Production of buns, the bakery-based snack food, with reduced refined wheat flour content: Recent developments

Buns are very soft puffed bakery snack items, popular in many countries, especially low- and middle-income nations. Buns are either eaten directly or used in the preparation of culinary items. Buns are mainly prepared using refined wheat flour rich in gluten protein and devoid of husk. Consuming gluten-containing foods is leading to several health complications among consumers worldwide. Hence, several researchers have tried to reduce the gluten content in the dough by incorporating cereals flours, protein-rich sources like soy, cheese whey, etc., hydrocolloids, millets, pomace, and seed flour of vegetables and fruits, etc. These additives not only reduce gluten content in the buns to a certain extent but also enhance the fibre content and nutritional profile of the buns. This mini-review summarizes the recent developments in the production of buns using these additives to improve their nutritional quality.

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.

Effect of Orange-Fleshed Sweet Potato Purée and Wheat Flour Blends on β-Carotene, Selected Physicochemical and Microbiological Properties of Bread

Partial substitution of wheat flour with orange-fleshed sweet potato (OFSP) purée in bread can increase vitamin A intake among consumers. The study investigated the influence of wheat flour substitution with 20–50% of OFSP purée on proximate composition, color, β-carotene, water activity, and microbial keeping quality. The moisture content, crude protein, crude fat, total ash, crude fiber, and carbohydrate in bread ranged from 28.6–32.7%, 9.9–10.6%, 5.0–5.5%, 1.9–3.2%, 1.4–1.8%, and 79.1–80.9%, respectively. β-carotene, total ash, and crude fiber contents in bread, and Hunter color values a*, b*, chroma, and ∆E significantly increased with the addition of OFSP purée. Total viable counts (TVC), yeast, and molds in bread ranged from 2.82–3.64 log10 cfu/g and 1.48–2.16 log10 cfu/g, respectively, on the last day of storage. Water activity, TVC, and fungal counts were low in sweet potato composite bread as compared to white bread. Total β-carotene in OFSP bread ranged from 1.9–5.4 mg/100 g (on dry weight). One hundred grams of bread portion enriched with 40% and 50% OFSP purée provides more than 50% of vitamin A dietary requirements to children aged 4–8 years. Incorporation of up to 50% OFSP purée in wheat flour produces a relatively shelf-stable, nutritious, and health-promoting functional bread.

Marketing Healthy Food in an African City: Consumer Motivations for Adopting Orange-Fleshed Sweet Potato in Maputo, Mozambique

Since the late 1990s, the International Potato Center has promoted orange-fleshed sweet potato (OFSP) cultivars in Mozambique as a healthy food, emphasizing its capacity to reduce the prevalence of vitamin A deficiency among mothers and young children. This article seeks to reveal why consumers in Maputo, the capital city of Mozambique, adopt or reject OFSP looking at the role of food systems and consumer characteristics in access and acceptance of healthy food and at the positioning OFSP on the market in terms of lifestyle and need satisfaction.The results of 255 street interviews confirm that OFSP is widely known. Information reaches people mainly via informal channels (relatives and retailers). Nonadoption is the result of the positioning of OFSP as food for young children and sick people. The OFSP appeals most to the hedonistic and conservative lifestyle segments. Adoption is associated with the perception of OFSP as a source of vitamins that builds up muscles and improves physical appearance and self-fulfillment. While women are typically responsible for domestic tasks, male adopters emphasize the role of OFSP in family health and well-being more than female adopters. This first attempt to understand the marketing of healthy food in Mozambique exposes many similarities between the urban consumers in Maputo and those in developed countries. The results indicate that future marketing should exploit informal channels such as vendors and emphasize its nutritious value for all consumers instead of focusing on mothers and young children.

Quality and psychosocial factors influencing purchase of orange-fleshed sweetpotato bread

This 2018 study, conducted in six Tusky's supermarkets in Nairobi, Kenya, combined the Just-About-Right, Penalty and Mean-End-Chain analyses to examine the quality and psychosocial factors influencing the purchase of a novel bread made from orange-fleshed sweet potato (OFSP), a biofortified crop, focusing on sixty-one male and eighty female urban OFSP bread buyers recruited at point of purchase. It finds that sensory and psychosocial factors drive purchasing decisions and that some of the bread's sensory characteristics are misaligned with consumers' expectations. It also finds that women and men's evaluations of the bread's characteristics are different, as are their motivations for purchase. However, good sensory attributes and the knowledge of the bread's nutritional value were key drivers. Some misaligned characteristics reveal levers for the reformulation of the bread and present opportunities for segmenting the market. Several other implications of the findings for policy and future improvement of the bread are discussed.

Understanding innovation: The development and scaling of orange-fleshed sweetpotato in major African food systems

The development and scaling of orange-fleshed sweetpotato (OFSP) during the past 25 years is a case study of a disruptive innovation to address a pressing need - the high levels of vitamin A deficiency among children under five years of age in sub-Saharan Africa. When the innovation was introduced consumers strongly preferred white or yellow-fleshed sweetpotato, so it was necessary to create a demand to respond to that need. This was at odds with the breeding strategy of responding to consumers' demands. Additional elements of the innovation package include seed systems and nutrition education to create the awareness amongst consumers of the significant health benefits of OFSP. Complementary innovation is required in promotion and advocacy to ensure a supportive institutional environment. Four dimensions-- technical, organizational, leadership, and institutional environment-- are explored across five distinct phases of the innovation process, from the emergence of the innovative idea (1991-1996) through scaling phase in 15 countries under a major institutional innovation (2015-mid-2019), the Sweetpotato for Profit and Health Initiative (SPHI). Systematically gathering evidence of nutritional impact and ability to scale cost-effectively was requisite for obtaining support for further development and diffusion of the crop. Positive findings from a major study coincided with a major change in the institutional environment which placed agriculture and nutrition at the forefront of the development agenda, resulting in an inflection point in both research and diffusion investment. The role of committed leadership during all phases was critical for success, but particularly during the first decade of limited support in a challenging institutional environment. The most critical technical achievement underpinning scaling was moving from 2 to 13 African countries having local breeding programs. Evidence is presented that adapted, well performing varieties which consumers prefer is the foundation for successful scaling to occur. Building a cadre of within country and regional advocates was critical for getting sustained commitment and local buy-in to the concept of biofortification by regional bodies and governments, which in turn built within country ownership and the willingness of donors to invest. The SPHI united diverse organizations under a common vision with a simple metric--- the number of households reached with improved varieties of sweetpotato. Since 2009, 6.2 million households were reached by July 2019 in 15 SSA countries. Much more remains to be done. Advocacy efforts led to the integration of nutritious foods into many national and regional policies, setting the stage for further investment.

Stability and Quality of Anthocyanin in Purple Sweet Potato Extracts

Because of the high nutritional value of anthocyanin in purple sweet potatoes (TN57), the stability and quality of anthocyanin in purple sweet potatoes during and after the processing were investigated in this study. First of all, the extraction methods with different parameters, such as temperature, time, solid-liquid ratio, pH value, and solvent were employed to get better extraction efficiencies. After that, DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2′-azino-bis (3-ethylbenz thiazoline-6-sulphonic acid) were used to evaluate the anti-oxidation ability of the extracts. Lastly, the thermal degradation kinetics and photodegradation were used to obtain important degradation factors including the content of anthocyanin residue, degradation index (DI), color parameters, reaction rate (k), and chromatic aberration (ΔE). We found that the extraction condition as using 60% ethanol with 1% citric acid under 80 °C for 40 min was optimal for purple sweet potatoes, which obtained antioxidant capacity as 333 μM TE DPPH, 376 μM TE ABTS⁺, and 593.6 μM TE ferric ion reducing antioxidant power (FRAP). The results indicate that the most important parameter for the stability of anthocyanin in the purple sweet potato extract (PSPAE) was the pH value rather than temperature. In addition, there was no significant difference in chromatic aberration between the light and dark storage conditions under 37 °C. Thus, PSPAE has the potential to be developed as health foods and drinks rich in anthocyanin.

Consumer Perceptions and Acceptability of Traditional Dishes Prepared with Provitamin A-Biofortified Maize and Sweet Potato

Vitamin A deficiency (VAD) is prevalent in South Africa, particularly among predominantly poor rural communities. Provitamin A (PVA)-biofortified crops could be used to address VAD; however, there are challenges of poor consumer acceptability. This study investigated the effect of replacing white maize and cream-fleshed sweet potato (CFSP) with PVA-biofortified maize and orange-fleshed sweet potato (OFSP), respectively, on consumer acceptability and perceptions of traditional dishes of rural communities in South Africa. Consumer acceptability of PVA-biofortified phutu (a crumbly maize porridge) served with either curried cabbage, chicken or bambara groundnut, separately, and boiled OFSP was evaluated by black South African adults (n = 120) using a five-point facial hedonic scale. Focus group discussions (FGDs) were conducted with 56 subjects recruited from the consumer panel to assess consumer perceptions of the food samples. The majority of the participants rated the composite dishes containing PVA-biofortified phutu as "4 = good" and the acceptability of the composite dishes varied significantly (p < 0.05). Compared to other age groups, the 50-59-year age group showed higher preference for white phutu and chicken curry, whereas the 30-39-year age group showed higher preference for PVA-biofortified phutu and chicken curry. The acceptability of OFSP and CFSP was similar. The study participants showed positive perceptions of the OFSP, as well as PVA-biofortified phutu if served with either curried chicken or cabbage. The findings suggest that PVA-biofortified maize and OFSP can replace white maize and CFSP, respectively, in selected traditional dishes of the rural communities studied to alleviate VAD.

Improving the Dietary Vitamin A Content of Rural Communities in South Africa by Replacing Non-Biofortified white Maize and Sweet Potato with Biofortified Maize and Sweet Potato in Traditional Dishes

Biofortification of staple crops has a potential for addressing micronutrient deficiencies, such as vitamin A deficiency (VAD), which are prevalent in South Africa. The poor acceptability of provitamin A (PVA)-biofortified foods could be improved by combining them with other food items to produce modified traditional dishes. The nutritional composition of the dishes could also be improved by the modification. The study aimed to investigate the effect of replacing white maize and cream-fleshed sweet potato (CFSP)] with PVA-biofortified maize and orange-fleshed sweet potato (OFSP) on the nutritional composition of South African traditional dishes. The protein, fibre, total mineral (ash), lysine, and iron concentrations of the PVA maize phutu (traditional porridge) composite dishes (control), were not significantly different (P > 0.05) from those of white maize phutu composite dishes. However, the PVA concentration of PVA maize phutu composite dishes was higher than that of the white phutu composite dishes (P > 0.05). The OFSP had a significantly lower protein concentration, but a significantly higher (P > 0.05) fibre, ash, lysine, isoleucine, leucine, and PVA concentration, relative to the CFSP. The findings indicate that composite dishes in which white maize is replaced with PVA-biofortified maize, and switching over from CFSP to OFSP, would contribute to combating VAD in South Africa, and in other developing counties.

Amaranth Leaves and Skimmed Milk Powders Improve the Nutritional, Functional, Physico-Chemical and Sensory Properties of Orange Fleshed Sweet Potato Flour

Vitamin A deficiency (VAD) and under nutrition are major public health concerns in developing countries. Diets with high vitamin A and animal protein can help reduce the problem of VAD and under nutrition respectively. In this study, composite flours were developed from orange fleshed sweet potato (OFSP), amaranth leaves and skimmed milk powders; 78:2:20, 72.5:2.5:25, 65:5:30 and 55:10:35. The physico-chemical characteristics of the composite flours were determined using standard methods while sensory acceptability of porridges was rated on a nine-point hedonic scale using a trained panel. Results indicated a significant (p < 0.05) increase in protein (12.1 to 19.9%), iron (4.8 to 97.4 mg/100 g) and calcium (45.5 to 670.2 mg/100 g) contents of the OFSP-based composite flours. The vitamin A content of composite flours contributed from 32% to 442% of the recommended dietary allowance of children aged 6–59 months. The composite flours showed a significant (p < 0.05) decrease in solubility, swelling power and scores of porridge attributes with increase in substitution levels of skimmed milk and amaranth leaf powder. The study findings indicate that the OFSP-based composite flours have the potential to make a significant contribution to the improvement in the nutrition status of children aged 6–59 months in developing countries.

Production, Utilization and Nutritional benefits of Orange Fleshed Sweetpotato (OFSP) Puree Bread: A Review

Bread though an exotic food product in sub-Saharan Africa, has been an important cereal product consumed by most individuals among the vast Sub-Saharan African population. Bread formulations in both the local and industrial production have evolved. The latest and emerging technology in bread formulation involve the incorporation of orange-fleshed sweetpotato (OFSP) puree. OFSP puree-based bread is commercially available across sub-Saharan Africa (SSA) and is being promoted due to the potential nutritional benefits that it possesses. Together with OFSP flour based bread, OFSP puree based bread serves as a good food vehicle for β-carotene; this serves to alleviate vitamin A deficiency (VAD) especially among the vulnerable population in SSA. The production of OFSP puree based bread has so far been relying on fresh OFSP puree or cold-chain stored OFSP puree. However, this has presented economic challenges and problems to the sustainability and expansion in OFSP puree bread production. Cold chain stored OFSP puree is capital intensive and has inconsistent supply. With the development of shelf-storable preservative treated OFSP puree, most of these challenges will be overcome without undoing the currently harnessed benefits. The use of OFSP puree in bread baking can then be expanded easily at minimal production costs and maximum retention of nutritional quality. Therefore, the use of the shelf-storable OFSP puree in bread baking needs to be evaluated further to present a substantiated case for its use. The current review has been developed with focus on the scientific advances in the production of OFSP puree based bread from both historical and a forecast perspective. The scientific progress and breakthroughs in the use of OFSP puree in bread are critically reviewed.

The physiochemical properties and shelf-life of orange-fleshed sweet potato puree composite bread

Value addition of orange-fleshed sweet potato (OFSP) increases diversified utilization of this crop, which is rich in provitamin A carotenoids. OFSP bread, in which 30%-45% of wheat flour is replaced with OFSP puree, has been successfully commercialized in Kenya. However, the effect of this substitution on the bread's physiochemical properties and its shelf-life are currently unknown. This study was designed to determine the physiochemical properties and shelf-life of OFSP puree-wheat flour composite bread (30% puree), compared to standard, 100% wheat flour, bread. Freshly baked bread samples were stored at 7, 20, 25, and 30°C, and monitored for moisture content, water activity, color, texture, volume, carotenoids, and microbial load. The moisture content, β-carotene content, and color of bread significantly decreased with increase in storage temperature and time (p < 0.05). Bread made with OFSP puree had a longer shelf-life, showing spoilage on day six compared with the white bread, which spoiled on the fourth day. This is attributed to the significantly higher water activity in white bread than in the OFSP bread. The substitution of wheat with OFSP puree resulted in reduced extensibility of gluten, thus, specific volume of white bread was significantly (p < 0.05) higher than that in OFSP puree bread. Refrigeration increased crumb firmness, chewiness and cohesiveness in both types of bread. In conclusion, OFSP puree increases the water binding capacity of the bread, which reduces water activity and increases its shelf-life.

Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya

Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly (P < 0.05) reduced microbial load in OFSP cooked roots but the counts significantly (P < 0.05) increased in the puree due to postprocessing contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, and E. coli and S. aureus counts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log₁₀ cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree.

Orange-fleshed sweet potato (Ipomoea batatas) composite bread as a significant source of dietary vitamin A

Refining food recipes with orange-fleshed sweet potato (OFSP) has the potential to improve dietary intake of vitamin A. The objectives of this study were to utilize OFSP in the development of two composite bread types and to assess their contribution to dietary intake of vitamin A using the dietary reference intake of lactating mothers. Two composite OFSP-wheat flour bread recipes-vita butter bread and vita tea bread-were developed by incorporating 46% OFSP puree in existing 100% wheat flour bread recipes consumed by Ghanaians. A paired-preference test was used to profile the appearance, aroma, sweetness, and overall degree of liking of the vita butter bread and vita tea bread and their respective 100% wheat flour bread types. Weighed bread intake by lactating mothers (n = 50) was used to estimate the contribution to dietary vitamin A based on the trans β-carotene content. The developed vita butter bread and vita tea bread were most preferred by at least 77% (p < .05) of consumers (n = 310) for all the attributes considered. The average daily intake by the lactating mothers for vita butter bread was 247 g, and for vita tea bread was 196 g. The trans β-carotene content of vita butter bread and vita tea bread were found to be 1.333 mg/100 g and 0.985 mg/100 g, respectively. The estimated trans-β-carotene intake was 3,293 μg/day (vita butter) and 1,931 μg/day (vita tea) based on the weighed bread intake, respectively, meeting 21% and 12% of the daily requirement (1,300 μg RAE/day) for lactating mothers, the life stage group with the highest vitamin A requirement. OFSP therefore could composite wheat flour to bake butter and tea bread, and will contribute to significant amount of dietary intake of vitamin A.

Acceptance and adoption of biofortified crops in low- and middle-income countries: a systematic review

CONTEXT

Biofortification of staple crops is a promising strategy for increasing the nutrient density of diets in order to improve human health. The willingness of consumers and producers to accept new crop varieties will determine whether biofortification can be successfully implemented. This review assessed sensory acceptance and adoption of biofortified crops and the determining factors for acceptance and adoption among consumers and producers in low- and middle-income countries. PubMed, Scopus, and Web of Science were searched for published reports. Unpublished studies were identified using an internet search. From a total of 1669 records found, 72 primary human research studies published in English or Spanish met the criteria for inclusion. : Data were extracted from each identified study using a standardized form. Sensory acceptability (n = 40) was the most common topic of the studies, followed by determinants of acceptance (n = 25) and adoption (n = 21). Of crops included in the studies, sweet potato and maize were the most studied, whereas rice and pearl-millet were the least investigated. Overall, sensory acceptance was good, and availability and information on health benefits of the crops were the most important determinants of acceptance and adoption. : Changes to the sensory qualities of a crop, including changes in color, did not act as an obstacle to acceptance of biofortified crops. Future studies should look at acceptance of biofortified crops after they have been disseminated and introduced on a wide-scale.

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.

Orange-Fleshed Sweet Potato: Successes and Remaining Challenges of the Introduction of a Nutritionally Superior Staple Crop in Mozambique

BACKGROUND

Chronic vitamin A deficiency affects both women and children in Mozambique and populations worldwide and cannot be addressed through supplementation alone. Food-based approaches encouraging the consumption of vitamin A-rich foods, such as the orange-fleshed sweet potato (OFSP), have the potential to positively affect vitamin A status. A range of OFSP varieties have been introduced in sub-Saharan Africa in rural and urban environments and emergency and nonemergency contexts.

OBJECTIVE

To highlight the successes to date and remaining challenges of the introduction of OFSP to increase vitamin A consumption in Mozambique, collating a time line of key events.

METHODS

A systematic review of literature using The Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

The systematic search resulted in 20 studies that met inclusion criteria. Data extracted include author and year, study location and duration, project partners, project title, sample size and characteristics, objectives, methods and measures, and outcomes.

CONCLUSIONS

Orange-fleshed sweet potatoes are widely accepted by Mozambican farmers and consumers, and various studies show a positive impact on vitamin A status due to the introduction of this nutritionally superior staple crop. Remaining challenges include vine preservation, pest and disease management, market development, and storage and processing.

Food Fortification for Addressing Iron Deficiency in Filipino Children: Benefits and Cost-Effectiveness

Iron deficiency is one of the most widespread nutritional disorders in both developing and industrialized countries, making it a global public health concern. Anemia, mainly due to iron deficiency, affects one third of the world's population and is concentrated in women and children below 5 years of age. Iron deficiency anemia has a profound impact on human health and productivity, and the effects of iron deficiency are especially pronounced in the first 1,000 days of life. This critical window of time sets the stage for an individual's future physiological and cognitive health, underscoring the importance of addressing iron deficiency in infants and young children. This review focuses on the use of fortified foods as a cost-effective tool for addressing iron deficiency in infants and young children in the Philippines.

The effects of household food production strategies on the health and nutrition outcomes of women and young children: a systematic review

The objective of this review is to systematically examine and summarise the effects of agricultural interventions to increase household food production on the nutrition and health outcomes of women and young children and provide recommendations for future research and programming. Data from all studies meeting inclusion/exclusion criteria were abstracted into a standardised form. The quality of the evidence was assessed and graded using a modified version of the Child Health Epidemiology Reference Group adaptation of the Grading of Recommendations, Assessment, Development and Evaluation technique. Thirty-six articles, representing 27 unique projects were identified. Of these 32 and 17 reported on the health and nutrition outcomes of children and women, respectively. Although studies were too heterogeneous to conduct meta-analysis, agricultural strategies consistently reported significantly improved diet patterns and vitamin A intakes for both women and children. Although some individual studies reported significant reductions in child malnutrition, summary estimates for effects on stunting [relative risk (RR) 0.93 [95% confidence interval (CI) 0.84, 1.04]], underweight (RR 0.80 [95% CI 0.60, 1.07]) and wasting (RR 0.91 [95% CI 0.60, 1.38]) were not significant. Findings for an effect on vitamin A status, anaemia and morbidity were inconsistent. Overall the evidence base for the potential of agricultural strategies to improve the nutrition and health of women and young children is largely grounded in a limited number of highly heterogeneous, quasi-experimental studies, most of which have significant methodological limitations. While household food production strategies hold promise for improving the nutrition of women and children, the evidence base would be strengthened by additional research that is methodologically robust and adequately powered for biological and dietary indicators of nutrition.

Efficient embryogenic suspension culturing and rapid transformation of a range of elite genotypes of sweet potato (Ipomoea batatas [L.] Lam.)

Efficient Agrobacterium tumefaciens-mediated transformation was developed using embryogenic suspension cell cultures of elite sweet potato (Ipomoea batatas [L.] Lam.) cultivars, including Ayamurasaki, Sushu2, Sushu9, Sushu11, Wanshu1, Xushu18 and Xushu22. Embryogenic suspension cultures were established in LCP medium using embryogenic calli induced from apical or axillary buds on an induction medium containing 2 mg l(-1) 2,4-D. Suspension cultures were co-cultivated with A. tumefaciens strain LBA4404 harboring the binary plasmid pCAMBIA1301 with the hpt gene as a selectable marker and an intron-interrupted uidA gene as a visible marker. Several key steps of the sweet potato transformation system have been investigated and optimized, including the appropriate antibiotics and their concentrations for suppressing Agrobacterium growth and the optimal doses of hygromycin for transformant selection. A total of 485 putative transgenic plant lines were produced from the transformed calli via somatic embryogenesis and germination to plants under 10 mg l(-1) hygromycin and 200 mg l(-1) cefotaxime. PCR, GUS and Southern blot analyses of the regenerated plants showed that 92.35% of them were transgenic. The number of T-DNA insertions varied from one to three in most transgenic plant lines. Plants showed 100% survival when 308 transgenics were transferred to soil in the greenhouse and then to the field. Most of them were morphologically normal, with the production of storage roots after 3 months of cultivation in the greenhouse or fields. The development of such a robust transformation method suitable to a range of sweet potato genotypes not only provides a routine tool for genetic improvement via transgenesis but also allows us to conduct a functional verification of endogenous genes in sweet potato.

A large-scale intervention to introduce orange sweet potato in rural Mozambique increases vitamin A intakes among children and women

β-Carotene-rich orange sweet potato (OSP) has been shown to improve vitamin A status of infants and young children in controlled efficacy trials and in a small-scale effectiveness study with intensive exposure to project inputs. However, the potential of this important food crop to reduce the risk of vitamin A deficiency in deficient populations will depend on the ability to distribute OSP vines and promote its household production and consumption on a large scale. In rural Mozambique, we conducted a randomised, controlled effectiveness study of a large-scale intervention to promote household-level OSP production and consumption using integrated agricultural, demand creation/behaviour change and marketing components. The following two intervention models were compared: a low-intensity (1 year) and a high-intensity (nearly 3 years) training model. The primary nutrition outcomes were OSP and vitamin A intakes by children 6-35 months and 3-5·5 years of age, and women. The intervention resulted in significant net increases in OSP intakes (model 1: 46, 48 and 97 g/d) and vitamin A intakes (model 1: 263, 254 and 492 μg retinol activity equivalents/d) among the younger children, older children and women, respectively. OSP accounted for 47-60 % of all sweet potato consumed and, among reference children, provided 80 % of total vitamin A intakes. A similar magnitude of impact was observed for both models, suggesting that group-level trainings in nutrition and agriculture could be limited to the first project year without compromising impact. Introduction of OSP to rural, sweet potato-producing communities in Mozambique is an effective way to improve vitamin A intakes.

In vitro bioaccessibility of beta-carotene in orange fleshed sweet potato (Ipomoea batatas, Lam.)

Substitution of white with orange fleshed varieties of sweet potatoes (OFSP) was recently shown to alleviate vitamin A deficiency in children in Africa. However, the relationship between beta-carotene (BC) content of different cultivars of OFSP and its bioavailability is unknown. Here, we used the three phase (oral, gastric and small intestinal) in vitro digestion procedure to examine the bioaccessibility of BC from eight cultivars of boiled OFSP. All-trans BC (all-E-BC) was the only isomer of BC detected in raw roots for cultivars of OFSP with amounts ranging from 112 to 281 microg/g. Boiling OFSP decreased all-E-BC content by 11% with conversion to 13-cis BC (13-Z-BC). The efficiency of BC micellarization during simulated digestion of boiled OFSP was only 0.6-3%. Addition of soybean oil (2% vol/wt) to boiled OFSP prior to in vitro digestion more than doubled partitioning of all-E-BC in the micelle fraction for all cultivars. The relatively poor bioaccessibility of all-E-BC was not a limitation of the in vitro model as micellarization was proportional to amount of OFSP digested from 0.5 to 3.0 g and minimally altered by increasing bile salt content during small intestinal digestion. Moreover, micellarization of all-E-BC from boiled fresh OFSP and commercially processed OFSP was significantly less than from carrots processed identically. These results indicate the need for further efforts to elucidate the basis for relatively poor bioaccessibility of BC from OFSP.