Organic Kiwi More Nutritious Than Conventional

Researchers from the University of Californiaboth the Davis campus and the schools Cooperative Extension in Yubaand the University of Foggia, Foggia, Italy have shown that, among other differences, organically kiwifruit had higher concentrations of vitamins and minerals than conventional fruit grown on the same farm. The results of this study were published yesterday in the online version of the Journal of the Science of Food and Agriculture in advance of the print version.

The researchers analyzed the post-harvest performance of organic and conventional Hayward kiwifruits grown on the same farm in Marysville, CA. The fruit were harvested at the same maturity stage. In addition to other analyses of the comparative quality of the fruit, the researchers determined the levels of minerals, sugars and organic acids, ascorbic acid, total phenolics, and antioxidants at 0, 35, 72, 90 and 120 days of storage at 0°C, and again after 1 week of shelf-life simulation at 20°C.

Results showed that organically and conventionally grown kiwifruits had similar soluble-solids content at the point of harvest, but conventional kiwifruits had a higher firmness and a lighter-green color when compared with the organic kiwifruits. These differences were maintained throughout all evaluated storage durations, although the soluble-solids content increased to a higher degree in conventionally grown kiwifruits during storage. Other general differences between the two samples were noted, including a smaller flesh area, more-spherical shape and thicker skin for the organic vs. conventional kiwifruit.

The vitamin and mineral content also differed between the two samples. The researchers note, 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. The sugars and organic-acids composition in the organic and conventional kiwifruit did not differ.