The Effects of Hot and Cold Water Treatment on Quality Parameters and Enzymatic Activity in Chestnut

Abstract

This study was carried out in order to limit the biochemical and enzymatic changes occurred after harvested in a variety of (Castanea sativa Mill. cv. 'Sariaslama') chestnuts to prolong the stored period by reduce the loss of quality. Before samples were stored, hot (46±2 °C, 45 minutes) and cold water (15±2 °C, 8 days) treatments were performed. After the hot and cold water treatments the fruits were stored in normal (NA) and controlled atmosphere (CA). In CA storage the fruits were kept in three different atmosphere combinations: (10% CO2, 2% O2; 15% CO2, 2% O2; 20% CO2, 2% O2). In both storage methods, chestnuts were stored for 5 months in 0±1 °C temperature and 90±5% relative humidity conditions. During the storage, parameters such as weight loss (%), content of relative water (%), polyphenol oxidase (PPO) (units mg-1 protein), soluble solids (°brix), starch (mg mL-1), total sugar (mg mL-1), vitamin C (mg 100 mL-1), macro (potassium, phosphorus, calcium, sodium) and micro (iron, magnesium) elements (mg 100 g-1) were examined in the fruit samples taken. Maximum weight loss was examined in the fruit kept in NA whereas total sugar and starch showed less of a change in CA in this present study. PPO enzymatic activity can successfully control with hot water treatment in 15% CO2, 2% O2 gas combination. When soluble solids was examined, a smaller degree of change was observed in the fruit stored in CA. Promising results were achieved with the fruit that was stored using hot water treatment and 15% CO2, 2% O2 combination in this study, which was conducted on the ‘Sariaslama’chestnut.