Abstract
We investigated the effects of soaking at high temperature on the water absorption, fracture characteristics, sensory evaluation and chemical components of boiled black soybean seeds. The seeds were soaked in water at 20°C for one hour to 20 hours and at six temperatures from 30°C to 80°C for two hours before boiling. Soaking at 20°C achieved equilibrium after 10 hours in the increasing ratio of seed weight after boiling and the fracture characteristics of the boiled seeds. Soaking for two hours increased the increasing ratio of seed weight and decreased the fracture force of the boiled seeds with increasing temperature from 20°C to 60°C, and achieved equilibrium at temperatures above 60°C. Soaking for two hours at temperatures above 70°C markedly increased the soluble solid content, and soaking above 60°C markedly inhibited the cracked seed rate. The effects of soaking at 60°C for two hours on the sensory evaluation and chemical components were comparable to those of soaking at 20°C for 10 hours. It is considered that soaking at 60°C for two hours was most effective in the cooking process to ensure the best quality of the boiled seeds.
