Effects of peeling, drying temperature, and sodium metabisulfite treatment on physicochemical characteristics and antioxidant activities of Asian pear powders

Abstract

The effects of peeling, drying temperatures (55–65 °C), and pretreatment with sodium metabisulfite (SMS) on the physicochemical characteristics and antioxidative activities of Asian pear powder were investigated. The powders from SMS-treated peeled and unpeeled pears (PSP and USP, respectively) had higher L* values and water absorption indices than peeled and unpeeled pears without SMS treatment (PP and UP, respectively) at different drying temperatures. However, the water solubility indices of PSP and USP were lower than those of PP and UP at low temperatures and water solubility increased as drying temperatures increased. Total phenolic, ascorbic acid, chlorogenic acid, and caffeic acid contents and antioxidative activities were higher in USP and UP than in PSP and PP and, with the exception of ascorbic acid, increased with increasing drying temperature. The arbutin content of UP was higher than that of PP and was not influenced by drying temperatures and SMS pretreatment. In conclusion, SMS treatment before drying at 65 °C could result in higher quality Asian pear powder. Practical applications Asian pear fruits are rich in various antioxidants and are good sources of sugars. Therefore, they have been developed as food ingredients and are widely used in various foods, including cakes and biscuits. It is necessary to study optimal pretreatment conditions and drying temperatures to retain more functional components in Asian pear powder. Our study demonstrates optimal conditions to produce high quality Asian pear powder that can be used in various food formulations to improve nutritional value, flavor, color, and sweetness.