Is More Work Needed In The Organic vs Conventional Nutrition Debate?

0.30 mg of zinc in 100 g of organic cabbage compared  to 0.25 mg in an  equal amount of conventional cabbage, both grown in the summer of 1986. - Nutritional Quality of Organic Versus Conventional

Fruits, Vegetables, and Grains 

Ascorbic and citric acids were higher in organic than conventional peaches, whereas α-tocopherol was increased in organic pears. - Modulation of Antioxidant Compounds in Organic vs Conventional Fruit 

Total polyphenols content was higher in conventional plums. Quercetin was higher in conventional plums, but myrecitin and kaempferol were higher in organic plums. - Nutrients and Antioxidant Molecules in Yellow Plums (Prunus domestica L.) from Conventional and Organic Productions:  A Comparative Study

When results were expressed as fresh matter, organic tomatoes had higher vitamin C, carotenoids, and polyphenol contents (except for chlorogenic acid) than conventional tomatoes. When results were expressed as dry matter, no significant difference was found for lycopene and naringenin. In tomato purees, no difference in carotenoid content was found between the two modes of culture, whereas the concentrations of vitamin C and polyphenols remained higher in purees made out of organic tomatoes. - Influence of Organic versus Conventional Agricultural Practice on the Antioxidant Microconstituent Content of Tomatoes and Derived Purees; Consequences on Antioxidant Plasma Status in Humans

Organic tomato fruits contained more dry matter, total and reducing sugars, vitamin C, total flavones and beta-carotene, but less lycopene in comparison to conventionally grown tomatoes. - Comparison of the Nutritive Quality of Tomato Fruits from Organic and Conventional Production in Poland

Organic fruits tend to have higher hydrolysable polyphenol contents than conventional ones, with values being 11.5% in orange peels, to 72.6% in papaya peels, higher for hydrolysable polyphenols. Fruit peels also showed higher concentration of polyphenols than pulp, reaching, for bananas and tangerines, twice the amount found in pulps, which reflected in higher antioxidant capacity. - Polyphenol content and antioxidant capacity in organic and conventional plant foods

Blueberry fruit grown from organic culture yielded significantly higher sugars (fructose and glucose), malic acid, total phenolics, total anthocyanins, and antioxidant activity (ORAC) than fruit from the conventional culture. Organic culture also produced fruit with higher contents of myriceti 3-arabinoside, quercetin 3-glucoside, delphinidin 3-galactoside, delphinidin 3-glucoside, delphinidin

3-arabinoside, petunidin 3-galactoside, petunidin 3-glucoside, and malvidin 3-arabinoside than

conventional culture. - Fruit Quality, Antioxidant Capacity, and Flavonoid Content of Organically and Conventionally Grown Blueberries

Overall, the results show that organic management and fertilization have a positive effect on the accumulation of certain beneficial minerals and phenolic compounds in eggplant and that organically and conventionally produced eggplants might be distinguished according to their composition profiles. - Effects of Organic and Conventional Cultivation Methods on Composition of Eggplant Fruits

Organic oranges had significantly higher total phenolics, total anthocyanins and ascorbic acid levels than the corresponding non–organic oranges (all p < 0.05). Moreover, the organic orange extracts had a higher total antioxidant activity than non–organic orange extracts (p < 0.05). In addition, our results indicate that red oranges have a strong capacity of inhibiting the production of conjugated diene containing lipids and free radicals in rat cardiomyocytes and differentiated Caco–2 cells, respectively. Statistically higher levels of antioxidant activity in both cell models were found in organically grown oranges as compared to those produced by integrated agriculture practice. Our results clearly show that organic red oranges have a higher phytochemical content (i. e., phenolics, anthocyanins and ascorbic acid), total antioxidant activity and bioactivity than integrated red oranges. Further studies are needed to confirm whether the organic agriculture practice is likely to increase the antioxidant activity of other varieties of fruits and vegetables. - Antioxidant effectiveness of organically and non-organically grown red oranges in cell culture systems 

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. - Evaluation of the Micronutrient Composition of Plant Foods Produced by Organic and Conventional Agricultural Methods



The two production systems resulted in different morphological attributes since organic kiwifruits exhibited a larger total and columella area, smaller flesh area, more spherical shape, and thicker skin compared to conventional kiwifruits. All the main mineral constituents were more concentrated in organic kiwifruits, which also had higher levels of ascorbic acid and total phenol content, resulting in a higher antioxidant activity. Sugars and organic acids composition was not affected by the production system. - A comparative study of composition and post harvest performance of organically and conventionally grown kiwifruits

In a study of five vegetables common in the Japanese diet, Ren et al. demonstrated that organically grown spinach contained 120 percent higher antioxidant activity while Welsh onion, Chinese cabbage and qing-gen-cai contained 20-50 percent  higher antioxidant activity compared to their conventionally grown counterparts. - Antioxidative and antimicrobial activities and flavonoid contents of organically cultivated vegetables

In our own studies, we have found consistently higher levels of total phenolics and ascorbic acid in organic strawberries, marionberries and sweet corn. - Comparison of the total phenolic and ascorbic acid content of freeze-dried and air-dried marionberry, strawberry, and corn grown using conventional, organic, and sustainable agricultural practices.

Results from the study showed inconsistent pattern with respect to vitamin C, calcium and potassium contents in the conventionally and organically grown samples. No significant differences were observed in vitamin C content in conventionally and organically grown cabbage, carrots and Cos lettuce while significant differences were observed in Valencia oranges which showed higher vitamin C content in organic Valencia oranges as compared to conventional ones (51.8 to 43.4 mg/100 g fresh weight). Results on calcium and potassium contents showed significant differences in all the samples with the trend of higher values for organically grown cabbage, carrots and Cos lettuce as opposed to their conventionally grown counterparts. However, for Valencia oranges, results showed that the calcium and potassium contents were significantly higher in conventional Valencia oranges compared to the organic Valencia orange (54.5 and 192.0 mg to 51.8 and 189.5 mg/100 g, respectively). - Determination and comparison of vitamin C, calcium and potassium in four selected conventionally and organically grown fruits and vegetables

Conventional Grapefruit was better colored and higher in lycopene, and the juice was less tart, lower in the bitter principle naringin, and better accepted by the consumer panel than the organic fruit. Organic fruit had a commercially preferred thinner peel, and the juice was higher in ascorbic acid and sugars and lower in nitrate and the drug interactive furanocoumarins. - Organic vs Conventionally Grown Rio Red Whole Grapefruit and Juice:  Comparison of Production Inputs, Market Quality, Consumer Acceptance, and Human Health-Bioactive Compounds

The results obtained showed that organic carrots contained significantly more dry matter, vitamin C, phenolic acids and carotenoids in comparison to the conventional ones. - The content of bioactive compounds in carrots from organic and conventional production in the context of health prevention

. Comparisons of analyses of archived samples from conventional and organic production systems demonstrated statistically higher levels (P < 0.05) of quercetin and kaempferol aglycones in organic tomatoes. Ten-year mean levels of quercetin and kaempferol in organic tomatoes [115.5 and 63.3 mg g-1 of dry matter (DM)] were 79 and 97% higher than those in conventional tomatoes (64.6 and 32.06 mg g-1 of DM), respectively. The levels of flavonoids increased over time in samples from organic treatments, whereas the levels of flavonoids did not vary significantly in conventional treatments. - Ten-Year Comparison of the Influence of Organic and Conventional Crop Management Practices on the Content of Flavonoids in Tomatoes

The results indicated lower nitrate content and higher vitamin C and chlorogenic acid content to be the parameters most consistently differentiating organically from conventionally produced potatoes. Elevated concentrations of glycoalkaloids were also observed throughout the experiments in some potato varieties grown in organic farming systems. Principal component analysis (PCA) of the analytical and other data using three PCs confirmed a good separation between the organically and conventionally produced potatoes when studied in single crop years. However, score-plots (objects) and loading-plots (variables) of pooled results from the consecutive harvests showed that between the years’ changes and also variety as well as geographical variations are equally or more important factors determining the quality of potatoes than the farming system. - Quality of organically and conventionally grown potatoes: Four-year study of micronutrients, metals, secondary metabolites, enzymic browning and organoleptic properties

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