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.

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

Growing interest in organic agriculture has prompted numerous studies that compare various aspects of organic and conventionally produced foods. This paper provides a comprehensive evaluation of empirical studies comparing organic products and conventionally grown alternatives. The emphasis is on key organic consumer demand and marketing issues, including: (1) the implications of an economic definition of organically grown food for consumer demand; (2) attributes that shoppers consider most when comparing organic with conventionally grown products; (3) level and characteristics of consumer knowledge and awareness about organic food; (4) assessment methods and characteristics of organic consumer attitudes and preferences; (5) size of price premium and characteristics of consumers’ willingness-to-pay for organic products; and (6) profile of organic consumers. Overall, although there is some knowledge and awareness about organic products, consumers are not consistent in their interpretation of what is organic. Secondly, while consumers typically understand the broad issues about organic foods, many tend not to understand the complexities and niceties of organic farming practices and organic food quality attributes. Uncertainty regarding the true attributes of organic, and skepticism about organic labels, part of which stems from reported cases of (inadvertent) mislabeling, and product misrepresentation, and partly because of nonuniform organic standards and certification procedures, may hold some consumers back from purchasing organic. Thirdly, concern for human health and safety, which is a key factor that influences consumer preference for organic food, is consistent with observed deterioration in human health over time and, therefore, motivates consumers to buy organic food as insurance and/or investment in health. Fourthly, the proportion of consumers who are willing to pay a price premium for organic food decreases with premium level. On the other hand, premiums tend to increase with (combinations of) preferred attributes. In addition, demand tends to depend more on the price differential with respect to conventionally grown products, than on actual price. In contrast to sensitivity of demand to changes in price, income elasticity of demand for organic foods is generally small. Finally, it is important for policy analysts and researchers to note that organic fresh fruits and vegetables currently dominate the organic consumer's food basket. Furthermore, it is not clear whether frequent buyers consider particular organic products (e.g., organic meat) as normal goods, or if consumers consider such products as luxury goods.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1742170505000220

Comparison of consumer perceptions and preference toward organic versus conventionally produced foods: A review and update of the literature

Objectives: To survey existing literature comparing nutrient content of organic and conventional crops using statistical methods to identify significant differences and trends in the data. Design: Published comparative measurements of organic and conventional nutrient content were entered into a database for calculation. For each organic-to-conventional comparison, a percent difference was calculated: (organic-conventional)/conventional × 100. For nutrients where there was adequate data, the Wilcoxon signed-rank test was used to identify significant differences in nutrient content as represented by the percent difference. Mean percent difference values were also calculated for each significant nutrient by study and by vegetable for the most frequently studied vegetables. The nutrient content of the daily vegetable intake was calculated for both an organic and conventional diet. Results: Organic crops contained significantly more vitamin C, iron, magnesium, and phosphorus and significantly less nitrates th...

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Nutritional quality of organic versus conventional fruits, vegetables, and grains.

Cultural methods such as crop fertilization can affect susceptibility of plants to insect pests by altering plant tissue nutrient levels. Research shows that the ability of a crop plant to resist or tolerate insect pests and diseases is tied to optimal physical, chemical and mainly biological properties of soils. Soils with high organic matter and active soil biology generally exhibit good soil fertility. Crops grown in such soils generally exhibit lower abundance of several insect herbivores, reductions that may be attributed to a lower nitrogen content in organically farmed crops. On the other hand, farming practices, such as excessive use of inorganic fertilizers, can cause nutrient imbalances and lower pest resistance. More studies comparing pest populations on plants treated with synthetic versus organic fertilizers are needed. Understanding the underlying effects of why organic fertilization appears to improve plant health may lead us to new and better integrated pest management and integrated soil fertility management designs. © 2003 Elsevier Science B.V. All rights reserved.

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Soil fertility management and insect pests: harmonizing soil and plant health in agroecosystems

Food security, nutritional quality and safety vary widely around the world. Reaching these three goals is one of the major challenges for the near future. Up to now, industrialized production methods have clearly shown severe limitations such as a worldwide contamination of the food chain and water by persistent pesticide residues, and reduced nutrient and flavor contents through low-cost intensive food production and/or processing. In line with several published literature reviews, the French Agency for Food Safety (AFSSA) performed under my coordination an up-to-date exhaustive and critical evaluation of the nutritional and sanitary quality of organic food. This review is based on the AFSSA report issued and recently published studies. The major points are: 1/ organic plant products contain more dry matter and minerals (Fe, Mg); and contain more anti-oxidant micronutrients such as phenols and salicylic acid, 2/ organic animal products contain more polyunsaturated fatty acids, 3/ data on carbohydrate, protein and vitamin levels are insufficiently documented, 4/ 94–100% of organic food does not contain any pesticide residues, 5/ organic vegetables contain far less nitrates, about 50% less; and 6/ organic cereals contain overall similar levels of mycotoxins as conventional ones. Thus, organic agricultural systems have already proved able to produce food with high quality standards. I propose also improvements of organic production to achieve sustainable food production for humans in the near future.

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Nutritional quality and safety of organic food. A review

Worldwide attention in agricultural and in nutritional science is diverted to the controversy concerning ‘Quality’ versus ‘Quantity’ in connection with the alternatives of ‘Organic Manuring’ or ‘Chemical Fertilizing’ in relation to nutritional values in crops and their significance to human health. Some contribution towards classification of these problems is presented by the statistically significant results of our 12 years' experiment on two soils, fen and sand, including different organic manures and chemical fertilizers, namely 1) ‘Stable Manure’, 2) ‘Biodynamic Compost’, 3) ‘Stable Manure + NPK’, and 4) ‘NPK’. The difficulties in getting enough organic manures have no bearing on the subject of these investigations. The same is true for any considerations of economics. It could be shown by the aid of tables and annotated graphs that organic farming with 1) and 2) gave rise to considerable decreases in yield of 20 to 46% on fen, and of 28 to 56% on sand, in 8 crops grown in rotation or in succession within a year (2 crops/year). The losses in yield have been calculated in relation to means of yields given by 4)=100. These losses in yield the organic farmer must bear at his own expense, unless the nutritive value of his organically grown crops would rise to such an extent that low yield would be financially compensated by a higher price for his crops. That the consumer would benefit by a higher biological value of such products of 1) and 2) is beyond question, as confirmed by the following data based on 12 years' chemical investigations. Crops (both on fen and sand) manured with 1) and 2) have in comparison with 4)=100 contents on average higher. On the other hand detrimental and/or undesired constituents in crops show — due to organic manuring with 1) and 2) — average contents diminished in
 Finally let me comment upon the analytical results on behalf of the consumer in a somewhat practical way. Vegetables including potatoes are generally heated, by cooking in the household and restaurants or by blanching in processing plants. Their water-soluble constituents, minerals and trace elements, are not at all affected by a careful heating as usual, but on the other hand soluble vitamins of the B-complex and Vitamin C are affected but only to a certain extent. However, all these water-soluble plants constituents are strongly diminished in the food as eaten, if the cooking or the blanching water gets lost by pouring off. No doubt, using ‘hot pot’ diets (‘right across the kitchen garden’) losses from vegetables and potatoes in minerals and trace elements are entirely eliminated and those in water-soluble vitamins are only limited to destruction by heating. Therefore it may be concluded, that solely those diets including the cooking water or steam blanched products will justify the greater expense of a product richer in nutrients. Otherwise it would be rather illusive to claim for low yielding organically grown crops of high nutritional value, when the latter is carelessly wasted by foulty preparation ((3, pages 174–182; 187), 16, 17, 18, 20).

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Nutritional value of crops as influenced by organic and inorganic fertilizer treatments

Die als eiweisreich geltende Indianerkartoffel,Solanum stenotomumJuz. etBuk. wurde 1955 nach Anbau auf unseren Versuchsfeldern in Geisenheim u.a. auf ihren Eiweishaushalt untersucht. Langjahrige Mittelwerte) unserer Analysen von Kulturkartoffeln (258–260 Untersuchungen) dienten als Bezug, nachdem wir sie durch Berechnung der Schwankungsbreite von ±σ (68,3% aller Analysen) einem Vergleich zuganglich gemacht hatten.

Studien über essentielle Aminosäuren In Kartoffeln

The influence of inorganic and organic manures on the market quality and on the nutritional value of food plants is subject of this publication. Nutritional experiments with infants who were fed with vegetables of different fertilizer treatments gave significant results as follows:

Effects of the application of inorganic and organic manures on the market quality and on the biological value of agricultural products

1.

Atherisches Ol findet sich in der Speicherwurzel der Mohre in langgestreckten Exkretschlauchen der Rinde und der Seitenwurzelanlagen, bei der Wildmohre auserdem in Tropfchen unmittelbar unter dem Periderm.




2.

Ein ziemlich eindeutiger Unterschied scheint hinsichtlich Menge und Qualitat des atherischen Ols zwischen den Mohrensorten „Nantaise” (Anbau Geisenheim/Rh.) und „Bauers Kieler Rote” (Anbau Schleswig-Holstein) zu bestehen. „Bauers Kieler Rote” besas z.B. hohere Gehalte an atherischem Ol, das auch dunnflussiger war als das der Nantaiser Mohre.




3.

Folgende Beobachtungen an diesen beiden Sorten erfordern Beachtung: Als Insekticide genutzte chlorierte Kohlenwasserstoffe werden sortenverschieden in der Speicherwurzel deponiert („Nantaise”: in den auseren Zellschichten der Rinde; „Bauers Kieler Rote”: gleichmasig uber den Wurzelkorper verteilt). Die mogliche Rolle des atherischen Mohrenols (oder spezifischer Bestandteile) als Vehikel fur chlorierte Kohlenwasserstoffe wurde erwogen.

Fur diese Ansicht spricht:

Aldrin (weniger Dieldrin) ist in Dipenten leicht loslich. Aktives Dipenten, das 1-Limonen, ist ein Bestandteil des atherischen Mohrenols. Die Annahme war daher berechtigt, das Aldrin auch im atherischen Mohrenol loslich ist, was von uns experimentell bestatigt wurde. Die Loslichkeit war dabei im atherischen Ol der Sorte „Bauers Kieler Rote” groser als im atherischen Ol der Nantaiser Mohre.

Weitere Untersuchungen sind zur Verifizierung der bisherigen Befunde notwendig.

Histologisch-chemische Untersuchungen in Speicherwurzeln der Möhre (Daucus carota L.) in Beziehung zu Rückständen nach Aldrin- und Dieldrin-Behandlung

Beim Feldsalat und beim Spinat wurden mit steigenden N-Gaben unter den gegebenen Bedingungen sowohl in Klimakammer-Versuchen in Mitscherlichgefasen (Glassand + 1 % Torfmull), als auch in 10 m2 grosen Betonkasten-Parzellen auf N-bedurftigem Geisenheimer sandigen Lehmboden folgende Ergebnisse erzielt: 1. An Feldsalat (Valerianella olitoria L.), der in einer Klimakammer mit 2 Lichtstufen kultiviert wurde, konnte am Ertragsverlauf gezeigt werden, das die N-Wirkung mit hoherer Lichtintensitat steigt. Rohprotein- und Reineiweisgehalte des Feldsalates liesen bei den Versuchen mit steigenden Stickstoffgaben einen charakteristischen, flach S-formig ansteigenden Kurvenverlauf sowie einen absinkenden Relativen Eiweisgehalt (Eiweis-N in % Gesamt-N) und einen steilen Abfall der Eiweisqualitat (EAS-Indices nach B. L.Oser) erkennen. Fast alle essentiellen Aminosauren wiesen mit steigenden N-Gaben und bei hoherer Lichtintensitat einen ansteigenden Kurvenverlauf auf. Die Werte fur Histidin und Tryptophan veranderten sich dagegen kaum. Als einzige essentielle Aminosaure fiel Methionin mit steigenden N-Gaben bis zum Erreichen des Hochstertrages ab. Bei hoherer Lichtintensitat erhohten sich die Werte der EAS-Indices und die Methioningehalte deutlich gegenuber den entsprechenden bei geringerer Lichtintensitat. Analoge Befunde beim Kopfschlus (Kohlkopf, Kopfsalat) gegenuber freier Blattentfaltung werden diskutiert. 2. Im wesentlichen wurden diese Ergebnisse durch Freilandversuche an Spinat (Spinacia oleracea L.) mit steigenden N-Gaben (Kalkammonsalpeter) bestatigt. Wurde jedoch der Spinat in jungem, noch nicht voll entwickeltem Zustand geerntet, beobachteten wir ein Absinken der Methioningehalte und der EAS-Indices erst bei hohen N-Gaben (180 kg N/ha). 3. Der Methionin-Stoffwechsel in Pflanzen wird unter Berucksichtigung unseres heutigen Wissens und vorliegender Ergebnisse diskutiert.

Werner Schuphan

Papers

Nutritional value of crops as influenced by organic and inorganic fertilizer treatments

Studien über essentielle Aminosäuren In Kartoffeln

Effects of the application of inorganic and organic manures on the market quality and on the biological value of agricultural products

Histologisch-chemische Untersuchungen in Speicherwurzeln der Möhre (Daucus carota L.) in Beziehung zu Rückständen nach Aldrin- und Dieldrin-Behandlung

Methioningehalt und Eiweißqualität von Blattpflanzen in Abhängigkeit von der Stickstoffdüngung