Oxygen treatment found to extend shelf life

A week long pre-treatment of organic produce with low levels of oxygen can extend shelf life dramatically, according to new research.

The technique could replace current methods, allowing processors to maintain the quality of the organic produce supplies over a longer period.

The technique could also help reduce losses eventually helping to cut the high cost of organic fruit and vegetables supplies.

Edna Pesis and a team at the Volcani Centre in Israel found that by sealing Granny Smith apples in a low-oxygen atmosphere for seven days at 20C prior to cold storage reduced superficial scald development.

Pesis said that 90 per cent of the treated apples were "saved from the scald problem in addition to other physiological diseases" after eight months of cold storage.

All of the untreated apples were lost after eight months under the same conditions.

Scalding refers to a type of chilling injury associated with prolonged cold storage.

The technique can be tweaked for use with avocados, tomatoes and other organic produce, Pesis stated.

The research was published in the Journal of the Science of Food and Agriculture and reported on in Chemistry & Industry.

Both magazines are produced by the Society of Chemical Industry.

Currently UK shoppers pay twice as much for some organic products, according to research by Lisa Richards, reporting in Chemistry & Industry.

Organic apples, for example, are around double the price of conventionally grown apples in Sainbury's, Waitrose and Tesco, she found..

"One of the major contributing factors affecting the price is the short shelf life of organic produce," Richards said.

"Conventional produce can be treated with inexpensive chemicals to aid preservation.

But these cannot be used for organic produce, as by definition no artificial chemicals are used during processing."

Over the years, the industry has developed many methods to prevent superficial scald development in apples.

The most commonly used is treatment with a solution of the antioxidant diphenylamine (DPA).

However, there is some consumer resistance to DPA treated fruits, and non-chemical methods are needed, Richards reported.

Many organic farms have reasonably sophisticated refrigeration units, but these are very expensive and used only for brief storage before collection.

Although price is an issue, organic produce is becoming more and more attractive to the consumer because of increasing evidence that it may be the healthier option, she claimed.

Recent studies published by the association's journals found evidence that organic peppers had 33 per cent higher levels of vitamin C and 26 per cent higher phenolic compounds than peppers grown using modern farming methods.

Organic foods are one of the highest growing segments in the industry.

European consumers are spending up to €15bn on organic food per year, and demand is growing by up to ten per cent annually, according to the EU-funded European Information System for Organic Markets (EISfOM) project.

In the US sales of organic produce, cereals, snacks, soups, dairy and packaged meat have been growing by about 30 per cent a year said analyst ACNielsen.