Abstract: Acha and Iburu flours were singly subjected to sourdough fermentation with previously selected autochthonous starters. Sourdoughs were used (30%, wt/wt) as aroma carriers and acidifiers during short time fermentation with the addition of baker's yeast. Acha and Iburu sourdough breads were compared to wheat sourdough bread started with the same strains and to breads made with the same formula but using baker's yeast alone. During Acha and Iburu sourdough fermentations, starter lactic acid bacteria reached almost the same cell density found in wheat sourdoughs. Acidification was more intense. Iburu sourdough bread had the highest total titratable acidity, the lowest pH, and contained the highest levels of free amino acids and phytase activity. The values of in vitro protein digestibility did not differ between Acha sourdough and wheat sourdough breads, while Iburu sourdough bread showed a slightly lower value. Acha and Iburu sourdough breads showed lower specific volume and higher density with respect to wheat sourdough breads. Nevertheless, Acha and Iburu sourdough breads were preferred for hardness and resilience. As shown by sensory analysis, Acha and especially Iburu sourdough breads were appreciated for color, acid taste and flavor, and overall acceptability. Practical Application: This study was aimed at evaluating the technological and nutritional properties of the African cereals Acha and Iburu. Sourdough fermentation and the use of selected starters increased the nutritional and sensory qualities and the potential application for bakery industry. 相似文献
Background: Dietary patterns are often considered as one of the main causes of non-communicable diseases worldwide. It is of utmost importance to study dietary habits in developing countries since this work is scarce.
Objective: To summarize the most recent research conducted in this field in African countries, namely the most used methodologies and tools.
Methods: A systematic review was conducted on MEDLINE®/PubMed, aiming to identify scientific publications focused on studies of dietary intake of different African populations, in a ten-year period. Papers not written in English/Portuguese/Spanish, studies developed among African people but not developed in African countries, studies aiming to assess a particular nutrient/specific food/food toxin and studies that assessed dietary intake among children were excluded.
Findings: Out of 99 included studies, the 24-hour recall and the food-frequency questionnaire were the most used dietary intake assessment tools, used to assess diet at an individual level. It was also observed that often country-unspecific food composition databases are used, and the methodologies employed are poorly validated and standardized.
Conclusions: There is an emergent need to improve the existing food databases by updating food data and to develop suitable country-specific databases for those that do not have their own food composition table. 相似文献
The catalytic effect of inorganic species, within the ash, on the CO2 gasification of three South African coals containing similar carbon-structural properties (elemental, structural and petrographical properties) was assessed. The reactivity of the coals with a particle size between 150 and 250 μm was determined in a thermo gravimetric analyser. The reactivity was measured at temperatures between 900 and 1000 °C, pressures between 1 and 10 bar, and fractions of CO2 between 10 and 30%. For the selected coals, the reactivity decreased with ash content, and was found to be dependent on the composition of the ash. Specifically, the reactivity increased with calcium and magnesium content and alkali index. 相似文献
Enzymatic hydrolysate of African yam bean seed protein isolate was prepared by treatment with alcalase. The hydrolysate was further fractionated into peptide sizes of <1, 1-3, 3-5 and 5-10 kDa using membrane ultrafiltration. The protein hydrolysate (APH) and its membrane ultrafiltration fractions were assayed for in vitro antioxidant activities. The <1 kDa peptides exhibited significantly better (p < 0.05) ferric reducing power, diphenyl-1-picryhydradzyl (DPPH) and hydroxyl radical scavenging activities when compared to peptide fractions of higher molecular weights. The high activity of <1 kDa peptides in these antioxidant assay systems may be related to the high levels of total hydrophobic and aromatic amino acids. In comparison to glutathione (GSH), the APH and its membrane fractions had significantly higher (p < 0.05) ability to chelate metal ions. In contrast, GSH had significantly greater (p < 0.05) ferric reducing power and free radical scavenging activities than APH and its membrane fractions. The APH and its membrane fractions effectively inhibited lipid peroxidation, results that were concentration dependent. The activity of APH and its membrane fractions against linoleic acid oxidation was higher when compared to that of GSH but lower than that of butylated hydroxyl toluene (BHT). The results show potential use of APH and its membrane fractions as antioxidants in the management of oxidative stress-related metabolic disorders and in the prevention of lipid oxidation in food products. 相似文献
The shoulder, loin and leg from P-class pork carcasses were used to determine the nutrient composition of both raw and cooked cuts. Significantly lower fat content were observed in the current study for the leg (5.21 g/100 g) and loin (6.99 g/100 g) compared to the shoulder cut (10.32 g/100 g). The overall percentage fat for all three cuts was less than 10% which is recommended by the South African Heart Mark. The cooked loin cut contained the most protein (27.50 g/100 g) of the three cooked cuts. When compared to other meat products (beef, mutton and chicken) it is clear that pork is a good source of B vitamins, especially vitamin B3. The cooked loin cut contained the least vitamin B1 (0.22 mg/100 g), B2 (0.02 mg/100 g) but the most vitamin B3 (7.09 mg/100 g), of the three cooked cuts. The 100 g cooked shoulder, loin and leg cuts provide on average 40.11% protein, 5.19% magnesium, 3.37% calcium, 24.29% phosphorus, 18.22% zinc, 22.33% iron and 22.50% vitamin B1, 2.57% vitamin B2 and 42.6% vitamin B3 of Recommended Daily Allowances for males, age 25–50. Energy from a 100 g portion provides 5.81% of the Recommended Daily Allowances. To conclude, the pork cuts are undoubtedly a good source of nutrients that is required for good health because it is high in protein, have a low fat content and are a nutrient-packed choice for the family and compares favourably with the fat, energy, and cholesterol content of many other meats and poultry. 相似文献
A study was conducted to analyse market-regulated heavy metals (lead, mercury and cadmium), organochlorine pesticides and total polychlorinated biphenyls (PCBs) in samples of 38 farmed fish comprising Nile tilapia (Oreochromis niloticus) (20 samples) and African catfish (Clarias gariepinus) (18 samples) from ten selected fish farms in Uganda. The goal of this case study was to understand the safety of aquaculture products from Sub-Saharan Africa. Lead was detected in all the 38 samples (maximum = 1.08 mg kg?1 (dry weight)), mercury in 31 out of 38 samples (maximum = 0.35 mg kg?1 (dry weight)), and cadmium in two samples (maximum = 0.03 mg kg?1 (dry weight)). Total levels of PCBs were below the limit of detection of 0.02 mg kg?1 (wet weight) in all the samples. Traces of 4,4′-dichloro-diphenyldichloroethylene (DDE) were detected in ten out of 38 samples (maximum = 0.01 mg kg?1 (wet weight)) making it the most prevalent organochlorine pesticide. Other pesticides detected were: 4,4′-dichloro-diphenyl-trichloroethane (DDT) and endosulfan sulphate, which were found in one fish sample (both 0.002 mg kg?1 (wet weight)). There was no statistically significant difference between the levels of lead and mercury in catfish and tilapia (t-test at p = 0.05). More catfish samples (eight) contained DDE as compared with tilapia (two). Cadmium, DDT and endosufan sulphate were only detected in catfish implying that catfish is more prone to contamination than tilapia. The levels of contaminants were below the US Food and Drug Administration (USFDA) action levels and European Union maximum residue limits (MRLs), indicating that such fish have the potential for export to these markets. 相似文献
Julie E. Braciszewski, recipient of the APA/APAGS Award for Distinguished Graduate Student in Professional Psychology, is cited for her noteworthy efforts to decrease mental health and academic service disparities among low-income, urban African American youth. Braciszewski recognizes that educational achievement is the clearest and most reliable route to breaking the cycle of persistent poverty. She has substantially contributed to research in understanding the needs of inner city children and the processes that contribute to their risk and success. In addition to the citation, a biography and selected bibliography of Braciszewski's works are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
A key challenge for managers of water utilities in developing countries is to provide services to the rising urban population in a financially sustainable manner. The paper examines the management of water services in an African city which piloted service differentiation and pricing. Among the key findings was that substantial improvement in the provision of water services to the urban poor was attained. Cost recovery was achieved through innovative structuring of public/private partnerships, an appropriate pricing policy, and flexible payment systems. The project demonstrates that (a) by structuring service delivery with appropriate pricing, utilities could serve more customers (including people living in informal settlements) at affordable cost and achieve financial sustainability, and (b) service differentiation and appropriate pricing has the potential to improve urban water services in low-income countries. 相似文献