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Byline: T. C. Mosha (1), R. D. Pace (2), S. Adeyeye (2), H. S. Laswai (1), K. Mtebe (1) Keywords: [alpha]-carotene; [beta]-Carotene; Blanching; Provitamin A carotenoids; Shade drying; Sun drying; Total carotenoids; Vitamin A activity Abstract: The [alpha]-carotene, [beta]-carotene and total provitamin A carotenoids and the effect of traditional processing practices on the retention of these provitamins were studied using amaranth, cowpea, peanut, pumpkin and sweet potato leaves. Results of this study indicated that the content of total carotenoids, [beta]-carotene and [alpha]-carotene were in the range of 26.79--44.74 mg, 4.16--19.12 mg, and 0.99--10.26 mg per 100 g of dry vegetables, respectively. The vitamin A activities were 4.042, 3.124, 0.829, 2.025 and 1.581 mg RE per 100 g of dry amaranth, cowpea, peanut, pumpkin and sweet potato leaves, respectively. The traditional processing practices of sun drying and storage in ventilated containers resulted in a significant (p Author Affiliation: (1) Department of Food Science and Nutrition, Sokoine University of Agriculture, P.O. Box 3006, Morogoro, Tanzania (2) Department of Home Economics, Tuskegee University, 36088, Tuskegee, AL, U.S.A. Article History: Registration Date: 26/05/2006 Received Date: 04/10/1994

Purpose Child undernutrition is a persistent problem in Africa, especially in areas where the poor largely depend on starchy staples with limited access to diverse diets. The purpose of this study was to determine the protein quality, growth and rehabilitating potential of composite foods made from quality protein maize.Design/methodology/approach Four composite diets were prepared from quality protein maize, namely quality protein maize-soybeans; quality protein maize-soybeans-cowpeas; quality protein maize-soybeans-common beans and quality protein maize alone. A fifth diet was prepared from common maize alone. The control diet (Chesta®) was made from maize, soybeans, fish, bone and blood meal. The formulations were made to meet the greatest amino acid score and the desired amount of energy and fat according to the FAO/WHO (1985) recommendation for pre-school children. Albino rats were used in evaluating the protein quality of the formulations.Findings The food intake was significantly different (p < 0.05) among diets; with a trend of intake decreasing from quality protein maize-based to conventional maize alone diets (apart from the control diet). Protein efficiency ratio and net protein ratio varied significantly (p < 0.05) across the experimental diets. Protein digestibility-corrected amino acid score (PDCAAS) was 80 per cent (quality protein maize-soybeans-cowpeas), 87 per cent (quality protein maize-soybeans), 103 per cent (common maize alone), 98 per cent (quality protein maize), 80 per cent (quality protein maize-soybeans-common beans) and 53 per cent (control).Research limitations/implications Two diets, namely quality protein maize-soybeans-common beans and quality protein maize-soybeans-cowpeas, showed the greatest potential to support growth and rehabilitation of undernourished rats. Human trial is proposed to validate the findings.Originality/value Despite adoption of quality protein maize in several parts of the country, there are no studies that have been done to determine the potential of quality protein maize to support optimal growth and rehabilitation of undernourished children. The objective of this study was, therefore, to evaluate the protein quality, growth and rehabilitating potential of composite foods made from quality protein maize. [ABSTRACT FROM AUTHOR]

Traditional alcoholic beverages of Tanzania play an important role in the daily social, economic, nutritional and cultural life of the people. Production, quality and changes in quality attributes during ambient temperature storage were investigated in traditional Tanzanian beers (Mbege and Komoni) and wines (Mnanasi, Wanzuki and Mofru). The quality attributes of the alcoholic beverages indicated that pH levels were in the range of 4.15-4.20 and 3.9-5.5 for the beers and wines respectively. Total, fixed and volatile acidity in the beers were in the range of 0.41-0.62, 0.28-0.38 and 0.06-0.09 g/100 mL respectively while in the wines acidity levels were in the range of 0.23-0.66, 0.13-0.33 and 0.05-0.06 g/100 mL for the total, fixed and volatile acidity respectively. Concentration of total solids in the beers ranged between 7.00 and 12.80 degrees Brix while in the wines ranged between 3.45 and 6.65 degrees Brix. Specific gravity of the beers ranged between 1.0097 and 1.0374 while for wines the specific gravity was lower, ranging between 0.9971 and 0.9989. Alcohol concentration was higher in wines (range 3.84-9.75 g/100 mL) than in beers (range 1.72-2.76 g/100 mL). Storage of the beverages under ambient temperatures for various lengths of time resulted in significant (P < 0.05) increase in total acidity, volatile acidity and alcohol content and decrease in the total solids and specific gravity. Mbege and Komoni beers indicated the highest rates of deterioration with total acid production rates of 0.3774 g/100 mL and 0.0914 g/100 mL per hour respectively. Wines were more stable during storage than beers, with Mofru wine being the most stable. The rates of total acid production per hour were Mnanasi (0.0196 g/100 mL), Wanzuki (0.0047 g/100 mL) and Mofru (0.0005 g/100 mL). Use of low brewing technologies involving uncontrolled fermentation, unsanitary conditions and use of rudimentary equipment for processing, packaging and storage resulted in beers and wines of low quality and short shelf-life. To foster commercial exploitation of the products, there is a need to develop appropriate small and medium-level brewing technologies that will improve the quality of the traditional alcoholic beverages and extend their shelf-life through hygienic and controlled processing, packaging, and storage.

Proximate composition, energy, mineral and vitamin contents and the effect of blanching methods and times on the trypsin and chymotrypsin inhibitor activities were studied using cabbage, collard, turnip, peanut, and sweet potato leaves. Results of this study indicated that, crude protein, crude fat, carbohydrate and ash contents were in the range of 15.5-25.6%, 1.4-6.5%, 60.4-73.1% and 6.8-7.5%, respectively. Total dietary fiber was lowest in cabbage (28.2 g/100 g) and highest in the collard leaves (43.1%) while energy content per 100 g of vegetables was highest in sweet potato leaves (402 kcal) and lowest in cabbage (379 kcal). The mineral content per 100 g of vegetables were in the range of 33.4-249.8 mg, 241.2-471.2 mg, 12.1-75.1 mg, 14.9-98.9 mg, 0.5-3.5 mg and 0.9-3.1 mg for Ca, K, Na, Mg, Fe and Zn, respectively. For ascorbic acid, riboflavin, thiamin and total carotenoids, concentrations in 100 g of vegetables were in the range of 45.1-112.7 mg, 0.2-0.3 mg, 0.3-0.8 mg and 2.0-7.3 mg, respectively. The trypsin inhibitory activity per gram of the vegetables was highest in collard (60.1 TIU/g) and lowest in peanut leaves (41.0 TIU/g). Chymotrypsin inhibitor activity was highest in the peanut (69.6 CIU/g) but lowest in the collard leaves (48.0 CIU/g). Both trypsin and chymotrypsin inhibitor activities were significantly (p < 0.05) reduced by most of the treatments in either the conventional or microwave blanching methods. In the conventional blanching method, trypsin inhibitor activity was reduced by 0.5, 6.8, 11.9, 9.0 and 19.3 percent in cabbage, collard, turnip, sweet potato and peanut leaves, respectively, when the vegetables were blanched for 2.5 minutes but after blanching for 10 minutes, the trypsin inhibitor activity was reduced by 29.7, 34.9, 54.3, 52.3 and 65.6 percent in cabbage, collard, turnip, sweet potato and peanut greens, respectively. For the microwave oven blanching, trypsin inhibitor activity was reduced by 3.8, 3.3, 32.7, 5.0 and 9.5 percent in cabbage, collard, turnip, sweet potato and peanut leaves, respectively when the vegetables were blanched for 30 seconds. When blanched for 60 seconds, trypsin inhibitor activity was reduced by 16.2, 45.8, 46.2, 51.0 and 42.4 percent in cabbage, collard, turnip, sweet potato and peanut greens, respectively. Similar trends in the reduction of chymotrypsin inhibitor activity were observed when the vegetables were conventionally blanched for 2.5, 5 and 10 minutes and when blanched by microwave oven for 30, 45 and 60 seconds. Based on the results of this study, the vegetables were good dietary sources of minerals, vitamins, carbohydrate and proteins. Also, blanching was an effective method for reducing the trypsin and chymotripsin inhibitor activities in the leafy vegetables, however, further investigation on the heating times for both conventional and microwave blanching methods is suggested.