12 January - 20 June 2016

Organic tomatoes found to contain more vitamin C

6 March 13

A study from the Federal University of Ceara in Brazil, published in the journal PLOS ONE has added to the debate on whether organic food is more nutritious than conventionally grown food.  A study published last year and cited in Food e-News found no difference between conventional and organic fruit and vegetables.  This current study by Miranda et al. investigated the hypothesis that tomato fruits from organic farming accumulate more nutritional compounds, such as phenolics and vitamin C as a consequence of the stressing conditions associated with farming systems.  The authors note that previous reviews of studies have indicated that environmental factors can influence the concentrations of phytochemicals.  Miranda et al. compared organic and conventionally grown tomatoes from two farms in Brazil which were within 1.5km from each other and therefore had similar environmental conditions.   They evaluated the tomatoes at three development stages, namely immature (green coloured), physiologically mature (breaker) and at the harvesting stage (red).  The team compared the concentrations in compounds contributing to quality including size, and also indicators of oxidative stress including activity of phenylanine ammonia lyase and cell membrane lipid peroxidation degree in the  organic and conventionally grown tomatoes.    Miranda et al. report that whilst growth in the organic fruit was 40% smaller than conventionally grown tomatoes, concentrations in vitamin C were respectively higher +29%, +57% and +55% at the stage of commercial maturity. Total phenolic content was also +139% higher than in the fruits from conventional farming and levels of sugars, and pigment like molecules like lycopene were also higher.  The organic tomatoes were found to accumulate more compounds linked to stress resistance, with cell membrane lipid peroxidation degree 60% higher in organic tomatoes.  Activity of phenylalanine ammonia lyase was also found to be two times higher in the organic fruit. The researchers indicate that tomato fruits from organic farming experience stressing conditions that result in oxidative stress and higher concentrations of soluble sugars, and other compounds contributing to the fruits nutritional quality.

RSSL's Functional Ingredients Laboratory provides vitamin analysis in a wide range of matrices including drinks, fortified foods, pre-mixes and multi-vitamin tablets.  It provides a full vitamin and mineral analysis service to assist with labelling, due diligence, claim substantiation and stability. For more information please contact Customer Services on Freephone 0800 243482 or email enquiries@rssl.com

RSSL's Functional Ingredients Laboratory can quantify lycopene in tomato-based products. For more information please contact Customer Services on Freephone 0800 243482 or email enquiries@rssl.com

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