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

Evaluation of 93 Accessions of African Yam Bean (Sphenostylis stenocarpa) Grown in Ethiopia for Physical, Nutritional, Antinutritional, and Cooking Properties

African yam bean has immense food and nutrition potential and is resilient to adverse environmental conditions. Despite its potential, the crop is underutilized, which could be attributed to seed hardness (requiring about 6–24 hours of cooking time); and the abundance of antinutrient factors (tannin, phytate, and oxalate). This study evaluated the physical (seed hardness, cooking time) and chemical compositions (crude protein, tannin, phytate, and oxalate) of 93 AYB accessions grown in Ethiopia. The seed hardness of each accession was determined by the compression force and compression time using Texture Analyzer, whereas cooking time was ascertained using Mattson Bean Cooker. The accession’s crude protein level, tannin, oxalate, and phytate were investigated from flour samples using standard laboratory procedures. Highly significant ( $P<0.01$ ) differences were observed for cluster means of compression force, cooking time, and oxalate. The accessions were grouped into three clusters: cluster-II was prominent with 42 accessions, while cluster-I had the least (25). The mean values for compression force ranged from 50.05 N ± 10.25 (TSs-423) to 278.05 N ± 13.42 (TSs-378) whereas compression time varied from 0.35 secs ± 0.02 (TSs-334) to 5.57 secs ± 6.12 (TSs-62B). Cooking time ranged from 127.50 mins ± 2.12 (TSs-82A) to 199.50 mins ± 10.61 (TSs-138B); crude protein ranged from 15.41% ± 0.11 (TSs-269) to 24.51% ± 0.22 (TSs-446). Tannin ranged from 0.61 mg/g  ± 0.02 (TSs-47) to 9.62 mg/g ± 0.03 (TSs-334) likewise, phytate ranged from 0.28 ± 0.01 (TSs-137) to 7.01 ± 0.10 (TSs-3). Accessions TSs-55; TSs-82 showed the lowest oxalate content of 0.21% ± 0.01; 0.21% ± 0.00, respectively. Similarly, TSs-352; TSs-47 revealed the most abundant tannin content of 0.70 ± 0.00 and 0.70 ± 0.07. The correlation analysis revealed a low positive and significant ( $P<0.05$ ) association (r = 0.24) between protein and phytate content.

The prospects of African yam bean: past and future importance

African yam bean (AYB) is an underutilised legume indigenous to West and East Africa with nutritional content comparable to other commonly consumed legumes. The nutrient density of the crop makes it a viable food crop for ameliorating the challenges of malnutrition faced in many developing countries, via direct consumption or fortification and enrichment of less nutritious staples. This review summarises the current body of knowledge on the use of African yam bean as a viable enrichment and fortification crop. Proximate composition and nutritional quality of foods (breakfast diets, traditional foods, snacks and instant noodles) fortified, enriched and complemented with AYB were discussed. The phytochemical and antioxidant potential of the crop were also discussed. Future studies should focus more on awareness towards the deliberate commercialisation of the crop and elevation of its status into a widely - consumed food in all households across developing countries. Adequate experimental design for optimum quantity to be used in the enrichment and fortification of many staples to improve their acceptance among consumers should be put in place. Phytochemical extracts of the bean are also proposed for use in the development of functional foods to mitigate against many lifestyle diseases.

Evaluation of fermented African yam bean flour composition and influence of substitution levels on properties of wheat bread

The composition (proximate, amino acids, in vitro protein digestibility [IVPD]), antinutritional factors (ANFs), functional properties, and antioxidant activity of fermented African yam bean flour (FAYBF) were determined in this study, and the effect of substituting FAYBF on the properties (nutritional, physical, and functional) of bread was investigated. Fermentation significantly (P ≤ 0.05) increased the levels of nutrients, IVPD, total phenolic content (TPC), and antioxidant activity in the flour, with significant (P ≤ 0.05) reduction in ANFs. The water absorption capacity (WAC) and oil absorption capacity (OAC), and swelling capacity of the flour increased after fermentation, while bulk density decreased. Substitution of wheat flour with FAYBF increased WAC and OAC, while peak viscosity decreased. Composite breads had higher nutritional, IVPD, TPC, and antioxidant activity than 100% wheat bread. The study demonstrates that FAYBF could be explored for the preparation of wheat-based bread, with reduced gluten levels. PRACTICAL APPLICATION: Bread is a staple food and this study can assist in increasing the utilization of neglected leguminous crops as well as addressing the challenge of malnutrition, prevalent in developing countries.

Effects of Thermal Processing on the Nutritional, Antinutrient, and In Vitro Antioxidant Profile of Monodora myristica (Gaertn.) Dunal Seeds

Proximate, minerals, and anti-nutrient content of raw Monodora myristica seed and Monodora myristica seeds boiled and roasted for 10, 20, and 30 min, respectively were assessed. In addition, the effects of boiling and roasting for 10, 20, and 30 min on the antioxidant properties of Monodora myristica seed extract were evaluated. Results showed that moisture, ash, fat, and crude protein were significantly reduced by boiling and roasting. Acid and neutral detergent fibres were significantly increased by roasting and boiling, with boiling causing a more significant increase than roasting. Processing resulted in significant decrease in magnesium, potassium, phosphorus, zinc, copper, manganese, and iron while calcium levels were unchanged. Total phenolics levels of raw seeds [(21.94 mg/100 g gallic acid equivalent (GAE)] showed a remarkable decrease (18.64 mg/100 g GAE) when the boiling time was increased to 30 min. Free fraction phenolics increased with thermal processing whereas bound phenolics decreased. Boiling was more effective in reducing anti-nutrients than roasting. Extracts of Monodora myristica seeds possess significant 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis( 3-ethylbenzothiazoline-6-sulphonic acid) free radical scavenging properties in a concentration-dependent manner, and this was significantly reduced after thermal processing. Monodora myristica seed extracts could be pharmaceutically exploited for antioxidant properties, and roasting may be preferred to retain the nutrient composition and antioxidant properties of Monodora myristica seeds.

Elements of kitchen toxicology to exploit the value of traditional (African) recipes: The case of Egusi Okra meal in the diet of HIV+/AIDS subjects

The Egusi Okra soup is a traditional African meal that is considered of high nutritional value and protective against weight loss. We introduce the concept of "kitchen toxicology" to analyse the recipe of the Egusi Okra soup and highlight possible mitigation measures for toxic and/or antinutritional effects in the wide spectrum of health and nutritional needs of HIV+/AIDS subjects. In particular, we focus on toxicants (environmental contaminants, process contaminants, substances leaching from food contact materials) dysregulating the immune status, as well as on interactions between nutrients, contaminants, and/or antinutrients which may lead to secondary/conditioned nutritional deficiencies or imbalances; in their turn, these can modulate the ability to cope with toxicants, and increase nutritional requirements. Recommendations are given for practices preserving the Egusi Okra soup from such risk factors, identifying points of particular attention during meal preparation, from purchase of raw ingredients through to food handling, cooking, storage, and consumption. The Egusi Okra soup is discussed in the context of a diet that is asked to mitigate complications (weight loss, opportunistic infections) and support antiretroviral therapy in African countries with high HIV/AIDS prevalence. The paper discusses how nutritional interventions benefit of the integration of kitchen toxicology practices in everyday life. Toxicological risk assessment is crucial to understand the history and status of the person exposed to or affected by infectious diseases.

Dietary Strategies to Combat Deficiencies of Iron, Zinc, and Vitamin A in Developing Countries: Development, Implementation, Monitoring, and Evaluation

In many developing countries, staple diets are plant-based and consumption of animal products is low. As a result, the intake and bioavailability of iron, zinc, and vitamin A are often poor. Deficiencies of these micronutrients can be prevented by using dietary diversification and modification, a strategy involving changes in food production practices, food selection patterns, and traditional household methods for preparing and processing indigenous foods. Strategies at the food production level include the use of fertilizers, plant breeding, and genetic engineering to enhance the content and bioavailability of micronutrients in plant-based staples and increase the yield of indigenous edible wild plants. Household strategies involve small-livestock production, aquaculture, gardening projects, and changes in certain food preparation and processing practices designed to alter the content of absorption modifiers in the diet, such as soaking, germination, fermentation, and enrichment. This review also describes how these household strategies can best be incorporated into existing food consumption patterns, and how their impact on the nutrient adequacy of the diets can be assessed. the steps necessary to test the acceptability of the modified recipes, to identify potential barriers to their adoption, and to implement them in the community are discussed, using an example from rural Malawi. Finally, methods of monitoring the progress and evaluating the impact of the dietary strategies in short- and long-term studies are included.

Effects of Processing (Boiling and Roasting) on the Nutritional and Antinutritional Properties of Bambara Groundnuts (Vigna subterranea [L.] Verdc.) from Southern Kaduna, Nigeria

This research analyzed the effect of processing (boiling and roasting) on the proximate, antinutrient, and mineral composition of Vigna subterranea seeds. The proximate composition analysis showed significant difference (P<0.05) between the levels of crude lipid, crude fiber, gross energy, carbohydrate, and moisture content in the raw and processed V. subterranea. However, no significant difference (P<0.05) was observed in protein content of processed V. subterranea as compared to the raw seeds. Analyses of antinutrient composition show that processing significantly reduced the levels of oxalate, tannins, phytate, trypsin inhibitor, and hydrogen cyanide contents of V. subterranea. While magnesium, potassium, and phosphorus were the most abundant macrominerals in V. subterranea, zinc was the most abundant micromineral. Correlation analysis revealed that the levels of crude protein, ash, moisture, and lipid were negatively affected by phytate, tannins, and oxalate. The results, therefore, suggest that processing significantly lowered the levels of antinutrients in V. subterranea, thereby making it safer for consumption.

Role of oxate, phytate, tannins and cooking on iron bioavailability from foods commonly consumed in Mexico

The objectives of this research were to assess the bioavailability of iron in foodstuffs found in the Mexican diet, to provide data on the content of iron absorption inhibitors present in plant origin products and to assess the inhibitory effect of these compounds and of cooking on iron bioavailability; therefore, total content and bioavailable iron, tannins, phytic and oxalic acid were determined in vegetables, cereals, legumes and animal products, before and after cooking. Vegetables, although rich in iron, have poor iron bioavailability and a high content of inhibitory factors; cooking reduced the content of iron and inhibitory factors, whereas in animal products the treatment of cooking did not significantly reduce it. Iron bioavailability, phytate content and the phytate to iron molar ratio predicted poor iron bioavailability and, therefore, a negative impact on the nutritional status of people who rely on them as staple foods could be expected.

Análise dos teores de ácidos cianídrico e fítico em suplemento alimentar: multimistura

OBJETIVO: Este estudo objetivou quantificar o teor de ácido cianídrico em folhas de mandioca, que receberam tratamento prévio antes da secagem, e a concentração de ácido fítico na multimistura submetida à cocção úmida. MÉTODOS: Utilizou-se a multimistura produzida pela Pastoral da Criança da cidade de Pelotas (RS), constituída por: farelos de trigo (30%) e arroz (30%): farinhas de milho (15%) e trigo (10%); pós de casca de ovo (5%), de folha de mandioca (5%) e de sementes (5%, abóbora ou girassol). Foi realizada orientação ao fornecedor da folha de mandioca sobre a forma recomendada de preparo antes da secagem. RESULTADOS: O conteúdo de ácidos cianídrico e fitatos no suplemento alimentar foram respectivamente de 85mg.kg-1 e 35.90mg.100-1. CONCLUSÃO: Verificou-se que a mudança na forma de secagem das folhas de mandioca foi eficiente para a redução de glicosídeos cianogênicos, e que o processo de torrefação dos ingredientes foi suficiente para produzir a redução de ácido fítico da multimistura aos níveis preconizados pela legislação, não sendo observadas diferenças estatisticamente significantes quando comparadas as amostras que também foram tratadas com calor úmido.

Influence of germination and fermentation on bioaccessibility of zinc and iron from food grains

OBJECTIVE AND DESIGN

Food grains such as green gram, chickpea and finger millet are often subjected to traditional processing involving germination and fermentation. This study was designed to assess the effect of germination of these grains on the bioaccessibility of zinc and iron. The effect of fermentation of a cereal-pulse combination as encountered in the preparation of breakfast dishes - idli, dosa and dhokla - on the same was also evaluated. Bioaccessibility measurement was made employing an in vitro simulated digestion method.

RESULT

Zinc bioaccessibility was significantly decreased by germination (48 h) of finger millet (38%) and green gram (44%), while iron bioaccessibility was increased by 62% (green gram), 39% (chickpea) and 20% (finger millet), concomitant with a reduction in tannin content. A fermented batter of rice+black gram - 2:1 (idli) and 3:1 (dosa) - had higher bioaccessibility values for zinc (71 and 50%, respectively), while iron bioaccessibility values were increased in these cases of fermentation to an even greater extent, namely 277 and 127%, respectively. Zinc and iron bioaccessibility was not improved by fermentation of the combination of chickpea, green gram, black gram and rice (1:1:0.5:0.5; dhokla). A fermentation of cereal-legume combinations of idli and dosa batter significantly reduced both phytate and tannin, while in the case of dhokla batter there was a continued significant presence of phytate associated with additional legumes - chickpea and green gram.

CONCLUSION

Germination of food grains improved the bioaccessibility of iron but not that of zinc. Fermentation of a batter of cereal-pulse combination in the preparation of idli and dosa enhanced the bioaccessibility of both zinc and iron, but not that of the combination used for the preparation of dhokla.

Adições crescentes de ácido fítico à dieta não interferiram na digestibilidade da caseína e no ganho de peso em ratos

O crescente consumo de alimentos de origem vegetal, sejam como fontes protéicas com baixo teor de gordura ou como fontes de fibras, tem acrescido à dieta humana o ácido fítico. Devido à sua carga altamente negativa, o ácido fítico tem sido visto como componente de ação antinutricional capaz de quelar minerais bivalentes, proteínas e amido, podendo comprometer a biodisponibilidade destes nutrientes. No presente estudo investigou-se a influência da adição de ácido fítico à dieta de caseína, em concentrações iguais ou até oito vezes superiores àquelas encontradas no feijão-comum Phaseolus vulgaris, cultivar IAC-Carioca (14,7mg de ácido fítico/g feijão cru), durante período experimental de dez dias, sobre os índices nutricionais Ganho de Peso, Quociente de Eficiência da Dieta, Quociente de Eficiência Protéica Líquida, Digestibilidade Aparente e Digestibilidade Verdadeira. Trinta e seis ratos machos SPF da linhagem Wistar, recém-desmamados, divididos em grupos experimentais com seis ratos cada, foram alimentados com dieta purificada AIN-93G isenta de ácido fítico (Controle) e dietas teste AIN-93G acrescidas de 218, 436, 872 e 1744mg de ácido fítico/kg de dieta (Tratamentos). Os ganhos de peso (g) e os índices de qualidade dietética e protéica não apresentaram diferença estatística (p>0,05), e os valores médios entre os grupos foram: Ganho de Peso: 59,5 ± 5,0g; Quociente de Eficiência da Dieta: 0,39 ± 0,01; Quociente de Eficiência Protéica Líquida: 3,64 ± 0,12; Digestibilidade Aparente: 92,7 ± 1,1% e Digestibilidade Verdadeira: 94,4 ± 0,9%. Os resultados demonstraram que nas condições experimentais utilizadas, o ácido fítico não foi capaz de alterar o valor nutritivo da caseína.

Antinutrients and digestibility (in vitro) of soaked, dehulled and germinated cowpeas

Phytic acid, polyphenols, protein and starch digestibility (in vitro) in two varieties, namely CS-46 and CS-88, of soaked, dehulled and germinated cowpeas were determined. Soaking for 12 hours, dehulling of soaked seeds and germination for different time periods (24, 36 and 48 h) contributed significantly in reducing the phytic acid and polyphenol content of cowpeas. Removal of seed coat (dehulling) of soaked cowpeas reduced the polyphenols by 70-71%. Soaking (12 h) brought about an improvement in protein and starch digestibility which further increased after dehulling. Progressive increase in digestibility (protein and starch) was noticed, with an increase in germination period. Dehulling of soaked seeds was most effective in reducing the polyphenolic content, and germination in enhancing protein and starch digestibility.