Effect of Roasting on the Physicochemical and Antioxidant Characteristics of Hihatsumodoki (Piper Retrofractum Vahl) Dried Fruit

Abstract

　The effect of roasting on the physicochemical and antioxidant properties of dried hihatsumodoki (Piper retrofractum Vahl) peppers was evaluated. A temperature-dependent loss in mass was observed. However, linear dimensions and hardness showed different patterns depending on the temperature. In particular, roasting at 180℃ was accompanied by an increase in size and a drastic loss of hardness. Color parameters (Hunter a^＊ and b^＊ values) were also affected by the roasting conditions. The piperine content of the dried pepper fruits was significantly reduced by roasting at 140℃ or 180℃ for up to 30 min. This treatment also resulted in a significant loss in the 1,1-diphenyl-2-picrylhydrazine (DPPH) radical-scavenging activity in parallel with a decrease in the piperine content; however, the total phenolic content was not affected. Therefore, considering the food qualities, including piperine content, and antioxidant properties, we propose that roasting at 120℃ for up to 30 min was a desirable condition to produce spices and also retain their functional value.