The effect of boiling and baking process on total phenolic compounds and antioxidant capacity of Osmanoğlu and Sarıaşlama chestnuts grow in Bursa

Abstract

Chestnut is a fruit with high carbohydrate content, low-oil ratio and protein content, including minerals, vitamins, amino acids and phenolic compounds which can have antioxidant properties. It has been determined that the amount and composition of phenolic components could change in according to environmental and growing conditions, and the variety of chestnuts having impact on protein content. This study was conducted to investigate the possible effects of boiling and baking on some physical and chemical properties, antioxidant activity and total phenolic content of Osmanoğlu and Sarıaşlama chestnut varieties grown in Bursa. According to the results of the present study, some physical and biochemical properties of raw chestnut were determined as humidity 48.78–56.57 %, ash 1.11–1.27 g 100 g-1, water activity 0.705–0.844, pH 7.03–7.29, color L* 60.52±2,64; a* 0.13±0,18; b* 12.39±1.57. The total phenolic compounds content was 129.17±6.23 mg GAE (gallic acid equailent) kg-1 in raw chestnuts, 180.97±18.25 mg GAE kg-1 in boiled chestnuts, and 149.86±7.95 mg GAE kg-1 in baked chestnuts. Also, the antioxidant capacity found like 0.42±0.01 μmol AAE (ascorbic acid equivalent) g-1 for raw chestnuts, 0.31±0.03 μmol AAE g-1 for boiled chestnuts, and 0.40±0.01 μmol AAE g-1 of baked chestnuts. It was determined that while the application of the boiling process caused a significant decrease in the antioxidant activity of chestnuts, the application of the baking process did not cause any meaningful change on the antioxidant capacity of the chestnuts. It was determined that there was a significant increase in the total phenolic compounds content with the boiling and baking process compared to raw chestnuts.