Friday, October 1, 2010


Potato is not considered a good source of antioxidants but if efforts by a group of scientists in increasing the level of antioxidants bear fruit, probably it may enhance its value as a healthy food. Normally potato is a source of starch, providing a significant portion of food calories in diets of some populations. Besides it is also a good source of potassium and some minor nutrients. Industrially the snacks derived from potato are very popular world over while products like French fries, Tater tots are commonly consumed food items served in many fast food chain outlets in the western world. Besides starch preparations derived from potato have special properties as an industrial starch and are much sought after. Vitamin C, Polyphenols, Carotenoids, Anthocyanins etc present in potato provides the antioxidant activity, its ORAC value being 7.8-14.2. Subjecting potatoes to electrical stimulus has been found to increase its antioxidant value significantly.

The electrical treatment involved immersing the potatoes in a salt solution for 10 seconds and then applying a small electrical charge for 10, 20, and 30 minutes. Reseachers then measured both the antioxidant activity and the phenolic content. Both treatments increased signifantly the stressed potatoes' antioxidant content. For example, t he five minute ultrasound treatment increased polyphenol levels by 1.2 times and other antioxidants by about 1.6 times. Subsequent results revealed that antioxidant levels had rocketed by up to 60 per cent. "We knew from research done in the past that drought, bruising, and other stresses could stimulate the accumulation of beneficial phenolic compounds in fresh produce," said Hironaka who is with Obihiro University in Hokkaido, Japan. "We found that there hasn't been any research on the healthful effects of using mechanical processes to stress vegetables. So we decided in this study to evaluate effect of ultrasound and electric treatments on polyphenols and other antioxidants in potatoes." Growing consumer interest in healthy or functional foods could mean a bright future for the low cost and straight-forward treatment techniques.

Though the above findings are of some academic interest, pursuing this line of research may yet elevate the status of this humble tuber as a health boosting food. How far such a development will be of interest to the processing industry depends on many factors but at house hold level a high antioxidant activity potato can be a boon to those who consume potato regularly as the staple. Increased levels of poly phenols can pose problems to the processing industry because of the activity of the native poly phenol oxidase enzyme system which can tend to develop brown color during peeling and cutting process, marring the appearance of end products.


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