Microalgae: a novel ingredient in nutrition

Microalgae are known for centuries, but their commercial large-scale production started a few decades ago. They can be grown in open-culture systems such as lakes or highly controlled close-culture systems, have higher productivity than the traditional crops and can be grown in climatic conditions and regions where other crops cannot be grown, such as desert and coastal areas. The edible microalgae are the green algae (chlorophyta) and the cyanobacteria. Microalgae contain substances of high biological value, such as polyunsaturated fatty acids, proteins, amino acids, pigments, antioxidants, vitamins and minerals. They are promising sources for novel products and applications and they can be used in the diet of humans and animals as natural foods with health benefits. Moreover, they can find use in the protection of the environment, as well as in pharmaceuticals, biofuel production and cosmetics.     

Factors affecting iron absorption and the role of fortification in enhancing iron levels

Iron is an important micronutrient required for a number of biological processes including oxygen transport, cellular respiration, the synthesis of nucleic acids and the activity of key enzymes. The World Health Organization has recognised iron deficiency as the most common nutritional deficiency globally and as a major determinant of anaemia. Iron deficiency anaemia affects 40% of all children between the ages of 6 and 59 months, 37% of mothers who are pregnant and 30% of women between the ages of 15 and 49 years worldwide. Dietary iron exists in two main forms known as haem iron and non-haem iron. Haem iron is obtained from animal sources such as meat and shows higher bioavailability than non-haem iron, which can be obtained from both plant and animal sources. Different components in food can enhance or inhibit iron absorption from the diet. Components such as meat proteins and organic acids increase iron absorption, while phytate, calcium and polyphenols reduce iron absorption. Iron levels in the body are tightly regulated since both iron overload and iron deficiency can exert harmful effects on human health. Iron is stored mainly as haemoglobin and as iron bound to proteins such as ferritin and hemosiderin. Iron deficiency affects individuals at increased risk due to factors such as age, pregnancy, menstruation and various diseases. Different solutions for iron deficiency are applied at individual and community levels. Iron supplements and intravenous iron can be used to treat individuals with iron deficiency, while various types of iron-fortified foods and biofortified crops can be employed for larger communities. Foods such as rice, flour and biscuits have been used to prepare fortified iron products. However, it is important to ensure the fortification process does not exert significant negative effects on organoleptic properties and the shelf life of the food product.     

Globalisation and transboundary risk regulation: Pesticides and genetically modified crops

Globalisation of food production systems and accompanying pressures for trade liberalisation are raising new issues for risk regulation and also placing greater demands on risk regulatory systems. Transboundary food-related risks are categorised here as 'traded' risks, subdivided into those which are product-based and those which are production system based. The international systems for regulating the risks of pesticide residues in food and of GM crops are summarised and examples are given of how the risks are monitored and evaluated. For GM crops and pesticides, although in different proportions, concerns focus on risks inherent in food products themselves and in the food production systems of which they form components. Different public motivations (self-interest versus fundamental values) underlie the expressions of concern and different approaches are needed for resolution and public reassurance in each case. We propose an approach which assigns legitimate and clearly specified roles to the two approaches, product based and production system based, which would elevate the debate about GM crops to a higher systemic level where it may have a greater chance of being resolved.     

Engineering plants for animal feed for improved nutritional value

Feed formulation to meet nutritional requirements of livestock is becoming increasingly challenging. Regulations have banned the use of traditional high-quality protein supplements such as meat-and-bone meal, pollution from animal excreta of N and P is an issue and antibiotics are no longer available as insurance against the impact of enteric infection and feed anti-nutritional factors. The improved genetic potential of livestock is increasing daily requirement for energy and protein (essential amino acids). To benefit from the enhanced growth potential of livestock diets with high nutrient density are needed that can be formulated from crops without increased cost. Genetic modification of commodity crops used to manufacture animal feed in order to improve the density and quality of available nutrients is a potential solution to some of these problems. Furthermore, crops may be used as biofactories to produce molecules and products used in animal feed with considerable reductions in manufacturing fixed costs. Nevertheless, there are considerable not insurmountable challenges, such as the creation of sufficient economic value to deliver benefit to all members in the feed production chain, which is an essential element of identity preserving and delivering the technology to livestock producers. Individual output traits in the major commodity crops may not provide sufficient value to adequately compensate all the members of the feed production chain. Successful adoption of output traits may rely on inserting combinations of agronomic input traits with specific quality traits or increasing the value proposition by inserting combinations of output traits.     

Absence of residues from crops irrigated with water treated with trifenmorph for schistosomiasis control

The fate of the molluscicide trifenmorph (N-tritylmorpholine) following its use in irrigation systems to control the intermediate hosts of schistosomes was studied by laboratory and field experiments. Laboratory studies with ¹⁴C-trifenmorph indicated that bean plants did not take up detectable residues when the soil in which they were grown was irrigated with water containing trifenmorph in concentrations likely to occur in the field. These laboratory studies have been complemented by field irrigation studies of growing crops in southern Africa and the Sudan. Residues of trifenmorph and its breakdown product triphenylmethanol could not be detected in the crops and the limit of detectability was 0.01-0.02 ppm. These results indicate that residues are not likely to be present in irrigated crops following the treatment of the irrigation water systems with trifenmorph.     

Estimation of undernutrition and mean calorie intake in Africa: methodology, findings and implications

Background

Agricultural science can address a population's vitamin, amino acid and mineral malnutrition through biofortification - agronomy, plant breeding and biotechnology to develop crops with high nutrient contents. Biofortified crop varieties should be grown in areas with populations at risk of nutrient deficiency and in areas where the same crop is already grown and consumed. Information on the population at risk of nutrient deficiency is rarely available for sub-national administrative units, such as provinces, districts, and municipalities. Nor is this type of information commonly analyzed with data on agricultural production. This project developed a method to identify populations at risk of nutrient deficiency in zones with high crop production, places where biofortification interventions could be targeted.

Results

Nutrient deficiency risk data were combined with crop production and socioeconomic data to assess the suitability of establishing an intervention. Our analysis developed maps of candidate sites for biofortification interventions for nine countries in Latin America and the Caribbean. Results for Colombia, Nicaragua, and Bolivia are presented in this paper. Interventions in northern Colombia appear promising for all crops, while sites for bean biofortification are widely scattered throughout the country. The most promising sites in Nicaragua are found in the center-north region. Candidate sites for biofortification in Bolivia are found in the central part of the country, in the Andes Mountains. The availability and resolution of data limits the analysis. Some areas show opportunities for biofortification of several crops, taking advantage of their spatial coincidence. Results from this analysis should be confirmed by experts or through field visits.

Conclusion

This study demonstrates a method for identifying candidate sites for biofortification interventions. The method evaluates populations at risk of nutrient deficiencies for sub-national administrative regions, and provides a reasonable alternative to more costly, information-intensive approaches.     

Hybridomas as a source of antibodies

Hybridomas, the progeny of fusion between antibody-secreting spleen cells and myeloma cells, produce large quantities of a single species of antibody. They are an ideal source of serologic reagents since they can be grown in tissue culture, frozen, stored, and recovered when needed. Impending applications include production of monoclonal antibodies to a wide variety of serum components and pathogens.     

Production of antibodies and antibody fragments in plants

Our current knowledge allows the generation of transgenic plants that efficiently produce heterologous proteins from plant, bacterial, fungal or animal origin. Among all types of recombinant proteins, antibodies are particularly attractive because of their ability to specifically recognize and bind virtually any type of antigen. Plants show several advantages as a large-scale antibody production system: they can be grown easily and inexpensively in large quantities that can be harvested, stored and processed by using existing infrastructures. Isolation and purification of plant-made antibodies, if necessary, allow fundamental, industrial, and therapeutical applications. In the past, we and others have successfully generated antibody-producing plants. The maximal accumulation levels of antibodies and antibody fragments that we observed are 1-5% of the extracted proteins. Currently, several biotechnological companies grow field crops to produce antibodies for ex planta applications on an industrial scale.     

运动员保健食品—健力饼干的研究

本文介绍一种新型保健食品—健力饼干。该食品配方为粗细粮合理搭配,适量强化维生素B_1、B_2、E;微量元素铁、锌及磷脂。经营养成分分析,蛋白质含量为10.03％,所含八种人体必需氨基酸及其比值基本符合FAO1973年提出的理想氨基酸模式及其比值。通过营养评价试验,蛋白质的表观消化率为87.74％,净蛋白利用率为74.54％,生物价为79.27％,蛋白质功效比为2.97。在运动员中试用观察结果表明,食用健力饼干可提高运动员体内血红蛋白含量及必需元素——锌、铁、钙、磷的含量。     

Polyunsaturated fatty acids of germ cell membranes,glutathione and blutathione-dependent enzyme-PHGPx: from basic to clinic

The lipid metabolism in sperm cells is important both for energy production and for cell structure. A special composition of membrane phospholipids, rich in polyunsaturated fatty acids (PUFA), and the different composition of sperm and immature germ cell membrane are described and discussed. Testis germ cells as well as epididymal maturing spermatozoa are endowed with enzymatic and non-enzymatic scavenger systems to prevent lipoperoxidative damage. Catalase, superoxide dismutase, and glutathione-dependent oxidoreductases are present in variable amounts in the different developmental stages. Phospholipid hydroperoxide glutathione peroxidase (PHGPx) activity and roles in caput and cauda epididymal sperm cells are discussed. Also seminal plasma has a highly specialized scavenger system that defends the sperm membrane against lipoperoxidation and the degree of PUFA insaturation acts to achieve the same goal. Systemic predisposition and a number of pathologies can lead to an anti-oxidant/pro-oxidant disequilibrium. Scavengers, such as glutathione can be used to treat these cases as they can restore the physiological constitution of PUFA in the cell membrane.     

重金属迁移及其对农作物影响的研究进展

重金属可以通过各种形态发生迁移,不同的化学形态其迁移的机制和毒害程度完全不一样。随着矿产资源的开发和环境污染的多样化,大量的重金属元素释放进入环境,造成了严重的土壤和水体污染,并直接导致农作物如粮食、蔬菜和水果中重金属元素含量的升高。随着生活水平的提高以及对农产品污染通过食物链的传递给人体造成危害的认识加深,人们对农产品质量的要求也越来越高。重金属污染的研究已成为一个令人瞩目的新领域。不同农作物对重金属的吸收和富集能力也不尽相同,作者详细阐述了重金属的迁移机制及其对农作物的污染危害,为农作物的安全生产提供科学依据。     

Everyday strategies for handling food safety concerns: a qualitative study of distrust,contradictions, and helplessness among Taiwanese women

Past research has provided evidence of the important role that trust plays in people’s decisions regarding food consumption. This study examines the reasons for people’s distrust in food production systems and how they conceptualise and handle food-related risks in everyday life in a context in which food scandals have occurred frequently. In-depth interviews were conducted with 39 married Taiwanese women. Our findings indicated that the women believed that collusion commonly occurs between business and government entities and that such collusion frequently leads to food scandals. However, despite their distrust in the food system and suspicion towards the government, the women generally still relied on food labels and certifications when making food purchasing decisions. These ‘in-between’ strategies were formed by their knowledge and experiences of day-to-day living in Taiwan, and while the strategies may seem somewhat self-contradictory, they can be understood as empowering people to protect themselves and their families in circumstances of general distrust and helplessness.     

Women, food and nutrition in Africa: perspective from Senegal

If proper nutrition and good health for all Africans is to be attained by the year 2000, then several hard to control socio-economic factors must be addressed. Simply put they are: illiteracy, financial resources, parasitic and infectious disease control, and improper eating habits. However even economic progress is no guarantee of improvement for it has disadvantages all its own such as a widening gap between the urban and rural population in terms of their standard of living, and the rural exodus of people which results in reduced food production. While new crops may take the place of the traditional ones, many of these are grown near urban centers to feed the inhabitants or are exported for profit. The result is that the rural population suffers nutritionally. It is for all these reasons that the nutritional situation in Africa must be considered critical by national and international relief and development organizations. Other factors are the Sahelian drought which has been raging since 1972 and the oil crisis which has affected the balance of payments of foreign aid loans. The focus of this article is on the nutritional effects these problems have had on the rural women of Africa. The role of women as food producers, processors and household food providers area all considered. From this discussion, some consideration of the outlook for nutrition in Africa can be addressed. It is the author's final conclusion that educating the women of Africa about improved farming and veterinary methods will best help raise the standard of living for their households.     

制革工业园区周围小麦和玉米的铬污染评价

[目的]了解制革工业园区周围粮食的铬污染程度,为粮食铬污染防治策略制定提供背景数据。[方法]采集制革园区周围农田所产粮食（36份）和对照区种植粮食样品（22份）,分别检测其铬含量,采用《食品中污染物限量》（GB2762-2005）计算其超标率,采用单因子污染指数法评价粮食中铬污染程度。[结果]制革工业园区周围农田所产粮食的铬含量为0．74mg／kg,而对照区为0．18mg／kg,差异有统计学意义（P〈O．05）;该工业园区周围种植粮食铬超标率为16．66％,明显高于对照区（0％）（P〈0．05）;小麦和玉米单因子污染指数平均值均小于l。[结论]该制革工业园区周围部分种植点粮食受到了铬污染,可能会对暴露人群构成危害。     

A comparison of chemical composition and nutritional value of organically and conventionally grown plant derived foods

The consumption of organic food has been increasing all over the world. Due to this fact, there are growing numbers of scientific studies examining the nutritional value of organic food. The aim of this review is to provide an overall picture of the beneficial and harmful nutritional content of organically and conventionally produced crops based on existing international comparative surveys. Furthermore, the authors attempt to define the relationship between organic and conventional food production systems and the nutritional value of food products as well as the consumption of organic and conventional diets which have important human health implications. Organic crops contain a significantly higher amount of certain antioxidants (vitamin C, polyphenols and flavonoids) and minerals, as well as have higher dry matter content than conventional ones. Moreover, there is a lower level of pesticide residues, nitrate and some heavy metal contaminations in organic crops compared to conventional ones. There is a relationship between the different fertilisation and plant protection methods of these two plant production systems and the nutritional composition of crops. Consequently, it can be concluded that organically produced plant derived food products have a higher nutritional value, including antioxidants than conventional ones. Furthermore, due to the fact that there is a lower level of contamination in organic crops, the risk of diseases caused by contaminated food is significantly reduced.     

Nutritional challenges and countermeasures for space travel

There has been a reinvigoration of public interest in space exploration in what has been deemed the new space race, which aims to eventually take humans to Mars in the 2030s. This type of Earth‐independent deep space mission presents a multitude of challenges for providing astronauts with adequate nutrition, which are not currently posed by our presence in low earth orbit. For example, there are technical challenges associated with providing enough food with sufficient nutrient content, bioavailability and increased shelf life. Environmental stressors may also impact physiology and in turn affect nutritional status. Increased exposure of radiation, for example, causes changes in the gut and liver that might facilitate nutrient deficiency. Current or potential countermeasures for these challenges are explored including the use of bio‐regenerative systems such as growing crops or biomass, or inducing torpor to reduce nutritional needs. Additionally, the beneficial role of nutrients has also been explored for alleviating the harmful effects of spaceflight exposure. It is clear that such countermeasures will be necessary to maintain astronaut health during long‐duration missions to potentially counteract physiological stresses and to allow us to continue pushing the boundaries of space exploration.     

Trans fatty acids– Metabolic and nutritional significance

'Trans' fatty acids are unsaturated acids with special structural features that occur naturally in dietary fats from animal and plant sources and in fats processed by catalytic hydrogenation. They are readily metabolized by the human body. Thus, although when consumed in the diet they are incorporated into body fat (including depot and milk fats), they are subject to rapid 'turnover'. In physical properties, trans monounsaturatedfatty acids are intermediate between cis-monounsaturated and saturated acids, and they tend to be treated either as saturated or cis-monounsaturated acids in metabolic pathways. The author argues in this article that any adverse effects on health or metabolism that may have been observed can be ascribed to an imbalance between the intake of trans and essential fatty acids. Such imbalances, could also occur with non-essential fatty acids other than trans fats. Normally, the amounts eaten in average diets would not pose serious problems and only when products have excessively high trans contents and make a significant contribution to the diet need trans acids be highlighted on labels.     

Cultivation conditions and selenium fertilization alter the phenolic profile, glucosinolate, and sulforaphane content of broccoli

Broccoli is a food often consumed for its potential health-promoting properties. The health benefits of broccoli are partly associated with secondary plant compounds that have bioactivity; glucosinolates and phenolic acids are two of the most abundant and important in broccoli. In an effort to determine how variety, stress, and production conditions affect the production of these bioactive components broccoli was grown in the greenhouse with and without selenium (Se) fertilization, and in the field under conventional or organic farming procedures and with or without water stress. High-performance liquid chromatography/mass spectrometry was used to separate and identify 12 primary phenolic compounds. Variety had a major effect: There was a preponderance of flavonoids in the Majestic variety, but hydroxycinnamic esters were relatively more abundant in the Legacy variety. Organic farming and water stress decreased the overall production of phenolics. Se fertilization increased glucosinolates in general, and sulforaphane in particular, up to a point; above that Se fertilization decreased glucosinolate production. Organic farming and water stress also decreased glucosinolate production. These data show environmental and genetic variation in phenolics and glucosinolates in broccoli, and warn that not all broccoli may contain all health-promoting bioactive components. They further show that selection for one bioactive component (Se) may decrease the content of other bioactive components such as phenolics and glucosinolates.     

The problem with nutritionally enhanced plants

Among the next generation of genetically modified (GM) plants are those that are engineered to produce elevated levels of nutritional molecules such as vitamins, omega-3 fatty acids, and amino acids. Based upon the U.S. current regulatory scheme, the plants and their products may enter our food supply without any required safety testing. The potential risks of this type of GM plant are discussed in the context of human health, and it is argued that there should be very careful safety testing of plants designed to produce biologically active molecules before they are commercially grown and consumed. This will require a mandatory, scientifically rigorous review process.