 1.91 mg/100 g. In vitro availabilities of major minerals (% of total) varied from 11.1 to 86.2% while for minor ones it ranged from 13 to 72.5%.

Effect of cooking on protein solubility profiles of faba beans (Vicia faba L.) grown using different nutritional regimes.

A field experiment was carried out to study the effect of cooking on protein solubility profiles of mycorrhizal inoculated, phosphorus and sulphur fertilized faba beans under two water regimes. The results indicated that cooking significantly (p < or = 0.05) increased the G3-glutelin fraction as well as the insoluble protein but significantly (p < or = 0.05) decreased the globulin and albumin fractions; prolamin, G1-glutelin and G2-glutelin fractions were slightly increased. Mycorrhizal inoculation and mycorrhiza + phosphorus + sulphur fertilization significantly (p < or = 0.05) increased albumin content. All fertilizer treatments significantly (p < or = 0.05) decreased the insoluble protein.

Fractionation, solubility and functional properties of wheat bran proteins as influenced by pH and/or salt concentration.

The content, fractionation, solubility and functional properties of wheat bran proteins as well as the effects of pH and/or NaCl concentration on some of these functional properties were investigated. The protein content of the bran was found to be 16.80%. Albumin and glutelin are the major fractions of wheat bran proteins. The minimal protein solubility was observed at pH 5.5, the maximum at pH 11.5. The emulsifying capacity, activity and emulsion stability as well as foaming capacity and foam stability were greatly affected by pH and salt concentrations. Lower values were observed at acidic pH and high salt concentration. The least gelation concentration of wheat bran proteins was found to be 16% when the proteins were dissolved in 1.0 M NaCl. The total protein was highly viscous and dispersable with water-holding capacity of 4.20 mL H2O/g protein, oil-holding capacity of 1.70 mL oil/g protein and bulk density of 0.29 g/mL while dispensability was found to be 77.30%.