Juice from organically grown tomatoes contains higher levels of bioactive polyphenols than juice made from conventionally grown tomatoes, says a new study.
The study, published in Food Chemistry, adds to the ongoing debate about the nutritional content on organic fruit and vegetables, compared with conventionally grown varieties.
“Using principal component analysis, results show that phenolic compounds and hydrophilic antioxidant capacity were responsible for the differentiation between organic and conventional tomato juices,” wrote researchers from the University of Barcelona.
“Thus, there appear to be genuine differences in the bioactive components of organic and conventional tomato juices not previously reported.”
Organic vs conventional
The fundamental differences between organic and conventional agricultural systems are in fertilization strategy and soil fertility management, which in theory affect the nutrient composition in plants and provide healthier better tasting produce.
However, previous studies on the nutrient content of organically and conventionally grown plants have generated contradicting results.
In 2009 an FSA review on the nutritional content of organic and conventional produce sparked controversy after it concluded that there are no differences.
Research conducted at the London School of Hygiene and Tropical Medicine concluded that “there is no evidence to support the selection of organically produced foodstuffs to increase the intake of specific nutrients or nutritionally relevant substances.”
However, several smaller studies have since reported higher levels of certain nutrients in organically grown produce, including strawberries.
In addition, a French review completely contradicted the findings of the FSA concluding that “organic plant products contain more dry matter and minerals – such as iron and magnesium – and more antioxidant polyphenols like phenols and salicylic acid.”
The new study is in-line with the French review, with organic tomato juice containing significantly higher levels of phenolic compounds, such as ferulic acid, caffeic acid, chlorogenic acid, and dicaffeoylquinic acid.
The researchers’ rationalisation of the results points to the natural defence mechanisms of the plants: “When plants are grown with artificial nutrients, they are supposed to lose their natural defence mechanisms,” they state.
“This may result in reduced disease resistance and diluted contents of minerals, vitamins and defence-related secondary metabolites, which are considered beneficial for human health.”
“In the present study the growing conditions of tomatoes (conventional versus organic) affected the content of twelve phenolic compounds and the antioxidant capacity in tomato juices.”
Source: Food Chemistry
Volume 130, Issue 1, Pages 222-227
“Is there any difference between the phenolic content of organic and conventional tomato juices?”
Authors: A. Vallverdu-Queralt, A. Medina-Remon, I. Casals-Ribes, R.M. Lamuela-Raventos