Investigation on the Cause (s) of Tomato Fruit Discoloration and Damage under Chilling Condition Using External Antioxidants and Hot Water Treatment

The color of tomato fruit turns to red from green during ripening. The accumulated lycopene content of red tomato fruits is reduced when the fruits stored in the refrigerator. Therefore, this study was conducted in order to investigate the reason why red color tomato turns to light red when the fruit is stored at chilling temperature. A tomato variety (cv Rotarno) grown under greenhouse condition and harvested at red stage was used to assess color and firmness. Before storage at these temperatures, red tomato fruits were infiltrated by different concentration of antioxidants (Vitamin C, L-galactonic acid-γ-lactone and Butylated hydroxyanisole (BHA) and also treated by hot water. The color and firmness of the fruits were measured by pigment analyzer and Zwick, respectively. Dessicator with vacuum pump was used for infiltration of antioxidants and water. Antioxidants were infiltrated through the scar of the fruits by applying 400 Mbar pressure for 15 sec. for each concentration. Red tomatoes were treated in hot water at 40, 45 and 50°C for 2, 5 and 10 min each. All antioxidant infiltrated and hot water treated fruits were stored at 4°C for three weeks. Statistically significant difference was not observed on color and firmness among different fruits treated by different concentration of antioxidants. Hot water treatment also showed no significant difference on color value between treated and non-treated fruits. However, hot water treated fruits scored significantly higher firmness than non-treated fruits. In general, the results showed that antioxidants as well as hot water treatment did not maintain accumulated lycopene content of the red tomato fruits which, stored at chilling temperature.