‘Toyonoka’ and ‘Nyoho’ strawberries were purchased from retail stores, and ‘Hoko- wase’ berries were obtained from the greenhouse production unit at the experimental farm of the Osaka Prefecture University. After the calyxes had been removed, the berries were washed with tap water. They were frozen with dry ice and then with liquid nitrogen to speed up freezing and also to avoid cracking of berries. The frozen berries were wrapped in aluminum foil, sealed in polyethylene bags and stored at -20°C -40°C and -80°C.