Trans-β-carotene, selected mineral content and potential nutritional contribution of 12 sweetpotato varieties

Implementing micronutrient fortification programs as a potential practical contribution to achieving sustainable diets

Due to sustainability concerns related to current diets and environmental challenges, it is crucial to have sound policies to protect human and planetary health. It is proposed that sustainable diets will improve public health and food security and decrease the food system's effect on the environment. Micronutrient deficiencies are a well-known major public health concern. One-third to half of the world's population suffers from nutrient deficiencies, which have a negative impact on society in terms of unrealised potential and lost economic productivity. Large-scale fortification with different micronutrients has been found to be a useful strategy to improve public health. As a cost-effective strategy to improve micronutrient deficiency, this review explores the role of micronutrient fortification programmes in ensuring the nutritional quality (and affordability) of diets that are adjusted to help ensure environmental sustainability in the face of climate change, for example by replacing some animal-sourced foods with nutrient-dense, plant-sourced foods fortified with the micronutrients commonly supplied by animal-sourced foods. Additionally, micronutrient fortification considers food preferences based on the dimensions of a culturally sustainable diet. Thus, we conclude that investing in micronutrient fortification could play a significant role in preventing and controlling micronutrient deficiencies, improving diets and being environmentally, culturally and economically sustainable.

Essential Mineral Elements and Potentially Toxic Elements in Orange-Fleshed Sweet Potato Cultivated in Northern Ethiopia

This study investigated the influence of the agro-climatic environment of Northern Ethiopia on the content of essential mineral elements of selected orange-fleshed sweetpotato genotypes, the potential contribution of each genotype's essential mineral elements to the recommended dietary allowance, and the potential risk to human health from the accumulation of potentially toxic elements in the tuberous roots of the studied genotypes. The results showed consistent interspecific variations in the content of essential mineral elements among the studied orange-fleshed sweetpotato genotypes, as well as important intraspecific differences, which could depend on the variations in soil mineral and organic matter content, rainfall, temperature, as well as interactions between genotype and environment. The investigated genotypes, especially Kulfo, Ininda, Gloria, and Amelia, can provide an amount of several essential mineral elements high enough to meet 100% of the recommended dietary allowance for all age groups ≤8 years. The mean content of potentially toxic elements in tuberous roots and their daily intake values were within the recommended permissible levels; likewise, no health risk was associated with the consumption of these genotypes for Cr, As, and Pb. However, Al, Cd, Cu, Fe, Mn, and Ni is > 1, consumption imposes health risks based on daily accumulation.

Improving nutrition through biofortification-A systematic review

Nutritious foods are essential for human health and development. However, malnutrition and hidden hunger continue to be a challenge globally. In most developing countries, access to adequate and nutritious food continues to be a challenge. Although hidden hunger is less prevalent in developed countries compared to developing countries where iron (Fe) and zinc (Zn) deficiencies are common. The United Nations (UN) 2nd Sustainable Development Goal was set to eradicate malnutrition and hidden hunger. Hidden hunger has led to numerous cases of infant and maternal mortalities, and has greatly impacted growth, development, cognitive ability, and physical working capacity. This has influenced several countries to develop interventions that could help combat malnutrition and hidden hunger. Interventions such as dietary diversification and food supplementation are being adopted. However, fortification but mainly biofortification has been projected to be the most sustainable solution to malnutrition and hidden hunger. Plant-based foods (PBFs) form a greater proportion of diets in certain populations; hence, fortification of PBFs is relevant in combating malnutrition and hidden hunger. Agronomic biofortification, plant breeding, and transgenic approaches are some currently used strategies in food crops. Crops such as cereals, legumes, oilseeds, vegetables, and fruits have been biofortified through all these three strategies. The transgenic approach is sustainable, efficient, and rapid, making it suitable for biofortification programs. Omics technology has also been introduced to improve the efficiency of the transgenic approach.

Analysis of the Nutritional Composition and Drought Tolerance Traits of Sweet Potato: Selection Criteria for Breeding Lines

Sweet potato is an important world staple with the potential to address hunger and malnutrition. The Agricultural Research Council of South Africa has led sweet potato breeding efforts in the country since 1952 and released several important cultivars. More detailed quality assessments are necessary in addition to general breeding criteria. The present study investigated sweet potato cultivars and elite clones for (1) their nutritional composition; (2) biochemical reaction to drought stress; (3) correlate biochemical reaction to root yield for possible identification of screening methods for drought tolerance in sweet potato. Orange-fleshed cultivars, in particular Bophelo, had superior contents of Fe, Zn, Mg, Ca, Mn, and dietary fiber. Cream-fleshed cultivars, particularly Ndou, were higher in starch and carbohydrate. When sweet potato cultivars were subjected to drought stress, significant changes were noted in most antioxidant enzymes, chlorophyll and proline concentrations, and ¹³C discrimination. All of these showed significant correlations with root yield. For screening of drought tolerance, the determination of nitrate reductase, proline, and chlorophyll concentrations at 60 days after planting are recommended. Ndou was less affected by drought stress. Bophelo and Ndou, which are gaining popularity on the informal market, have superior nutritional value and are good cultivar choices for food security and addressing malnutrition.

Design and Nutrient Analysis of a Carotenoid-Rich Food Product to Address Vitamin A and Protein Deficiency

Worldwide undernutrition affects over 820 million individuals and is the underlying cause of over 50% of all childhood deaths. Sweet potatoes have been promoted to address vitamin A (vitA) deficiency, with a single, orange-fleshed sweet potato (OFSP) providing enough vitA, as β-carotene, to meet daily needs. However, the bioavailability of β-carotene is dependent on the presence of dietary fat, which is not provided by OFSP, and it lacks some essential amino acids. Therefore, in an attempt to create a food product that meets daily vitA requirements with adequate bioavailability and complete protein, we designed and assessed a sweet potato, peanut paste, and legume product. The final food product formulation, developed through computer modeling, resulted in a 65/5/35 (w/w/w) formulation in a 250 g serving and ~330 kcal. We then confirmed the nutrient content of macronutrients, and essential amino acids, zinc, and iron contents. Total β-carotene was assessed by HPLC and was lower than predicted through computer modeling, likely due to losses through thermal processing and/or degradation from storage. The results of this project indicate that the three ingredients can be combined into a single 250 g food product to provide >300 kcal energy, complete protein, and micronutrients in a more bioavailable form.

Potential of pumpkin to combat vitamin A deficiency during complementary feeding in low and middle income countries: variety, provitamin A carotenoid content and retention, and dietary reference intakes

The risk of child vitamin A deficiency (VAD) in low and middle income countries (LMICs) begins during the age range of complementary feeding (6-24 months), when children are fed complementary foods (CFs) deficient in vitamin A. However, pumpkin, a source of provitamin A carotenoids (PVACs) is widely cultivated in LMICs, but underutilized as a complementary food. Moreover, when consumed by humans, PVACs are bioconverted to retinol, the active form of vitamin A used by the body. This study evaluated the potential of pumpkin toward combating VAD by reviewing varieties of pumpkin cultivated in LMICs and their provitamin A carotenoid (PVAC) content; retention of PVACs in pumpkin during processing it as a CF; and the extent to which a CF prepared from pumpkin may meet the dietary reference intakes (DRIs) for vitamin A for children aged 6-24 months old. Pumpkin may combat VAD because the varieties cultivated have high β-carotene content, it is a provitamin A biofortifiable food crop, and 100% retention of PVACs was observed when processed using home cooking methods. Feeding less than 50 g of cooked pumpkin per day meets 100% of the recommended dietary allowance (RDA) and adequate intake (AI) of vitamin A for children 6 to 24 months old. Consumption of pumpkin may be used to complement vitamin A supplementation, fortification, and diversification of CFs with animal source foods. For better yield of pumpkin in LMICs, nutrition sensitive agricultural programmes such as biofortification and agronomic management of pumpkin need to be promoted and supported.

Fighting Iron-Deficiency Anemia: Innovations in Food Fortificants and Biofortification Strategies

Iron deficiency remains one of the main nutritional disorders worldwide and low iron intake and/or bioavailability are currently the major causes of anemia. To fight this public health problem, the scientific challenge is to find an iron form with sufficient bioavailability to increase its levels in humans through food fortification. In turn, biofortification appears as a comparatively advantageous and bearable strategy for the delivery of vitamins and other micronutrients for people without access to a healthy and diverse diet. This approach relies on plant breeding, transgenic techniques, or agronomic practices to obtain a final food product with a higher iron content. It is also known that certain food constituents are able to favor or inhibit iron absorption. The management of these compounds can thus successfully improve the absorption of dietary iron and, ultimately, contribute to fight this disorder present all over the world. This review describes the main causes/manifestations of iron-deficiency anemia, forms of disease prevention and treatment, and the importance of a balanced and preventive diet. A special focus was given to innovative food fortification and biofortification procedures used to improve the iron content in staple food crops.

Biofortified Crops for Combating Hidden Hunger in South Africa: Availability, Acceptability, Micronutrient Retention and Bioavailability

In many poorer parts of the world, biofortification is a strategy that increases the concentration of target nutrients in staple food crops, mainly by genetic manipulation, to alleviate prevalent nutrient deficiencies. We reviewed the (i) prevalence of vitamin A, iron (Fe) and zinc (Zn) deficiencies; (ii) availability of vitamin A, iron and Zn biofortified crops, and their acceptability in South Africa. The incidence of vitamin A and iron deficiency among children below five years old is 43.6% and 11%, respectively, while the risk of Zn deficiency is 45.3% among children aged 1 to 9 years. Despite several strategies being implemented to address the problem, including supplementation and commercial fortification, the prevalence of micronutrient deficiencies is still high. Biofortification has resulted in the large-scale availability of βcarotene-rich orange-fleshed sweet potatoes (OFSP), while provitamin A biofortified maize and Zn and/or iron biofortified common beans are at development stages. Agronomic biofortification is being investigated to enhance yields and concentrations of target nutrients in crops grown in agriculturally marginal environments. The consumer acceptability of OFSP and provitamin A biofortified maize were higher among children compared to adults. Accelerating the development of other biofortified staple crops to increase their availability, especially to the target population groups, is essential. Nutrition education should be integrated with community health programmes to improve the consumption of the biofortified crops, coupled with further research to develop suitable recipes/formulations for biofortified foods.

Iron Biofortification of Staple Crops: Lessons and Challenges in Plant Genetics

Plants are the ultimate source of iron in our diet, either directly as staple crops and vegetables or indirectly via animal fodder. Increasing the iron concentration of edible parts of plants, known as biofortification, is seen as a sustainable approach to alleviate iron deficiency which is a major global health issue. Advances in sequencing and gene technology are accelerating both forward and reverse genetic approaches. In this review, we summarize recent progress in iron biofortification using conventional plant breeding or transgenics. Interestingly, some of the gene targets already used for transgenic approaches are also identified as genetic factors for high iron in genome-wide association studies. Several quantitative trait loci and transgenes increase both iron and zinc, due to overlap in transporters and chelators for these two mineral micronutrients. Research efforts are predominantly aimed at increasing the total concentration of iron but enhancing its bioavailability is also addressed. In particular, increased biosynthesis of the metal chelator nicotianamine increases iron and zinc levels and improves bioavailability. The achievements to date are very promising in being able to provide sufficient iron in diets with less reliance on meat to feed a growing world population.

Review on nutritional composition of orange-fleshed sweet potato and its role in management of vitamin A deficiency

A wide variety of the roots and tubers plays a major role in human diet, animal feed, and industrial raw materials. Sweet potatoes (SPs) play an immense role in human diet and considered as second staple food in developed and underdeveloped countries. Moreover, SP production and management need low inputs compared to the other staple crops. The color of SP flesh varied from white, yellow, purple, and orange. Scientific studies reported the diversity in SP flesh color and connection with nutritional and sensory acceptability. Among all, orange-fleshed sweet potato (OFSP) has been attracting food technologists and nutritionists due to its high content of carotenoids and pleasant sensory characteristics with color. Researchers reported the encouraging health effects of OFSP intervention into the staple food currently practicing in countries such as Uganda, Mozambique, Kenya, and Nigeria. Scientific reviews on the OFSP nutritional composition and role in vitamin A management (VAM) are hardly available in the published literature. So, this review is conducted to address the detailed nutritional composition (proximate, mineral, carotenoids, vitamins, phenolic acids, and antioxidant properties), role in vitamin A deficiency (VAD) management, and different food products that can be made from OFSP.

Composição mineral em genótipos de batata-doce de polpas coloridas e adequação de consumo para grupos de risco

Resumo Este estudo objetivou quantificar minerais presentes em genótipos de batata-doce de polpa colorida, selecionados e cultivados pela Embrapa (Empresa Brasileira de Pesquisa Agropecuária), no sul do Rio Grande do Sul, bem como verificar o percentual de adequação de consumo em grupos de risco nutricional. Genótipos de batata-doce cultivados no Banco Ativo de Germoplasma ‒ polpa branca (Rubissol, ILS 12, ILS 10, ILS 24); polpa creme (Cuia, ILS 03, ILS 44); polpa amarela/laranja (Amélia e Beauregard); polpa roxa (ILS 56, ILS 16 e ILS 71) ‒ foram analisados em triplicata. Os minerais foram quantificados por espectrometria de absorção atômica e os resultados foram expressos em miligrama do mineral correspondente a 100 g-1 de amostra úmida. Cálculos dos percentuais de adequação da ingestão diária recomendada de cada genótipo para grupos de risco (crianças entre 4 e 8 anos e gestantes entre 19 e 30 anos), com base no consumo de uma porção média de 200 g diários, foram realizados. As batatas-doces apresentaram grande variação na quantidade de minerais entre os genótipos e o potássio foi o mais abundante em todos estes, com destaque para os genótipos ILS 44, ILS 56 e ILS 71. Os genótipos de coloração roxa se sobressaíram na quantidade de potássio e os de coloração creme, na quantidade de fósforo. O consumo de uma porção média de 200 g de qualquer uma das batatas-doces forneceria 28% da necessidade de magnésio a crianças de 4 a 8 anos, e em torno de 20% das necessidades diárias de magnésio e 10% de potássio para gestantes.

Incorporating orange-fleshed sweet potato into the food system as a strategy for improved nutrition: The context of South Africa

Orange-fleshed sweet potato (OFSP) is considered the single most successful example of biofortification of a staple crop, and presents a feasible option to address vitamin A deficiency. Though initially promoted as part of a crop-based approach focusing on production and consumption at household level, it evolved into small-scale commercial production, predominantly in Sub-Saharan Africa. This paper reviews OFSP initiatives in relation to the South African food environment and food supply systems, also identifying opportunities for scaling out OFSP in a situation where sweet potato is not eaten as a staple. Current per capita consumption of sweet potato is low; the focus is thus on increasing consumption of OFSP, rather than replacing cream-fleshed varieties. For the major OFSP variety, Bophelo, 66g consumption can be sufficient to meet the recommended daily allowance for 1-3year old children (300μRE vitamin A). Despite a national Vitamin A supplementation programme and fortified staple foods in South Africa, 43.6% of children under 5years of age were reported to be vitamin A deficient in 2012, indicating a stronger need to promote the consumption of Vitamin A-rich foods, such as OFSP. To increase availability of and access to OFSP, all aspects of the food supply system need to be considered, including agricultural production, trade, food transformation and food retail and provisioning. Currently, small-scale commercial OFSP producers in South Africa prefer to deliver their produce to local informal markets. To enter the formal market, small-scale producers often have difficulties to meet the high standards of the retailers' centralised procurement system in terms of food quality, quantity and safety. Large retailers may have the power to increase the demand of OFSP, not just by improving availability but also by developing marketing strategies to raise awareness of the health benefits of OFSP. However, currently the largest scope for scaling out is through a number of public sector programmes such as the National School Nutrition Programme, Community Nutrition and Development Centres, Small-holder Farmer programmes and Agriparks. Though the major approach is focused on unprocessed, boiled OFSP, there are unexploited opportunities for processing of OFSP. However, the nutritional quality of products should be a main consideration within the context of the co-existence of undernutrition, overnutrition and micronutrient deficiencies in the country.

Antioxidants: Characterization, natural sources, extraction and analysis

Recently many review papers regarding antioxidants from different sources and different extraction and quantification procedures have been published. However none of them has all the information regarding antioxidants (chemistry, sources, extraction and quantification). This article tries to take a different perspective on antioxidants for the new researcher involved in this field. Antioxidants from fruit, vegetables and beverages play an important role in human health, for example preventing cancer and cardiovascular diseases, and lowering the incidence of different diseases. In this paper the main classes of antioxidants are presented: vitamins, carotenoids and polyphenols. Recently, many analytical methodologies involving diverse instrumental techniques have been developed for the extraction, separation, identification and quantification of these compounds. Antioxidants have been quantified by different researchers using one or more of these methods: in vivo, in vitro, electrochemical, chemiluminescent, electron spin resonance, chromatography, capillary electrophoresis, nuclear magnetic resonance, near infrared spectroscopy and mass spectrometry methods.

Nutritional and physical properties of organic Beauregard sweet potato [Ipomoea batatas (L.)] as influenced by broiler litter application rate

Organic farming has been on an upward trend in recent years. However, the manures used like broiler litter have variable nutrient content, making it important to establish optimal application rate, for maximum crop yield and quality. Additionally, some states like Alabama restricts the amount of broiler litter to control excessive nutrients accumulation which can lead to surface and ground water contamination. The current study evaluated the effect of broiler litter at rates 0, 0.5, 1, 2, and 3 t ha⁻¹ (treatments T₀, T_0.5, T₁, T₂, and T₃), on the nutritional and physical properties of Beauregard sweet potato. Analyses were performed to determine moisture, ash, fiber, vitamin C, and β-carotene contents using oven, muffler furnace, dye, and spectrophotometric methods; texture; and color using compressive strength and L, a, b system, respectively. Ash content of the samples ranged from 0.9% to 1.4% with a very strong positive linear correlation (r = 0.9) to the broiler litter rate. However, vitamin C had a quadratic relationship with the broiler litter rate with a peaking at T_0.5 (15.5 mg/100 g). The yellow color (b-value) also had a strong linear relationship with the broiler litter rate (r = 0.86). However, the other measures showed moderate, weak, or negligible correlations to the broiler litter level. T_0.5 had the highest β-carotene (262.0 μg/g), dry matter contents and had the most firm (0.040 kN) sweet potatoes with the deepest orange color (L = 60.7). Based on the study's findings, 0.5 t ha⁻¹ appeared to be appropriate level of broiler litter, which is consistent with Alabama's law and is also advantageous in terms of low cost of farming practices and water pollution reduction.

The use of sensory attributes, sugar content, instrumental data and consumer acceptability in selection of sweet potato varieties

BACKGROUND

As eating quality is important for adoption of new varieties, nine orange-fleshed and three cream-fleshed sweet potato varieties were assessed for sensory characteristics, dry mass and free sugar content, instrumental texture and colour and consumer acceptability (n =  216) in a peri-urban South African setting.

RESULTS

Cream-fleshed varieties were higher in yellow-green colour and sweet potato-like flavour and lower in graininess. Orange-fleshed varieties were higher in pumpkin-like flavour, orange colour, discolouration and sucrose content. Partial least squares regression analysis showed that the most accepted varieties (Impilo, Excel, Resisto, 2001_5_2, Serolane, W-119 and Monate) were associated with sweet flavour, dry mass and maltose content, while the least accepted varieties (Beauregard, Khano and 1999_1_7) were associated with wateriness. Pearson correlation analysis highlighted correlations of sensory attributes yellow and orange with instrumental colour measurements (colour a* and colour b*), instrumental firmness with sensory firmness, dry mass with sensory wateriness, and maltose content with sensory sweet and sweet potato-like flavour. The varieties were clustered into three groups. Consumer acceptability for eating quality correlated with maltose content, dry mass and sweet flavour.

CONCLUSION

Chemical and instrumental measurements were identified to evaluate key attributes and will be useful in the intermediate phases of sweet potato varietal development.