The National Institute of Nutrition (NIN), Hyderabad, recently conducted a study on 14 fresh fruits and 120-130 foods so as to compile a database on the antioxidant activity on most commonly consumed foods in India.

The study was conducted on most commonly consumed fresh fruits in India such as guava, pine-apple, Indian plum, mango (ripe), apple, chiku, watermelon, custard apple, grapes (green), orange, papaya (ripe), pomegranate, sweet lime and banana.

"This was the first-of-its kind research carried and interestingly, out of 14 fresh fruits, we found that mango and guava were rich in antioxidants," Dr Sreeramulu, scientist, endocrinology and metabolism division, NIN, Hyderabad, informed FnB News in a telephonic talk.

Ramulu said that the data available on most commonly consumed foods and fresh fruits were scanty on antioxidant activity (AOA) that had also received less attention so far in the country, hence it was pertinent to determine the AOA in such foods.

He said that the findings were quite interesting as the research indicated that fruits which were rich sources of nutrition and that were rich in antioxidants helped scavenge the free radicals that destroy tissues.

In the study, guava came in at the top with antioxidant activity ranging from as high as 496 mg/100 gm to as low as 22 mg/100 gm in pineapple. He further said that antioxidants play a crucial role in preventing cellular damage which was the most common reason for ageing, cancer and other degenerative diseases.

Initially for the study, three samples of each variety of fresh fruit were purchased from each of the three local markets, pooled and considered as a single sample of that market. Total quantity of each pooled sample was 250-300 gm. Adequate care was then taken to avoid unripe, damaged and overripe fruits.

Fruits purchased from the market were cleaned and edible portions were cut into small pieces and extracted with acidified aqueous methanol. Briefly, edible portions of total sample were powdered in a domestic blender where fresh fruits were directly taken into polytron homogeniser and extracted. Extraction and analysis of antioxidant activity and total phenolic content was done separately in three market samples.
Ramulu mentioned that epidemiological studies suggest that increased consumption of fruits and vegetables was associated with a lower risk of degenerative diseases and that the current lifestyle caused overproduction of free radicals and reactive oxygen species.
Therefore, natural antioxidants protect from oxidative stress and associated diseases and play an important role in healthcare whereby, plant foods were the primary source of natural antioxidants. Fruits and vegetables are important dietary sources of antioxidant polyphenols to humans.

"As compared to fresh fruits, polyphenolic content and AOA of dryfruits are expected to be high due to their low moisture content with increased shelf life. In recent times, natural antioxidants have attracted considerable interest among nutritionists, food manufacturers and consumers because of their presumed safety and potential therapeutic value," he pointed out.