Amro B. Hassan

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.

Effect of γ radiation processing on fungal growth and quality characteristcs of millet grains

Abstract The aim of this study was to evaluate the effect of gamma radiation processing of millet grains on fungal incidence, germination, free fatty acids content, protein solubility, digestible protein, and antinutritional factors (tannin and phytic acid). The grains were exposed to gamma radiation at doses 0.25, 0.5, 0.75, 1.0, and 2.0 kGy. Obtained results revealed that radiation of millet grains at a dose level higher than 0.5 kGy caused significant (P < 0.05) reduction on the percentage of fungal incidence and the free fatty acid of the seeds, while, no significant change in the germination capacity was observed of the grains after radiation. Additionally, the radiation process caused significant (P < 0.05) reduction on both tannins and phytic acid content and gradual increment on in vitro protein digestibility of the grains. On the other hand, the treatments significantly (P < 0.05) increased the protein solubility of the grains. Obtained results indicate that gamma irradiation might improve the quality characteristics of millet grains, and can be used as a postharvest method for disinfestations and decontamination of millet grains.

Content of phenolic compounds and vitamin C and antioxidant activity in wasted parts of Sudanese citrus fruits

Abstract Phenolic compounds, vitamin C, and the antioxidant activity of wasted parts of citrus (orange, lemon, and grapefruit) fruits were investigated. Ethanolic extracts from whole fruit, peel, and pulp containing seeds of each type of citruses were prepared. Within each type of citrus, results revealed that peels contained a higher amount of phenolic compound, flavonoids, vitamin C, and antioxidant activity than those of their inner wasted parts (pulp and seeds). Peels of grapefruit had the highest total phenolic content followed by lemon and orange, which was found to be 77.3, 49.8, and 35.6 mg of gallic acid equivalent/g of peels, respectively. In contrast, orange peels contain the highest amount of flavonoids (83.3 mg of catechin equivalent/g) and vitamin C (110.4 mg/100 g) compared to the peels of the other citrus fruit used in this study. In general, the high content of antioxidant capacity and activity of citrus waste, particularly the peels, indicated that they may impart health and nutritional benefit when involving in the food industry as a natural antioxidant.

Effect of gamma radiation on storability and functional properties of sorghum grains (Sorghum bicolor L.)

Abstract This study was aimed to evaluate the effect of gamma irradiation at dose levels of 0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 kGy on fungal growth, free fatty acids, in vitro protein digestibility (IVPD), protein solubility, and functional properties of sorghum grains. Results indicated that radiation process enhanced the storability properties. It eliminates the fungal incidence particularly at the higher doses 4.0 and 5.0 kGy, and significantly (p < 0.05) reduced the content of the free fatty acids to the level 3.4–3.2 mg/g. Moreover, a significant increase in IVPD and soluble protein was noticed in irradiated grains as compared to non‐irradiated sample and this increased with the increase in dose; however, maximum IVPD (17.6%) and protein solubility (11.7%) were observed in sorghum grains irradiated at 2.0 kGy. On the other hand, a significant reduction in emulsion capacity was observed after radiation of grains, however, the emulsion activity and stability were stable up to 1.0 kGy. The foaming properties of the radiated sample show no significant change particular at low doses up to 2.0 kGy when they are compared to untreated samples. It can be concluded that low doses of gamma irradiation might improve the storability and quality characteristics of sorghum grains and can be used as an effective alternative postharvest method for preserving and extending the shelf life of sorghum and its products.