Household food insecurity in Timor-Leste

Timor-Leste is among the world’s youngest and poorest countries. It suffers from seasonal food insecurity and has the third-highest stunting rate globally. Previously inadequately documented, this paper summarises recent advances in understanding household food security in Timor-Leste and the multifaceted approaches being used to overcome it. Information comes from the extensive annual surveys of the Seeds of Life (SoL) program in Timor-Leste. The hungry season prior to maize and rice harvests is the key issue in household food security in Timor-Leste. Farm households cope with the problem through crop diversification with tubers playing a lead role as grain stocks dwindle. Foraging for wild food resources, selling animals and other assets, and social networks are other coping strategies. To address seasonal food insecurity, the government has focused on rice importation and the improvement of agricultural productivity within a multi-dimensional program. Information on storage by households of the key staple, maize, indicates an improving trend in food security at the household level from 2006/2007 to 2010/2011 through a significant reduction in the percentage of ‘at risk’ households—those who grow insufficient maize for storage during the year. The current emphasis on the widespread dissemination of the new high-yielding SoL cultivars has the potential to augment these improving trends. Nevertheless this picture remains vulnerable to weather shocks—such as drought—which are anticipated to increase with climate change and it is important to build further resilience into the agricultural systems of Timor-Leste.     

Retention of Provitamin A Carotenoids in Staple Crops Targeted for Biofortification in Africa: Cassava,Maize and Sweet Potato

HarvestPlus, part of the Consultative Group on Internation Agriculture research (CGIAR) Program on Agriculture for Nutrition and Health (A4NH) uses conventional plant breeding techniques to develop staple food crops that are rich in micronutrients, a food-based approach to reduce micronutrient malnutrition known as biofortification. The nutritional breeding targets are established based on the food intake of target populations, nutrient losses during storage and processing and bioavailability. This review collates the evidence on the retention of provitamin A carotenoid (pVAC) after processing, cooking, and storing of the staple crops targeted for pVAC biofortification: cassava, maize, and sweet potato. Sun drying was more detrimental to the pVAC levels (27–56% retention) in cassava than shade (59%) or oven (55–91%) drying, while the pVAC retention levels (66–96%) in sweet potato were not significantly different among the various drying methods. Overall, boiling and steaming had higher pVAC retention (80–98%) compared to baking (30–70%) and frying (18–54%). Gari, the most frequently consumed form of cassava in West Africa had the lowest pVAC retention (10–30%). The pVAC retention of maize grain and cassava and sweet potato flour reached levels as low as 20% after 1–4 months of storage and was highly dependent on genotype. Therefore, we recommend that an evaluation of the pVAC degradation rate among different genotypes be performed before a high pVAC crop is promoted.     

粮油中可开发的功能性成分

近年来,功能性食品成为世界食品工业新的增长点,为功能性食品配套的作为添加剂和配料的功能性成分也成为国内外竞相研究和开发的热点。水稻、小麦、玉米、大豆、花生、芝麻及红薯等为我国主要的粮油作物,这些粮油作物含有丰富的对人体健康有益的功能活性成分。本文对这些粮油作物中可供开发的功能性成分进行了简要综述,为粮油作物中功能性添加剂及配料的开发提供参考,进而促进粮油资源价值的充分发掘。     

Impact of improved maize adoption on household food security of maize producing smallholder farmers in Ethiopia

In recent years, maize has gained prominence as an important staple crop in Ethiopia second only to teff in terms of acreage. Most of this is grown by semi-subsistence farm households whose livelihoods are tied to crop production and some livestock keeping. Therefore, an important policy question concerns the impact that the reported maize revolution has had on household food security. This paper answers that question by examining the empirical regularities that explain the adoption of improved maize varieties (IMVs) and how this has impacted household food security in a sample of 2327 maize producing households in 39 districts of Ethiopia. An endogenous switching regression model supported by the dose-response continuous treatment effect method was used to empirically assess the impact of IMV adoption on per capita food consumption expenditure and perceived household food security status. Results show that IMV adoption has a robust and positive impact on per capita food consumption and also significantly increases the probability of a smallholder being in food surplus. The advances in the adoption of improved maize has thus contributed significantly to the food security of maize producing smallholders, confirming the role of crop improvement in contributing to food security of agrarian households.     

鄂西北稀土矿区粮食与蔬菜中重金属污染风险评价

目的 调查鄂西北稀土矿区粮食作物与蔬菜中重金属污染情况及其健康风险。方法 对当地居民日常食用、本地种植的6种粮食及20种蔬菜进行采样,用微波消解ICP—MS对样本中具有代表性的重金属 Cr、Pb、Hg、Cd及类金属As的含量进行测定,选用靶标危害系数法、内梅罗污染指数法、单因子污染指数法综合评价了不同作物的重金属污染风险。结果 研究区粮食中大米、小麦、花生以及蔬菜中菠菜、苋菜、红薯叶等叶菜类蔬菜及茄子、小葱均受到了不同程度的重金属污染。其中粮食作物的重金属污染多为单一铬污染,蔬菜的污染类型多为复合型重金属污染。结论 健康风险评价表明食用该地区种植的大米、苋菜、红薯叶对健康产生影响的可能性极大;食用该地区种植的小麦、油麦菜、菠菜产生重金属危害的可能性较大;过量食用当地种植的花生、茄子、小葱、萝卜叶,也存在一定的风险。     

Improved production systems for traditional food crops: the case of finger millet in western Kenya

Increasing agricultural productivity through the dissemination of improved cropping practices remains one of the biggest challenges of this century. A considerable amount of literature is dedicated to the adoption of improved cropping practices among smallholder farmers in developing countries. While most studies focus on cash crops or main staple crops, traditional food grains like finger millet have received little attention in the past decades. Traditional food grains have however an important potential to improve food security, reduce micronutrient deficiencies, and enhance smallholder adaptation to climate change. The present study aims to assess the factors that influence adoption decisions among finger millet farmers in western Kenya. Based on cross-sectional household data from 270 farmers, we estimated a multivariate probit model to compare the adoption decisions in finger millet and maize production. While improved practices such as the use of a modern variety or chemical fertilizer are relatively well adopted in maize production, they are less common in finger millet production. Social networks as well as access to extension services play crucial roles in the adoption of improved finger millet practices, while the same variables are of minor importance for the adoption of improved maize practices. A Cobb-Douglas production function shows a positive effect of modern varieties and chemical fertilizer on finger millet yields.     

Potential impacts of bioprocessing of sweet potato: Review

Sweet potato (Ipomoea batatas L.) is among the major food crops in the world and is cultivated in all tropical and subtropical regions particularly in Asia, Africa, and the Pacific. Asia and Africa regions account for 95% of the world's production. Among the root and tuber crops grown in the world, sweet potato ranks second after cassava. In previous decades, sweet potato represented food and feed security, now it offers income generation possibilities, through bioprocessing products. Bioprocessing of sweet potato offers novel opportunities to commercialize this crop by developing a number of functional foods and beverages such as sour starch, lacto-pickle, lacto-juice, soy sauce, acidophilus milk, sweet potato curd and yogurt, and alcoholic drinks through either solid state or submerged fermentation. Sweet potato tops, especially leaves are preserved as hay or silage. Sweet potato flour and bagassae are used as substrates for production of microbial protein, enzymes, organic acids, monosodium glutamate, chitosan, etc. Additionally, sweet potato is a promising candidate for production of bioethanol. This review deals with the development of various products from sweet potato by application of bioprocessing technology. To the best of our knowledge, there is no review paper on the potential impacts of the sweet potato bioprocessing.     

A simple model to evaluate integrated vegetable production for food security in KwaZulu-Natal,South Africa

The objective of this study was to investigate the effectiveness of combining agricultural science with local knowledge in developing a simple model to evaluate vegetable production for food security and small-scale economic development. Four sites were selected for a preliminary survey to determine local knowledge about vegetable production using semi-structured interviews. Then, agronomic trials were conducted with a reduced number of participants representing an average household to grow popular vegetables identified in the surveys with the aim of testing the hypothesis of year-round organic production under virtual dryland conditions. A food security evaluation model based on farmer crop yield, home consumption and local market value was developed. The situation analysis showed that on average the farmers used their crops mainly for home consumption (~ 76%) compared to local market (~ 24%). Crop yields from 0.1 ha were found to be adequate for food security needs of an average household in the rural areas of South Africa. The food security values of maize (the staple crop) and cabbage (a popular vegetable) were found to be about 52%. The study revealed clearly that for a household of five persons, an average fresh vegetable crop yield of 19 to 27 t ha^- 1 can be produced per annum if production occurs all year round. The study proposes the first simple linear food security value model based on crop yield and utilisation with farmer participation.     

花生红薯复合饮料的研制

以花生和红薯为主要原料制作花生红薯保健饮料,研究了花生红薯比例、糖用量、乳化稳定剂3个因素对饮料品质的影响,确定了花生红薯饮料的最佳配方为,花生与红薯的比例1.5∶1,白砂糖用量6%,复配乳化稳定剂为,羧甲基纤维素钠1%,海藻酸钠1%,蔗糖酯SE1170用量0.8%。     

Biofortification of sweet potato for food and nutrition security in South Africa

South Africa has a diverse population, with some pockets of society being in a first world setup and other pockets in a third world impoverished setup. Food provision in impoverished societies is particularly crucial. Sweet potato (Ipomoea batatas (L.) Lam.) is a hardy crop and prominent in ensuring household food security; through its rich supply of energy, high yield potential and market value. In addition, orange-fleshed cultivars in particular are prominent in combating vitamin A deficiency due to high content of naturally bio-available β-carotene. This paper reviews interventions with regard to biofortification of sweet potato in South Africa towards addressing food and nutrition security. The focus was on the development of biofortified (high β-carotene content) cultivars and screening procedures for desired varietal traits; assessment of β-carotene, anti-oxidant and mineral content and the processing potential of orange-fleshed cultivars. Efficacy of orange fleshed sweet potato to improve vitamin A status was shown and positive effects of household production of orange-fleshed sweet potato, in conjunction with other β-carotene rich vegetables, on dietary intake, vitamin A status and food security were recorded. Dissemination efforts were initially focused on home gardens, which gradually expanded to subsistence production and enterprises. During 2014/15, over 1 million cuttings were disseminated and 5 to 40 small-scale commercial farmers in six provinces planted 0.25 to 1 ha of orange-fleshed sweet potato as means for income generation. In order to exploit the nutritional benefits of sweet potato and its potential to reduce vitamin A malnutrition and food insecurity, it is recommended that policy makers set directives to incorporate orange-fleshed sweet potato in government programs related to health, rural development, social development and agricultural production. There is a great need for investment in promotion of orange-fleshed sweet potato, particularly to consumers and retailers. Private–public partnerships and investment by private companies will be crucial for upscaling the impact of orange-fleshed sweet potato on food and nutrition security.     

粮食水溶性蛋白组成特点及体外结合胆酸盐能力比较

提取稻谷、小麦、大豆、玉米、马铃薯和甘薯等6种主要粮食水溶性蛋白,分析它们的组成特点及其在体外与胆酸盐结合的能力.大豆水溶性蛋白含量最高,小麦次之,马铃薯最低;稻谷、大豆和小麦的水溶性蛋白种类多,而甘薯的种类最少.各样品的水溶性蛋白对胆酸钠、脱氧胆酸钠和牛磺胆酸钠都具有吸附作用.在相同蛋白质质量的情况下,小麦水溶性蛋白吸附胆酸盐的能力最强,极显著性地大于其他5种粮食;稻谷和玉米之间、玉米和大豆之间的水溶性蛋白吸附胆酸盐的能力无显著性差异,而马铃薯、甘薯的水溶性蛋白吸附胆酸盐的能力则显著性低于其他样品.这些粮食水溶性蛋白吸附胆酸盐能力的差异主要与蛋白种类数和组成有关,低相对分子质量的水溶性蛋白对胆酸盐的结合能力可能比高相对分子质量的水溶性蛋白要强.     

Progress in Research and Development of Potato Staple Food Processing Technology

In 2014, potato production in China amounted to 96 million tons, which was the highest in the world. As one of the most important nutritional foods in the world, potato is rich in starch, dietary fiber, vitamins, minerals, etc. Potatoes stand barren environment, drought, saline, and alkaline environment, and cold weather, with a short growing season. These features make them the best rain-fed crops suitable for production even when the annual rainfall is below 400 mm. In 2013, the Chinese Ministry of Agriculture suggested a potato staple food strategy using potatoes to make Chinese traditional staple foods such as steamed bread, noodles, etc. Our research group carried out a study on processing technology of potato staple food, especially fermented staple food. Some new processing technologies of potato staple food have been investigated and developed. The aim of this paper is to give an overview of the possible effects of adding potato flour in the dough and of the microstructure characteristics, technological parameters, total polyphenol content, and antioxidant activity of staple foods. We also systematically describe the processing technology of potato staple foods, which may be of great importance in promoting further expansion of the potato-processing industry and increasing the economic benefit of the companies.     

Mining maize diversity and improving its nutritional aspects within agro‐food systems

Agro‐food systems are undergoing rapid innovation in the world and the system's continuum is promoted at different scales with one of the main outcomes to improve nutrition of consumers. Consumer knowledge through educational outreach is important to food and nutrition security and consumer demands guide breeding efforts. Maize is an important part of food systems. It is a staple food and together with rice and wheat, they provide 60% of the world's caloric intake. In addition to being a major contributor to global food and nutrition security, maize forms an important part of the culinary culture in many areas of Africa, the Americas, and Asia. Maize genetics are being exploited to improve human nutrition with the ultimate outcome of improving overall health. By impacting the health of maize consumers, market opportunities will be opened for maize producers with unique genotypes. Although maize is a great source of macronutrients, it is also a source of many micronutrients and phytochemicals purported to confer health benefits. The process of biofortification through traditional plant breeding has increased the protein, provitamin A carotenoid, and zinc contents of maize. The objective of this paper is to review the innovations developed and promoted to improve the nutritional profiles of maize and outcomes of the maize agro‐food system.     

Women and men farmer perceptions of economic and health benefits of orange fleshed sweet potato (OFSP) in Phalombe and Chikwawa districts in Malawi

Based on a qualitative study conducted in Chikwawa and Phalombe in Malawi, this paper looks at farmers perceived economic, health and social benefits of production, commercialization and consumption of orange fleshed sweet potato (OFSP). Findings demonstrate that perceived health and economic benefits were key determinants in adoption of OFSP varieties. Men and women are receptive to health and nutrition based promotion messages. Health benefits included increased energy to work, for sex, improved health, general wellbeing and cognitive development for children. Economic benefits included ability to invest income from selling of OFSP roots and vines in housing, purchase of livestock, food, and land. Income from OFSP enabled farmers to diversify into other cash crops. Women also mentioned increasing self-esteem due to increased incomes since they no longer needed to ask for money from their husbands to buy household consumables. However, men and women did not have equal access to and control of economic benefits and therefore women could not invest in large assets like cattle, land and agriculture equipment which could contribute to food security and are important to moving out of poverty. Interventions to increase farmer incomes should be designed in ways that allow women to actively participate and benefit. Since livestock are a key investment option and also contribute to food security and diversification, options for making sweet potato based silage for animal feed would be an important intervention especially for vines that would otherwise go to waste due to lack of markets.     

Application of the TOA-MD model to assess adoption potential of improved sweet potato technologies by rural poor farm households under climate change: the case of Kabale district in Uganda

Sweet potato technologies that increase productivity, such as drought resistant varieties and virus free planting material are being promoted in order to reduce the vulnerability of poor farm households to climate change. In this paper, the Trade-off Analysis, Minimum Data Model Approach (TOA-MD) was used to assess the adoption potential of these technologies by resource poor farmers under climate change in Uganda. The model was calibrated and validated using household survey data collected in 2009 from Kabale district. To simulate adoption potential, the base system data was generated from household data and adjusted to reflect impact of climate change on crop yields and prices by 2050. The percentage increase in yields resulting from the use of climate resilient sweet potato technologies were used to estimate yields for alternative systems based on the results from sweet potato trials by the National Agricultural Research Organization (NARO), Uganda. Adoption potential of sweet potato technologies varied across altitudes. Compared with the high and lower altitudes, adoption potential is lowest at moderate altitude despite higher yields and lower costs of production. Paying farmers to adopt new sweet potato technologies is economically rational at the higher and moderate altitudes but not at the lower altitudes. The provision of free planting material (subsidy) for the evaluated technologies resulted in a modest increase of 2 % in adoption potential. Therefore, providing this as a way of increasing adoption of sweet potato technologies to reduce vulnerability of poor farm households to climate change will have a very small impact. Instead, climate change adaptation policy should focus on creating enabling environments for farmers to market their produce so as to raise returns and reduce the opportunity costs of climate change adaptation strategies.     

Social relationships impact adoption of agricultural technologies: the case of food crop varieties in Timor-Leste

Factors related to adoption of new agricultural technologies have been given increasing attention, especially in developing countries where such technologies offer opportunities to increase food production. One of the most immediate ways to improve food production significantly is through the adoption of high yielding varieties of food crops, but rates of adoption are often low, especially among the rural poor. In Timor-Leste, improved varieties of food crops with yield advantages across all agro-ecological zones have been introduced. However, despite yield advantages, suitability and high levels of food insecurity, discontinuance occurs and adoption rates are low. To identify factors related to adoption of the improved varieties across agro-ecological zones, binary logistic regression was performed on data collected from 1511 rural households. The results identified several factors related to adoption and showed that their impact varied across agro-ecological zones. The factor most strongly related to adoption was having a relationship to a grower of an improved variety of food crop and the closeness of this relationship. Furthermore, the following factors were related to adoption with variation across agro-ecological zones: age; education; size of farming plots; travel time between household and farming plot; involvement with the programme developing the improved varieties of food crops and participation in groups and training programmes. Overall, the findings of this study emphasize that dissemination strategies should embrace social relationships and be sensitive to agro-ecological zones.     

促进玉米直链淀粉回生的甘薯淀粉晶种的筛选及表征

通过向四次回生的玉米直链淀粉中添加草酸侵蚀的四次回生的甘薯淀粉、甘薯直链和甘薯支链淀粉晶种(质量分数:1%),研究甘薯淀粉晶种对玉米直链淀粉回生的影响。结果表明,甘薯淀粉晶种明显促进了玉米直链淀粉回生长晶,其中甘薯直链淀粉晶种使得玉米直链淀粉回生率达到59.5%,比不添加晶种提高了19.3%。可见吸收光谱研究表明,甘薯淀粉晶种及长晶后的玉米直链淀粉均保持了双螺旋结构。X-射线研究表明草酸侵蚀后甘薯淀粉、甘薯直链淀粉、甘薯支链淀粉均为A+B型。将其分别添加到玉米直链淀粉中并长晶后的样品,结构均为B型。DSC研究表明,甘薯支链淀粉晶种具有最高的吸热焓,说明其晶体含量最高。三种晶种分别促进玉米直链淀粉长晶后的结构较为相似,晶体含量也较相近。该研究为提高淀粉的回生率、研究回生淀粉结晶结构提供良好的技术支持。     

The incorporation of sweet potato application in the preparation of a rice beverage

Summary To increase the industrial applications of sweet potato, a rice beverage was prepared by adding barley sprouts, sweet potato, or a mixture of barley sprouts and sweet potato (1:1). Amylases from barley sprouts and sweet potatoes had a similar hydrolysis pattern to β‐amylase. Heat stability of this enzyme in sweet potato was higher than that in barley. Reducing sugar content in the mixture of barley sprouts and sweet potato was higher than in either barley sprouts or sweet potato alone. After the preparation of the rice beverage, the maltose content of the mixture with barley sprouts, either barley sprouts and sweet potato, or sweet potato was 37.2, 44.1 and 40.3 mg mL^?1 after 6 h, respectively. The amylase activity in the mixture with barley sprouts and sweet potato decreased more than that of the mixture with only sweet potato. The use of sweet potato resulted in an increase of sweetness, flavour and improved preference in rice beverage.     

Evaluating the impact of improved maize varieties on food security in Rural Tanzania: Evidence from a continuous treatment approach

This paper investigates impact heterogeneity in the adoption of improved maize varieties using data from rural Tanzania. We used a generalized propensity-score matching methodology, complemented with a parametric econometric method to check the robustness of results. We found a consistent result across models, indicating that adoption increased food security, and that the impact of adoption varied with the level of adoption. On average, an increase of one acre in the area allocated to improved maize varieties reduced the probabilities of chronic and transitory food insecurity from between 0.7 and 1.2 % and between 1.1 and 1.7 %, respectively. Policies that increase maize productivity and ease farmers’ adoption constraints can ensure the allocation of more land to improved technologies and, in doing so, enhance the food security of households.     

几种原花青素的降血糖作用及与常见食品原料的结合研究

以4种不同来源的原花青素为研究对象,利用高通量淀粉浊度法测定其对α-淀粉酶和α-葡萄糖苷酶活力的抑制效果,研究其与常见食物原料之间的相互作用,为进一步开发降血糖主食提供理论依据。结果表明:葡萄籽与高粱麸皮原花青素对α-淀粉酶和α-葡萄糖苷酶活力抑制效果相对较好,蔓越莓与苹果原花青素对α-淀粉酶和α-葡萄糖苷酶活力抑制效果相对较差;食物中的主要成分与原花青素结合后会影响其对酶活力的抑制效果,常见食物中糯米、散装大米、高粱米等与葡萄籽原花青素结合明显,降低其对碳水化合物消化酶活力抑制效果,但玉米淀粉、木薯粉、马铃薯粉、生粉、米粉、小西米、小黄米、玉米片、红薯粉、黑米及黑豆与葡萄籽原花青素之间几乎不结合,是适宜发挥原花青素对碳水化合物消化酶活力抑制作用的食品原料。