Organic food

“Organic” or “organically grown” foods are commonly represented as “food grown without pesticides; grown without artificial fertilizers; grown in soil whose humus content is increased by the additions of organic matter; grown in soil whose mineral content is increased with applications of natural mineral fertilizers; which has not been treated with preservatives, hormones, antibiotics, etc.” The substitution of “organic” for “chemical” fertilizers during the growth of plants produces no change in the nutritional or chemical properties of foods. All foods are made of “chemicals.” Traces of pesticides have been reported to be present in about 20 to 30% of both “organic” and conventional foods. These traces are usually within the official tolerance levels. Such levels are set low enough to protect consumers adequately. Indeed, there is no record of a single case of injury to a consumer resulting from the application of pesticides to food crops at permitted levels. There is no method for distinguishing between “organic” and conventional foods. The use of the term “organic” is a promotional device. Prices of “organic” foods tend to be higher than those of their conventional counterparts. A series of controlled tests showed that conventional foods were superior to corresponding “health foods” in terms of odor, color, texture, and flavor.     

Organic food and the impact on human health

In the last decade, the production and consumption of organic food have increased steadily worldwide, despite the lower productivity of organic crops. Indeed, the population attributes healthier properties to organic food. Although scientific evidence is still scarce, organic agriculture seems to contribute to maintaining an optimal health status and decreases the risk of developing chronic diseases. This may be due to the higher content of bioactive compounds and lower content of unhealthy substances such as cadmium and synthetic fertilizers and pesticides in organic foods of plant origin compared to conventional agricultural products. Thus, large long-term intervention studies are needed to determine whether an organic diet is healthier than a diet including conventionally grown food products. This review provides an update of the present knowledge of the impact of an organic versus a conventional food diet on health.     

有机食品方兴未艾

<正> 随着工农业生产的发展和人口的增加,环境污染、资源过度的开采及生态破坏的日趋严重,人们保护环境的呼声日益高涨,有关专家认为,全球“有机食品”生产方兴未艾。 在海外,有心人稍稍留意一下超级市场的货架,就会发现“有机食物”热潮早已降临。最明显的是蔬菜、水果货架上常常有三五种菜果的价码牌上醒目地标着“有机”二字,如洋葱、萝卜、黄瓜、芹菜、西瓜、葡萄等。这些食品的外观与旁边摆着相同品种的普通菜果并没有什幺两样,但价格却普遍高出20～30％,有的     

Use of fertilizers and the quality of wheat protein

The fractional and amino acid composition, as well as efficacy, net utilization and nitrogen retention ratios of protein from wheat grown under the conditions of introducing different fertilizers into the soil were studied in experiments on rats. It was found that the biological value of protein from wheat grown with the use of organic and organomineral fertilizers which were introduced into the soil on the basis of a gradual increase in their amounts appeared to exceed that from wheat harvested in the control area. Mineral fertilizers provided a higher content of protein, with its quality being virtually unchanged. The differences in the biological value confirm the respective changes in the content of protein and its fractions in the blood serum of experimental animals which received over a month the same wheat as a constituent of the balanced diets. The absence of good agreement between the chemical composition of protein and its biological value allows a conclusion about the desirability of research into the biological value of food wheat with due regard for the fertilizers introduced.     

Identification of irradiated foods by the thermoluminescence of mineral contamination

This investigation assessed the radiation-induced thermoluminescence (TL) of food minerals for identifying irradiated foods. Mineral contamination, rather than the inherent mineral content, of foods was studied. Positive identification of foods given 1-10-kGy doses depends on the contents and composition of the mineral contamination and the time span between irradiation and TL analysis. All 20 irradiated spice and herb samples could be identified without comparing them with unirradiated material. Three out of 60 lots of spices and herbs examined so far were so pure that the mineral contents were too low to allow TL analysis. If the soil where potatoes are grown contains feldspars, sprout inhibition treatment with 100-200-Gy doses can also be detected for up to one year, using the 90-250 degrees C low-temperature part of the TL spectrum for evaluation.     

Nitrate and nitrite content of food products of plant origin grown with the use of mineral fertilizers

Introduction of mineral fertilizers into soil results in the nitrate accumulation in the vegetables grown in this soil. However, under conditions of the utilization of nitrogen fertilizers in a dose of 300 kg/hectar in the soil of Byelorussia, the nitrate content in vegetables does not exceed the permissible value. No direct relationship has been established between the accumulation of nitrates and nitrites in the vegetables and cereals and the dose of mineral fertilizers and nitrite accumulation in the soil.     

A comparison of the nutritional value, sensory qualities, and food safety of organically and conventionally produced foods

Given the significant increase in consumer interest in organic food products, there is a need to determine to what extent there is a scientific basis for claims made for organic produce. Studies comparing foods derived from organic and conventional growing systems were assessed for three key areas: nutritional value, sensory quality, and food safety. It is evident from this assessment that there are few well-controlled studies that are capable of making a valid comparison. With the possible exception of nitrate content, there is no strong evidence that organic and conventional foods differ in concentrations of various nutrients. Considerations of the impact of organic growing systems on nutrient bioavailability and nonnutrient components have received little attention and are important directions for future research. While there are reports indicating that organic and conventional fruits and vegetables may differ on a variety of sensory qualities, the findings are inconsistent. In future studies, the possibility that typical organic distribution or harvesting systems may deliver products differing in freshness or maturity should be evaluated. There is no evidence that organic foods may be more susceptible to microbiological contamination than conventional foods. While it is likely that organically grown foods are lower in pesticide residues, there has been very little documentation of residue levels.     

“商机无限”的中国有机食品产业——访中国有机农业产业发展联盟主席杜相革先生

<正> 十年来,中国有机产业蓬勃发展的态势令世人瞩目,但快速发展的同时,也存在着产品单一、深加工产品缺乏、生产规模小、销售渠道窄等问题。如何让中国的有机产业逐渐成熟,走上健康发展的道路,既需要全行业的携手努力,也需要相关行业协会的指导与帮助。中国有机农业产业发展联盟(CFOAM)由中国农业大学有机农业技术研究中心发起,联合国内外多家有机产品生产和销售企业,充分利用政府机构、高等学院、有机生产企业、流通企业等多项资源,于2007年在香港注册成立。     

Evaluation of the micronutrient composition of plant foods produced by organic and conventional agricultural methods

The aim of the present analysis was to evaluate the micronutrient content of plant foods produced by organic and conventional agricultural methods. Studies were identified from a search of electronic databases (1980-2007, inclusive) as well as manual searches. A total of 66 studies (describing 1440 micronutrient comparisons) were identified. Thirty-three studies (908 comparisons) satisfied the screening criteria which considered cultivar, harvesting, and soil conditions. In studies that satisfied the screening criteria, the absolute levels of micronutrients were higher in organic foods more often than in conventional foods (462 vs 364 comparisons, P=0.002), and the total micronutrient content, expressed as a percent difference, was higher in organic (+5.7%, P<0.001) as compared to conventionally grown produce. The micronutrient content of food groups was more frequently reported to be higher for organic vegetables and legumes compared to their conventional counterparts (vegetables, 267 vs 197, P<0.001; legumes, 79 vs 46, P=0.004). This trend was supported by a mean percent difference in micronutrient content favoring organic vegetables (+5.9%, P<0.001) and legumes (+5.7%, P<0.001). Further research is required to determine the effect of organic agricultural methods on a broader range of nutrients and their potential impact on health.     

有机肥施用对烟田土壤细菌多态性的影响

为实现烟田土壤保育的目标,对长年连作的烟田施用有机肥,采用高通量测序技术,应用Solexa基因组分析平台,测定和分析复合有机肥OFN、OFJ和烟草秸秆有机肥TS对烟田土壤细菌多态性的影响。结果表明,相对于单施化肥,烟田施用有机肥后,烟田土壤细菌OTU、chao1指数和ace指数增大,表明有机肥提高了烟田土壤细菌物种丰富度;细菌丰富度因有机肥种类而不同,并随烟草发育期而产生差异。有机肥对土壤细菌菌群结构影响显著,在门和属的分类水平上,土壤优势细菌种类和比例产生明显改变,特别是有机肥处理可显著提高假丝酵母属细菌的丰度,而降低红色杆菌属、硝化螺旋菌属细菌的丰度。KEGG代谢途径差异分析发现,施用有机肥后土壤细菌代谢路径和代谢路径中基因数量发生改变,而改变了烟田土壤细菌群落功能和细菌代谢。总之,烟田施用有机肥改变了土壤细菌的多态性,并可能达到烟田土壤保育的效果。     

Nitrogen form affects yield and taste of tomatoes

Different nitrogen forms in organic or mineral fertilizers affect yield, quality and taste of tomatoes. Tomato plants were grown in a greenhouse for 10 weeks and fertilized with two different organic fertilizers (manure or grass and clover mulch) or with three different mineral nutrient solutions (NO₃^?:NH₄⁺) ratios 4:1 or 1:4). In an attempt to mimic the nutrient supply of the organic production systems, mineral fertilizers with ammonium as the dominating N‐source were combined with two chloride levels. Total nitrogen supply was 650 mg N plant^?1 week^?1 in all treatments. There was no difference in the yield of red tomatoes between the treatments (mean 1.95 kg FW plant^?1). However, the yield of green tomatoes at the final harvest was significantly higher in the mineral nutrient treatments (mean 1.37 kg FW plant^?1) compared with the organic treatments (mean 0.88 kg FW plant^?1). Plant biomass was higher for the mineral nutrient treatments (mean 1.05 kg FW plant^?1) compared with the organic treatments (0.89 kg and 0.72 kg FW plant^?1 in the manure and the grass and clover mulch treatments, respectively). Significantly higher scores were achieved for sweetness, acidity, flavour and acceptance for the tomatoes grown with the organic or the ammonium‐dominated treatments compared with the tomatoes grown with the nitrate dominated nutrient solution. It is suggested that ammonium is an equivalent nitrogen source for tomato plants compared with nitrate and that, when tomato plants are supplied with reduced nitrogen forms such as ammonium or organic nitrogen, an improved tomato fruit taste can be observed. Copyright © 2005 Society of Chemical Industry     

Effects of organic and conventional growth systems on the content of carotenoids in carrot roots, and on intake and plasma status of carotenoids in humans

BACKGROUND: The demand for organic food products has increased during the last decades due to their probable health effects, among others. A higher content of secondary metabolites such as carotenoids in organic food products has been claimed, though not documented, to contribute to increased health effects of organic foods. The aim was to study the impact of organic and conventional agricultural systems on the content of carotenoids in carrots and human diets. In addition, a human cross‐over study was performed, measuring the plasma status of carotenoids in humans consuming diets made from crops from these agricultural systems. RESULTS: The content of carotenoids in carrot roots and human diets was not significantly affected by the agricultural production system or year, despite differences in fertilisation strategy and levels. The plasma status of carotenoids increased significantly after consumption of the organic and conventional diets, but no systematic differences between the agricultural production systems were observed. CONCLUSION: The expected higher content of presumed health‐promoting carotenoids in organic food products was not documented in this study. Copyright © 2011 Society of Chemical Industry     

A review on tomato authenticity: quality control methods in conjunction with multivariate analysis (chemometrics)

Authenticity and traceability have been two of the most important issues in the food chain. Authenticity in particular, is closely related with both food quality and safety issues. Vegetables stand for a category of foods heavily affected by adulteration either in terms of geographic origin (national or international level) or production methods (organic or conventional production, fertilizers, pesticides, genetically modified vegetables). This review aims at addressing most of the currently applied methods for ensuring quality control of vegetables; a) instrumental: ion chromatography, high pressure liquid chromatography, atomic absorption spectrophotometry, electronic nose and mass spectroscopy and b) sensory analysis. The results of all the above mentioned methods were analyzed by means of multivariate analysis (principal component analysis, discriminant analysis, cluster analysis, canonical analysis, and factor analysis). All ensuing results and conclusions are summarized in eight comprehensive tables.     

Sustainable nitrogen fertilisation in sweet pepper: assessing growth and fruit quality and the potential nitrate pollution from different organic manures

BACKGROUND: The use of organic cultivation with manures does not avoid the risk of high nitrate concentrations if nutrient management is inefficient. So we studied the influence of three organic manures combined or not with additional chemical fertilisers on growth and yield of sweet pepper (Capsicum annuum L.), and on the soil and plant N concentrations. RESULTS: After 3 years of organic cultivation, poultry manure caused the highest soil pollution. The evolution of nitrate and organic matter in soil showed a pattern close to that of plant growth. The addition of mineral fertiliser increased vegetative growth and yield, and a cumulative season effect was observed. In treatments with no additional mineral fertiliser N translocation from leaves to fruits happened. A cumulative effect of seasons on fruit quality and a reduction near to 30% was observed in the first fruit quality category after 3 years. The fruit vitamin C content was reduced by increasing N fertilisation. CONCLUSION: The effects of organic fertiliser on soil and plant growth and yield depended on the type of manure used, its rate, and consecutive crop seasons. Horse manure gave the best combination of agricultural and environmental characteristics and could be used without additional fertigation. © 2012 Society of Chemical Industry     

几种具有代表性青田石的矿物学特征初探

对封门矿区七个不同品种的青田石("封门青""金玉冻""黄金耀""朱砂""水草""紫罗兰""三彩")样品进行X射线粉末衍射、红外光谱、激光诱导离解光谱仪等测试,对其主要矿物组成,矿物组合及颜色成因进行了分析探讨。结果显示,"封门青"和"金玉冻"均为成分较纯的叶蜡石,属于叶蜡石型青田石;"黄金耀"的矿物组合为伊利石+少量叶蜡石,属于伊利石型青田石;"朱砂"的矿物组合为叶蜡石+石英+赤铁矿+高岭石,属于叶蜡石型青田石;"紫罗兰"的主要矿物组成是叶蜡石,属于叶蜡石型青田石,其紫色花星成分可能为贫铁蓝线石;"三彩"的主要矿物组成为叶蜡石,但其三个不同颜色(灰色,土黄色,黄绿色)部分的矿物组合不同,石英的质量分数较高且结晶较好是"三彩"显颗粒感的主要原因。     

施钾和有机肥对甘蔗生长及土壤理化性状的影响

以粤糖66号为供试作物,通过设置氮磷肥(NP)(CK)、氮磷钾肥(NPK)、钾减量配施有机肥(NP80%K+OM)、氮磷钾配施有机肥(NPK+OM)4个处理的田间试验,研究了施钾和有机肥对甘蔗生长及蔗区砖红壤理化性状的影响。结果表明,与NP(CK)相比,施用钾肥和有机肥能增加甘蔗分蘖率、株高、茎径和有效茎数,显著提高甘蔗产量和品质。各施肥处理中以NPK+OM蔗茎产量、糖分和糖产量最高,分别为120.0 t/hm2、13.92%和16.3 t/hm2,比NPK处理分别增产11.1%、11.5%和22.6%;配施有机肥能改善土壤理化性状,甘蔗收获后,NP80%K+OM和NPK+OM处理耕层土壤pH、有机质含量和速效氮、磷、钾含量均显著高于NPK处理。NP80%K+OM处理农艺性状、产量和品质均与NPK+OM处理无显著差异。综上所述,在氮、磷养分等量投入条件下,配施钾肥、有机肥能促进甘蔗生长,提高产糖量,改善土壤理化性质;适当钾减量(80%常规钾肥推荐量)配施有机肥并未显著降低甘蔗产量和品质,可在当地甘蔗生产中推广应用。     

Willingness of Iranian young adults to eat organic foods: Application of the Health Belief Model

This study investigates the determinants of organic foods consumer behavior in Iran. This will further understanding of consumer decision-making regarding organically produced foods and help identify strategies for promoting their consumption. The focus of the study was to explore the influence of constructs of the Health Beliefs Model on willingness to use organic foods using a multistage, stratified random sample of young adults (n = 389) in a survey conducted in Iran. Structural equation modeling showed that perceived benefits, general health orientation regarding pesticides and organic foods, self-efficacy and perceived barriers are significant predictors of willingness regarding the use of organic foods. These variables can predict nearly 42% variance of young adults’ willingness to use organic food. The findings yield public policy and marketing recommendations for stimulating organic food consumption among young adults.     

Fate of pesticides in the arid subtropics, Botswana, Southern Africa

Despite a history of pesticide usage, few data exist on their concentrations in air and soil of Southern Africa. To add to the understanding of the processes controlling the fate of organic contaminants in arid regions, the levels, spatial trends, and seasonal variability of pesticides were studied in air and soil from Botswana. XAD resin-based passive air samplers (PAS) were deployed at 15 sites across the country from May 2006 to May 2007. Soil samples were collected from the vicinity of nine of the PAS sampling sites. In addition, 27 24-h high-volume air samples were collected in Maun, at the southeastern edge of the Okavango Delta, every two weeks for one year. Levels of pesticides in PAS were low, with α-endosulfan and lindane being most abundant. Concentrations in soils were extremely low and only soils with high organic carbon contained notable amounts of dieldrin and traces of other pesticides. In particular, air and soil from the Okavango Delta had very low levels even though the area had repeatedly been sprayed with DDT and endosulfan in the past. Air samples from Eastern Botswana, where the majority of the population lives, contained higher levels. Higher air concentrations of α-endosulfan occurred during summer and higher HCB levels occurred in winter. This seasonality was related with neither minor seasonal changes in temperature nor hydrological seasonal events such as the rainy season or the flooding of the Okavango Delta. Thus, the observed spatial and seasonal patterns are more likely related to pesticide usage pattern than to environmental factors or historical use. High temperature and low organic matter content limit the uptake capacity of most subtropical soils for pesticides. No evidence was found that sorption to dry mineral matter plays a major role. Arid soils in subtropical regions are therefore neither a major reservoir of organic contaminants nor do they constitute a significant long-term source of pesticides to the atmosphere.     

不同商品有机肥对烤烟根际土壤环境及烟叶质量的影响

为探讨不同商品有机肥的施用效果,通过大田试验,研究了商品有机肥对玉溪山地烟区烤烟根际土壤环境及烟叶质量的影响。试验结果表明,施用商品有机肥均可提高烤烟团棵期根际土壤有机质含量及碱解氮含量。SC有机肥在烤烟全生育期对根际土壤有机质含量影响更为显著;SCG有机肥对团棵期根际土壤碱解氮含量的影响更为显著,且在成熟期与对照水平相当,同时可显著提高成熟期根际土壤蔗糖酶活性;FH和YT有机肥可显著提高团棵期根际土壤脲酶活性和碱解氮含量,成熟期碱解氮含量也显著高于对照。烟叶质量方面,施用商品有机肥均可提高中部烟叶外观质量和感官质量,SC有机肥可显著改善中部烟叶总糖含量和两糖差,SCG和SC有机肥对中部烟叶香韵和香气量改善更为明显。本研究认为,施用商品有机肥对烤烟根际土壤养分、酶活性及烟叶质量等均有不同程度的改善效果,其中SCG和SC有机肥在改善土壤养分及烟叶香气方面效果更为明显。     

Comparison of neem or oregano with thiram on organic matter decomposition of a sand loam soil amended with compost,and on soil biological activity

BACKGROUND: Oregano essential oil and neem have been reported to be effective against soil‐borne pathogens and nematodes. The possibility of having an effect on soil properties was the aim of this investigation. Moreover, thiram, a common widely used chemical pesticide, was used for comparison. RESULTS: The effects of all three above‐mentioned substances were investigated during an incubation experiment, for 15 weeks. Crushed neem pellets were added at 1.0, 2.0 or 3.0 g per 50 g of soil. Oregano dry matter was applied at 0.2, 0.4 or 0.6 g per 50 g of soil. Finally, thiram was applied at 0.1, 0.2 and 0.3 g per 50 g of soil. The addition of neem resulted in a decrease in organic carbon mineralisation, higher than that of oregano, but not as prominently as thiram. The addition of neem resulted in an increase in the content of nitrate, organic P, bioavailable P, bioavailable K and bioavailable Mn. Oregano had a slight negative effect on organic matter biodegradation, but caused an increase of nutritional mineral elements. Microbe colonies in soil were increased by the addition of neem cake granules, whereas oregano and thiram treatments caused a decrease. The addition of thiram reduced nitrate and available Mn contents, but at the lowest dose increased organic P and available K. Thiram reduced prominently available Cu at the upper rates, but it increased these forms at the lowest rate, while available Zn content was increased in two lowest rates. CONCLUSION: The results of this study indicated that neem or oregano could be applied to the soil without any extremely negative effect on the available forms of nutritional mineral elements, as thiram does. Copyright © 2009 Society of Chemical Industry