Mycotoxin contamination of foods in Southern Africa: A 10-year review (2007–2016)

Major staple foods in Southern Africa are prone to mycotoxin contamination, posing health risks to consumers and consequent economic losses. Regional climatic zones favor the growth of one or more main mycotoxin producing fungi, Aspergillus, Fusarium and Penicillium. Aflatoxin contamination is mainly reported in maize, peanuts and their products, fumonisin contamination in maize and maize products and patulin in apple juice. Lack of awareness of occurrence and risks of mycotoxins, poor agricultural practices and undiversified diets predispose populations to dietary mycotoxin exposure. Due to a scarcity of reports in Southern Africa, reviews on mycotoxin contamination of foods in Africa have mainly focused on Central, Eastern and Western Africa. However, over the last decade, a substantial number of reports of dietary mycotoxins in South Africa have been documented, with fewer reports documented in Botswana, Lesotho, Malawi, Mozambique, Zambia and Zimbabwe. Despite the reported high dietary levels of mycotoxins, legislation for their control is absent in most countries in the region. This review presents an up-to-date documentation of the epidemiology of mycotoxins in agricultural food commodities and discusses the implications on public health, current and recommended mitigation strategies, legislation, and challenges of mycotoxin research in Southern Africa.     

Nutritional properties of einkorn wheat (Triticum monococcum L.)

The hulled wheat einkorn (Triticum monococcum L. ssp. monococcum), a staple food of early farmers for many thousand years, today is cropped only in small areas of the Mediterranean region and continental Europe. Increasing attention to the nutritional quality of foods has fostered renewed interest in this low‐impact crop. The reappraisal of einkorn quality evidenced that this ancient wheat has some dietary advantages over polyploid wheats. Einkorn wholemeal is poor in dietary fibre but rich in proteins, lipids (mostly unsaturated fatty acids), fructans and trace elements (including zinc and iron). The good concentration of several antioxidant compounds (carotenoids, tocols, conjugated polyphenols, alkylresorcinols and phytosterols) and low β‐amylase and lipoxygenase activities (which limit antioxidant degradation during food processing) contribute to the excellent nutritional properties of its flour, superior to those of other wheats. Conversely, einkorn has relatively low bound polyphenol content and high polyphenol oxidase activity. In spite of eliciting weaker toxic reactions than other Triticum species, einkorn is not suitable for coeliacs. Current trends towards the consumption of functional foods suggest that this cereal may still play a significant role in human consumption, especially in the development of new or special foods with superior nutritional quality. © 2013 Society of Chemical Industry     

The impact of agricultural input subsidies on food and nutrition security: a systematic review

Agricultural input subsidies, a form of social protection, are often considered an important means of improving agricultural productivity in low- and middle-income countries. However, their effectiveness and efficiency remains contentious with respect to productivity, economic and consumer welfare measures, as well as food and nutrition security. This is exacerbated by a weak evidence base, including no review focused on the impact of agricultural input subsidies on food security and nutrition. Further, where studies have considered nutritional outcomes of agricultural input subsidy interventions, this has often been in regard to changes in consumption of the targeted staple food, measured in terms of calorie consumption or a similar measure of changes in energy availability, ignoring other aspects of malnutrition, including impacts from dietary diversity. This wider consideration of impacts from dietary diversity is important, given the increasing recognition in nutrition policy of its importance. We address this gap in the literature with a review of the evidence on the impact of agricultural input subsidy programmes on nutrition and nutrition-related health in low- and middle-income countries, mapping this evidence against a conceptual framework of the mediating pathways.     

马铃薯主粮化与马铃薯全粉及其生产线

马铃薯不但营养价值高,富含膳食纤维以及人体必需的多种氨基酸,而且脂肪和糖分含量又低。推进马铃薯主粮化,就是将马铃薯加工成适合国人消费习惯的馒头、面条、米粉,实现由副食消费向主食消费转变,逐渐成为稻谷、小麦、玉米之后的第四大主粮。这既有利于改善全体国民膳食结构,又有利于提高人民健康水平。马铃薯全粉及马铃薯全粉生产线将是实施马铃薯主粮化的一把金钥匙。      

Skyfarming an ecological innovation to enhance global food security

Population growth increases the demand for food and thus leads to expansion of cultivated land and intensification of agricultural production. There is a definite limit to both of these options for food security and their multiple negative effects on the environment undermine the aim for sustainability. Presently the impact of the Green Revolution on crop production is levelling off at high yields attained and even the potential of large scale irrigation programmes and transgenic crops seem to be limited in view of the expected increase in demand for food. Moreover, climate change threatens to affect agricultural production across the globe. Skyfarming represents a promising approach for food production that is largely environment independent and therefore immune to climate change. Optimal growing conditions, shielded from weather extremes and pests are aimed at raising plant production towards the physiological potential. Selecting rice as a pioneer crop for Skyfarming will not only provide a staple for a large part of the global population, but also significantly reduce the greenhouse gas emission caused by paddy cultivation. Multiplication of the benefits could be achieved by stacking production floors vertically. In Skyfarming the crop, with its requirements for optimal growth, development and production, determines the system’s design. Accordingly, the initial development must focus on the growing environment, lighting, temperature, humidity regulation and plant protection strategies as well as on the overall energy supply. For each of these areas potentially suitable technologies are presented and discussed.     

Worldwide aflatoxin contamination of agricultural products and foods: From occurrence to control

Aflatoxins represent a global public health and economic concern as they are responsible for significant adverse health and economic issues affecting consumers and farmers worldwide. Produced by fungal species from the Aspergillus genus, aflatoxins are a toxic, mutagenic, and carcinogenic group of fungal metabolites that routinely contaminate food and agricultural products. Climate and diet are essential factors in the aflatoxin contamination of food and subsequent human exposure process. Countri es with warmer climates and staple foods that are aflatoxin-susceptible shoulder a substantial portion of the global aflatoxins burden. Enactment of regulations, prevention of pre- and postharvest contamination, decontamination, and detoxification have been used to prevent human dietary exposure to aflatoxin. Exploiting their chemical and structural properties, means are devised to detect and quantify aflatoxin presence in foods. Herein, recent developments in several important aspects impacting aflatoxin contamination of the food supply, including: fungal producers of the toxin, occurrence in food, worldwide regulations, detection methods, preventive strategies, and removal and degradation methods were reviewed and presented. In conclusion, aflatoxin continues to be a major food safety problem, especially in developing countries where regulatory limits do not exist or are not adequately enforced. Finally, knowledge gaps and current challenges in each discussed aspect were identified, and new solutions were proposed.     

Skyfarming an ecological innovation to enhance global food security

Population growth increases the demand for food and thus leads to expansion of cultivated land and intensification of agricultural production. There is a definite limit to both of these options for food security and their multiple negative effects on the environment undermine the aim for sustainability. Presently the impact of the Green Revolution on crop production is levelling off at high yields attained and even the potential of large scale irrigation programmes and transgenic crops seem to be limited in view of the expected increase in demand for food. Moreover, climate change threatens to affect agricultural production across the globe. Skyfarming represents a promising approach for food production that is largely environment independent and therefore immune to climate change. Optimal growing conditions, shielded from weather extremes and pests are aimed at raising plant production towards the physiological potential. Selecting rice as a pioneer crop for Skyfarming will not only provide a staple for a large part of the global population, but also significantly reduce the greenhouse gas emission caused by paddy cultivation. Multiplication of the benefits could be achieved by stacking production floors vertically. In Skyfarming the crop, with its requirements for optimal growth, development and production, determines the system??s design. Accordingly, the initial development must focus on the growing environment, lighting, temperature, humidity regulation and plant protection strategies as well as on the overall energy supply. For each of these areas potentially suitable technologies are presented and discussed.     

小米营养成分制备方法研究进展

小米是我国的传统栽培作物,其种植面积广,栽培历史悠久,具有生长周期短和价格低廉的优点,是中国北方人民的主粮之一。小米中含有多种生物活性成分,如膳食纤维、黄色素、米糠油、多酚、多糖、功能性蛋白和多肽等,具有降血糖、降血压、抗溃疡、抗氧化、抗癌、抗菌、抗疲劳、促进伤口愈合、增强免疫力、肝损伤保护和通便等生物功能。通过对小米中营养成分的制备,能提高小米附加值,增加农民收入,促进农业经济发展。本文对小米营养成分特点、制备方法及其在食品工业中的应用进行了综述,旨在为小米深加工和产业化发展提供参考。     

Cadmium accumulation in pak choi (Brassica chinensis L.) and estimated dietary intake in the suburb of Hangzhou city,China

The total content of cadmium and its distribution between leaves and roots were investigated for pak choi (Brassica chinensis L.), which was grown in a contaminated area of Hangzhou city, China. Results showed that cadmium concentrations in 90% of samples exceeded the Chinese tolerance limit for food. Although roots of pak choi had a higher concentration of cadmium than leaves, leaf tissue (the edible part) accumulated over 80% (on average) of the whole plant cadmium burden due to the greater biomass in leaf tissue. Since pak choi is the staple vegetable in the study area and of great relevance to human health, the dietary intake of cadmium and calculated risk indexes to local residents through the food chain were determined.     

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.     

Natural Occurrence of Mycotoxins in Food and Feed: Pakistan Perspective

Fungi are commonly present in the environment and can grow under favorable conditions on an extensive variety of substrates. During harvesting, handling, storage, and distribution, agricultural commodities are subjected to infection by toxigenic molds, which may cause spoilage and produce toxic metabolites called mycotoxins. Fungal contamination of various food commodities with consequent exposure of the community to mycotoxins is a hazard that may exist depending on environmental factors, crop health, and soil conditions. Mycotoxins represent serious consequences due to substantial economic loss and risk to health. The environmental conditions of Pakistan with its mostly warm temperature are conducive to growth of toxigenic fungi resulting in mycotoxin production in different food items. Moreover, the poor conditions of storage and deficiency in regulatory measures in food quality control worsen the situation in the country. This review encompasses mycotoxin contamination of food and feed in Pakistan. High concentrations of mycotoxins are found in some commodities that are used on a daily basis in Pakistan, which may be a concern depending on dietary variety and health conditions of individuals in the population. Therefore, the mycotoxin contamination of foodstuff with exceeding levels represents a serious health hazard for the local population. There is a need to conduct more studies to analyze mycotoxin occurrence in all types of food commodities throughout the country. For consumer safety and the country's economy, the regulatory authorities should take into account this issue of contamination, and control strategies should be implemented and the quality control system of food improved.     

In vitro bioavailability of iron and calcium in cereals and derivatives: A review

Cereals are a staple food in both developed and developing countries, and are considered to be the best vehicle for iron and calcium fortification, as an important strategy for combating dietary deficits. Inadequate dietary intake of iron and calcium is related to a number of disease conditions such as anemia, osteoporosis, hypertension, and different cancers. From a nutritional point of view, it is interesting to know not only the amount of minerals consumed, but also their bioavailability. The present study reviews the current knowledge on the in vitro bioavailability of iron and calcium in cereals, placing emphasis on the methodologies used and on the influence of dietary factors and food processing.     

Utilization Potentials of Cassava in Nigeria: The Domestic and Industrial Products

Cassava (Manihot esculenta) is an important food crop in the tropics—a major carbohydrate staple consumed in various forms by humans. Furthermore, its usage as a source of ethanol for fuel, energy in animal feed, and starch for industry is increasing. Given that cassava represents a valuable subsistence and cash crop in many countries, its domestic and industrial potential needs to be fully exploited. Processing of cassava reduces the moisture content and converts it into a more durable and stable product. Women traditionally process cassava, although it could be processed at the small, medium, or industrial scale. This article discusses the major Nigerian domestic products as well as the potential industrial products of cassava that are yet to be produced locally and the machines used in their production. Although improved technology is one of the keys to increasing the productivity of micro-enterprises and generating broad-based, sustainable economic growth, the extent to which a given technology is acceptable to a given culture may depend on a number of considerations beyond the mechanical efficiency of the device. These topics are discussed and recommendations are suggested to encourage the establishment of more cassava based industries.     

Crops that feed the world 5. Sweetpotato. Sweetpotatoes for income and food security

Sweetpotato (Ipomoea batatas L. Lam) is a tuber crop of immense potential as it produces more edible energy on marginal land than any other major food crop. As well as this useful property it can withstand adverse abiotic and biotic stresses and does not require intensive care. It therefore plays an important role in the economy of poor households where it acts as a major source of subsistence and is considered to be a ‘famine relief crop’. Besides this important function, the crop has immense industrial value for extraction of starch and production of animal feed. For all these reasons sweetpotato has great possibilities for enhancing food and nutrition security in developing and underdeveloped countries where most of the farmers’ holdings belong to the small and marginal categories. Although the crop is assuming greater significance owing to the ever-increasing population its importance is still underestimated and, unlike most staples, fails to attract sufficient attention of agricultural researchers throughout the tropics and subtropics. With greater attention and more collaborative research, there could be considerable improvements in the genetics of the crop and its husbandry which, together, would allow it to fulfill a wide range of needs in these areas of the world.     

马铃薯全粉制备、性质和主食化加工研究进展

近年来,马铃薯全粉在加工产业链中占有着十分重要的地位,2015年农业部把马铃薯主粮化工作列入重要议程。马铃薯营养价值丰富,主粮化有助于改善和丰富我国居民膳食营养结构。总结了马铃薯全粉的制备、性质、食品加工的国内外研究概况,并对发展前景进行了展望。      

Health‐Affecting Compounds in Brassicaceae

ABSTRACT: Brassicaceae vegetables are considered to be a staple food in many areas all over the world. Brassica species are not only known for their high fat and protein contents for human and animal consumption, but Brassicaceae vegetables are recognized as a rich source of nutrients such as vitamins (carotenoids, tocopherol, ascorbic acid, folic acid), minerals (Cu, Zn, P, Mg, among others), carbohydrates (sucrose and glucose), amino acids (for example, L‐alanine, L‐aspartic acid, L‐glutamic acid, L‐glutamine, L‐histidine, L‐methionine, L‐phenylalanine, L‐threonine, L‐tryptophan, and L‐valine), and different groups of phytochemicals such as indole phytoalexins (brassinin, spirobrassinin, brassilexin, camalexin, 1‐methoxyspirobrassinin, 1‐methoxyspirobrassinol, and methoxyspirobrassinol methyl ether), phenolics (such as feruloyl and isoferuloylcholine, hydroxybenzoic, neochlorogenic, chlorogenic, caffeic, p‐coumaric, ferulic, and sinapic acids, anthocyanins, quercetin, and kaempferol), and glucosinolates (mainly glucoiberin, glucoraphanin, glucoalyssin, gluconapin, glucobrassicanapin, glucobrassicin, gluconasturtiin, and neoglucobrassicin). All of these phytochemicals contribute to the reported antioxidant, anticarcinogenic, and cardiovascular protective activities of Brassica vegetables. However, not all members of this family are equal from a nutritional viewpoint, since significant qualitative variations in the phytochemical profiles of Brassica species and varieties suggest differences in the health‐promoting properties among these vegetables. In this article, Brassica phytochemicals with their nutritional value and health‐promoting activities are discussed to give an overview of the literature for Brassica as a staple crop.     

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.     

Aflatoxigenic fungi and mycotoxins in food: a review

Abstract

Food contamination is a common phenomenon in the production, distribution and consumption of processed and agricultural commodities all over the world. Food safety is now taking the frontal stage in food production, processing and distribution. This study assessed the presence of aflatoxigenic fungi and mycotoxins in foods, occurrence, control, socio-economic and health implications. This study also gave comprehensive information on the safety and mycological quality of foods as well the effect on the people and economy of various countries. The review revealed the various aflatoxigenic fungi in foods, their distribution in agricultural produce and their effects on reduction in yield and quality with attendant consumer health implications and resulting significant economic losses. In developing countries, majority of the people do not know the inherent dangers of consuming mouldy produce or food contaminated with fungi and moulds with possible contamination by mycotoxigenic fungi because of lack of awareness about the danger involved. In view of this, there is need for general and public education to sensitise the people on the economic and health hazards posed by mycotoxins. Control measures such as good agricultural practices, crop selection, proper washing and cooking practices of food commodities should be emphasized to the people. Regulatory control, fast and effective analyses and detection, good produce handling and storage should be encouraged as this will assist in mitigating the side effects of mycotoxins in foods particularly in the tropical and sub-tropical countries, and in Africa nations where there is enabling environment that promotes fungal growth, shortage of food and drought of modern storage and processing infrastructures.     

The industrial applications of cassava: current status,opportunities and prospects

Cassava (Manihot esculenta Crantz) is a drought‐tolerant, staple food crop that is grown in tropical and subtropical areas. As an important raw material, cassava is a valuable food source in developing countries and is also extensively employed for producing starch, bioethanol and other bio‐based products (e.g. feed, medicine, cosmetics and biopolymers). These cassava‐based industries also generate large quantities of wastes/residues rich in organic matter and suspended solids, providing great potential for conversion into value‐added products through biorefinery. However, the community of cassava researchers is relatively small and there is very limited information on cassava. Therefore this review summarizes current knowledge on the system biology, economic value, nutritional quality and industrial applications of cassava and its wastes in an attempt to accelerate understanding of the basic biology of cassava. The review also discusses future perspectives with respect to integrating and utilizing cassava information resources for increasing the economic and environmental sustainability of cassava industries. © 2017 Society of Chemical Industry     

Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong total diet study

The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites – organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites – is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared “as consumed”. A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 μg kg^?1) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population.