Greenhouse Canada

Sauna prolongs life of vegetables

August 24, 2009  By The Canadian Press

Aug. 24, 2009, Kentville, N.S. – Researchers in Kentville, N.S., have discovered that giving fruits and vegetables a sauna can extend their shelf life by 50 per cent.

Researchers in Kentville, N.S., have discovered that giving fruits and vegetables a sauna can extend their shelf life by 50 per cent.

Bob Stark and Katherine Sanford, who work at the Atlantic Food and Horticulture Research Centre, have devised a way to use spas to extend the shelf life of fruits and vegetables, while at the same time improving their flavour, colour and quality.


The work began a few years ago when the two researchers began experimenting with the spa process on fresh cabbage, followed by melons, blueberries and peppers.

The produce is put through a process called low-temperature thermal treatment, which bathes the fruits and vegetables in moist warm air before cooling them.

The steam process not only kills micro-organisms that shorten shelf life, but it also activates a chemical process that enhances the colour, flavour, quality and texture, Stark and Sanford said in a recent interview at the research centre.

"Being able to extend the shelf life while keeping the quality, colour, flavour and original texture of the product is important," said Sanford.

"The whole driving force on this project was the concept of getting people to increase their fruit and vegetable consumption.''

One of the things that prevent people from eating more fruits and vegetables is convenience. The research focused on improving convenience while keeping the nutritional content.

"We've had a very positive response to the products when we did consumer testing with them," Sanford said. "People liked the product. There's a slight enhancement of the sweetness, while keeping the texture."

The steam process can also be used to kill insects and was originally designed for organic products.

"So something that's mild and non-chemical can be used to clean up some products," said Stark. "It looks very promising for the organic aspect."

The low-temperature thermal machine was developed by the two researchers and found to be more effective than traditional methods used on fruits and vegetables, including blanching.

The longer shelf life and improvements in quality could translate into big savings for retailers and consumers.

Statistics Canada estimates that stores, restaurants and families throw out nearly half of their fruits and vegetables because of spoilage.

The machine, a prototype of which is at the research centre, can also act as a commercial cooker, especially for small potatoes.

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