Tuesday, March 23, 2010

Tasty spuds need not be organic

A group of Irish scientists have shown that there is no difference in taste between organically and conventionally grown potatoes.

In a study published in this month's edition of the International Journal of Food Science and Technology, Clare Hilsenan, Roisin Burke and Catherine Barry-Ryan from Dublin Institute of Technology, reported that a panel of consumer tasters could find no significant difference between organic and non-organic potatoes.

Organic potatoes (of the cultivar Orla) were grown near Navan, Co. Meath and were fertilised with composted manure rather than the synthetic fertiliser applied to the conventional potatoes (also grown in Navan). Since potato blight (caused by Phytophthora infestans) is a serious fungal pest of potatoes in Ireland, the conventionally grown spuds were sprayed with a liquid copper fungicide designed to control the fungus. Since such synthetic additives are not permitted in organic agriculture, the organic potatoes were treated with Burgundy (a mixture of copper sulphate and washing soda).

Despite Burgundy currently being permitted in organic agriculture (like the related Bordeaux mixture) there are some doubts about the impact repeated applications of a copper-based treatment has on the local environment to which it is applied. Copper sulphate is toxic to some fish and if it finds its way into water bodies, can cause significant problems. It has also been shown to cause problems for bees, sheep, chickens and especially earthworms who are crucial for proper soil health and therefore the success of an organic agricultural system.

However, the use of Burgundy is a side issue and the study in question deals with the eventual taste of the harvested potatoes.

The potatoes from both sources were taken to the laboratory and baked in the oven.The colour, texture and the dry matter content of the  potatoes were measured as well as the pH and the amount of sugar present in the samples.

"tasters were asked to assess flavour, texture and aroma"Then comes the fun bit. A group of ten tasters (trained to international standards!) were asked to assess the flavour, texture and aroma of the raw and cooked potatoes. This involved them sitting in specially constructed booths were the temperature and light was controlled to insure that they were influenced by outside interference. As well as that, the order in which the samples were tasted were randomised in order to ensure that each had an equal chance of being first or last.

As well as these specially trained tasters, a panel of 80 regular potato eaters was gathered from amongst the staff and students of DIT and asked to assess cooked potatoes under the headings colour, aroma, texture and taste.

"some chefs may not agree with us" - Roisin Burke, DITThe results of the taste-tests were analysed and make for interesting reading. The trained panel of tasters found the organic potatoes to be harder, and drier than the conventionals.In terms of colour, aroma and taste, no significant differences were found between organic and conventionally grown samples.

When the 'untrained' consumer panel reported, they again found no statistical differences in the appearance, aroma, texture and taste.

Since the price difference between organic and conventionally- grown fruit and vegetables is sometimes staggering, these results indicate that taste should not be a factor in our decision if we choose conventional over organic potatoes. An analysis by the Sunday Times showed that 1 kg of organic potatoes cost €2 in Tesco this week compared to €1.06 for 1 kg of conventional spuds.

Speaking to that newspaper, one of the authors Roisin Burke noted that "some chefs may not agree with us" and that "There are other reasons why people eat organic potatoes, such as the lack of pesticides, but we found no difference in taste.


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