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; 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.     

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.     

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.     

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     

Mechanisms for controlling enzymatic reactions in foods

Enzymes, as biocatalysts, are capable of specific manipulation of all the major biomolecules found in foods, and a wide variety of enzymes are therefore used as supplements for various food processing operations. There are, however, certain enzymes whose activities result in a rapid deterioration of food quality to be controlled in order to maintain quality and to extend product shelf‐life. Various mechanisms and techniques for controlling the undesirable activities of such enzymes in foods have been developed ingeniously over the years by food scientists. These include traditional methods like low‐ and high‐temperature treatment, chemical treatments, and control of water activity involving dehydration and salting. These techniques, however, have certain limitations, such as (1) changing the prime quality of certain foods, (2) health risks associated with certain chemical treatments, and (3) consumer preference for certain foods to be raw and “natural”. Novel and potentially viable techniques such as pressurization, use of enzymes (“killer enzymes”), ionizing radiation, chemical modification of enzymes, and other naturally occurring protein inhibitors have therefore been developed to help alleviate some of these problems.     

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.     

Determination of chemical hazards in foods using surface-enhanced Raman spectroscopy coupled with advanced separation techniques

BackgroundSurface-enhanced Raman spectroscopy (SERS) has been validated as a highly accurate and specific technique for the discrimination, identification, and potential quantification of different types of chemical compounds. However, its application for the detection of potential hazardous chemical targets in foods has not yet been well developed due to interferences from the complicated food matrices, which could lead to challenges in spectral deconvolution and interpretation. The accurate separation and enrichment of the analyte from food samples are major challenges for analytical chemists and food technologists.Scope and approachFour promising “capturing” techniques (molecularly imprinted polymers, aptamer, antibody, and microfluidics) coupled with SERS were introduced in this review paper for the reliable and ultrafast determination of chemical hazards in food systems. These developed “one-step” or “two-step” SERS methods can achieve accurate and sensitive detection of trace level chemical hazards in agricultural products including foods.Key findings and conclusionsTandem SERS methods can be applied for rapid and reliable detection of trace level of chemical hazards in foods.     

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.     

Food system orientation and quality perception among consumers and producers of organic food in Hedmark County,Norway

To explore the potentials of organic agriculture, it is important to know how consumers, as well as producers, relate to food quality and food system issues. A consumer survey from the Hamar region in Southern Norway provided information on a number of these issues, and a rapid food system appraisal and a seminar revealed concerns among organic farmers in the region. Multivariate analyses showed that traditional food quality aspects such as freshness and taste, called “observation traits,” were important to all consumers. In addition, those who purchased organic foods were more concerned about ethical, environmental, and health issues, called “reflection traits”. Three consumer orientations in the food market were identified. Consumers with a “practical” orientation were less likely, and those with a “local” orientation in the food market were more likely, to buy organic food, while “social” considerations were equally important to all. The results indicate that many interests of organic farmers coincide with concerns among those who buy organic food, and that these are more complex than the formal rules for organic agriculture. This may provide a basis for identifying common goals and improving communication and cooperation between consumers and producers in order to further develop the organic food system. [Note that organic agriculture is called “ecological agriculture” in the Nordic Region.]     

Co-existence of GM,conventional and organic crops in developing countries: Main debates and concerns

ABSTRACT

The co-existence approach of GM crops with conventional agriculture and organic farming as a feasible agricultural farming system has recently been placed in the center of hot debates at the EU-level and become a source of anxiety in developing countries. The main promises of this approach is to ensure “food security” and “food safety” on the one hand, and to avoid the adventitious presence of GM crops in conventional and organic farming on the other, as well as to present concerns in many debates on implementing the approach in developing countries. Here, we discuss the main debates on (“what,” “why,” “who,” “where,” “which,” and “how”) applying this approach in developing countries and review the main considerations and tradeoffs in this regard. The paper concludes that a peaceful co-existence between GM, conventional, and organic farming is not easy but is still possible. The goal should be to implement rules that are well-established proportionately, efficiently and cost-effectively, using crop-case, farming system-based and should be biodiversity-focused ending up with “codes of good agricultural practice” for co-existence.     

THE SENSITIVITY OF DIFFERENT BREWING YEAST STRAINS TO CARBON DIOXIDE INHIBITION: FERMENTATION AND PRODUCTION OF FLAVOUR-ACTIVE VOLATILE COMPOUNDS

The sensitivity of brewing yeast strains, with different oxygen demands, to carbon dioxide inhibition was investigated. Laboratory fermentations were performed with, and without, protein-based “yeast foods” to lower dissolved CO₂ during fermentation. Differences were observed in yeast fermentative performance in the presence and absence of “yeast foods” for all yeast strains tested. Fermentation performance was improved with the addition of “yeast foods”. There was improved carbohydrate utilisation and amino acid uptake, while acetaldehyde levels at the end of fermentation were decreased. There was an increase in fusel oil production and acetate ester levels at the end of fermentation. Sulphur dioxide levels at the end of fermentation were unaffected by “yeast food” addition. Different yeast strains displayed differing sensitivity to CO₂ inhibition for all parameters tested. Sensitivity to CO₂ was not found to be related to oxygen demand of the yeast strains.     

Consumer understanding of sustainability concept in agricultural products

The term “sustainability” is based on three main pillars: environment, society and economy. To achieve sustainable development, agriculture is one of the main fields to be considered and it is key to address economic, environmental and ethical problems. Besides, consumers are increasingly demanding foods produced under sustainable practices and aiming to get involved in the process of enhancing food sustainability. Under such premises, a study was carried out with more than 3600 consumers in 6 countries (Brazil, China, India, Mexico, Spain and USA). Participants were asked questions organized in two main topics: general sustainability and willingness to pay on different food categories. In general, results showed that consumers thought that a sustainable product is “environmentally friendly”, “healthier”, has been grown using “few chemicals” and “have better quality”. More than 30% of consumers in the US and Spain were not willing to pay more for sustainable products. This percentage decreased to 20% in China, Mexico and Brazil and reached the lowest value in India (~14%). The main conclusion is that consumers are not fully aware of the importance of sustainability; in general, consumers tend to associate sustainable production with just organic farming and higher quality.     

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.     

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     

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.     

Organic Food: Buying More Safety or Just Peace of Mind? A Critical Review of the Literature

Consumer concern over the quality and safety of conventional food has intensified in recent years, and primarily drives the increasing demand for organically grown food, which is perceived as healthier and safer. Relevant scientific evidence, however, is scarce, while anecdotal reports abound. Although there is an urgent need for information related to health benefits and/or hazards of food products of both origins, generalized conclusions remain tentative in the absence of adequate comparative data. Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives; yet, the significance of this difference is questionable, inasmuch as actual levels of contamination in both types of food are generally well below acceptable limits. Also, some leafy, root, and tuber organic vegetables appear to have lower nitrate content compared with conventional ones, but whether or not dietary nitrate indeed constitutes a threat to human health is a matter of debate. On the other hand, no differences can be identified for environmental contaminants (e.g. cadmium and other heavy metals), which are likely to be present in food from both origins. With respect to other food hazards, such as endogenous plant toxins, biological pesticides and pathogenic microorganisms, available evidence is extremely limited preventing generalized statements. Also, results for mycotoxin contamination in cereal crops are variable and inconclusive; hence, no clear picture emerges. It is difficult, therefore, to weigh the risks, but what should be made clear is that 'organic' does not automatically equal 'safe.' Additional studies in this area of research are warranted. At our present state of knowledge, other factors rather than safety aspects seem to speak in favor of organic food.     

Organic Agriculture and Undernourishment in Developing Countries: Main Potentials and Challenges

While much has been published on the advantages of organic agriculture, less has addressed its potentials and challenges to fight undernourishment in developing countries. This article aims at reviewing the main potentials and challenges of this approach when dealing with “undernourishment” as a multifaceted concept in developing countries. Accordingly, 2 main issues of the concept which are “food security” and “food safety” are discussed in the context of both developed and developing countries to understand their different food policies’ priorities. Next, the main potentials, challenges and tradeoffs of the organic approach are analyzed to understand whether the approach is capable to provide a secure or a safe food-production system which can meet the food policy priorities in developing countries. With respect to food security, the article concludes that conventional and biotechnological approaches still produce higher yields than organic agriculture. However, considering the many advantages of organic agriculture, it can in a long run, be more conducive than now to meet food security. Thus, conventional approaches to feed the hungers in developing countries. Accordingly, the article emphasizes on the importance of providing farmers in developing countries with the possibility of implementing different approaches. Therefore, policy makers should be aware of a realistic and gradual transition from the other approaches to the organic that should be projected only in “long run,” and after conducting a series of risk assessment studies on the bases of both “crop-case” and “region-case.”     

Controlling organic chemical hazards in food manufacturing: a hazard analysis critical control points (HACCP) approach

Hazard analysis by critical control points (HACCP) is a systematic approach to the identification, assessment and control of hazards. Effective HACCP requires the consideration of all hazards, i.e., chemical, microbiological and physical. However, to-date most 'in-place' HACCP procedures have tended to focus on the control of microbiological and physical food hazards. In general, the chemical component of HACCP procedures is either ignored or limited to applied chemicals, e.g., food additives and pesticides. In this paper we discuss the application of HACCP to a broader range of chemical hazards, using organic chemical contaminants as examples, and the problems that are likely to arise in the food manufacturing sector. Chemical HACCP procedures are likely to result in many of the advantages previously identified for microbiological HACCP procedures: more effective, efficient and economical than conventional end-point-testing methods. However, the high costs of analytical monitoring of chemical contaminants and a limited understanding of formulation and process optimisation as means of controlling chemical contamination of foods are likely to prevent chemical HACCP becoming as effective as microbiological HACCP.     

INFLUENCE OF SOIL NUTRIENT LEVELS ON HARVEST YIELD AND MALTING QUALITY OF BREWING BARLEY

Four levels of N, P and K nutrition (poor, moderate, satisfactory and high) and all their possible combinations with 64 treatments in two replications (128 plots) were studied in a long term field trial on barley yield and malting quality. A standard East-European spring barley “Opal” (bred in Czechoslovakia) was grown in 1986, 13th year of the agricultural experiment, involving various crops in previous years, on a calcareous loamy chernozem soil. The optimum fertility levels for yield enhancement resulted in the poorest malting quality: low modification and extract but long saccharification time and high protein. To solve this problem the brewing industry will have to apply the well-known technological methods available since growers are not likely to give up their fertilizers. Applying soil and plant analysis data, having knowledge about both soil and plant optimum values, the danger of the excessive use of fertilizers can be realized and decreased.     

Does organic farming reduce the content of Cd and certain other trace metals in plant foods? A pilot study

The effect of organic cultivation systems on the level of Cd in wheat was studied in two consecutive harvests. Additionally, the concentrations of Cd, Pb, Cr and Zn were analysed in single harvests of rye, carrots and potatoes from different farming systems. Wheat and rye were obtained from controlled field trials using several conventional and ecological systems at two separate locations in Sweden. Potatoes and carrots were collected at private farms with conventional or ecological production. These farms were juxtapositioned and had similar soil properties. The levels of Cd in the wheat did not correlate with the cultivation system or the Cd content in the soil. Conventionally grown wheat from one field trial showed a significantly higher Cd level compared with ecologically grown wheat, while in the other field trial significantly lower Cd levels were detected in the conventionally grown wheat. No statistically significant differences in the concentrations of Cd, Pb, Cr or Zn in rye, carrots and potatoes were detected between the cultivation systems. The results indicate that organic farming, at least in the short term, does not necessarily result in reduced levels of Cd and other potentially harmful metals in foods of vegetable origin. Factors other than cultivation system may be of greater importance for the final concentration of Cd and other metals in plant foods. © 2000 Society of Chemical Industry