Regularity for change of respiration intensity of different sweet potato varieties at normal atmospheric temperature

Respiration is an important physiological function for postharvest agricultural products and an important factor of affecting their storage and transportation. Physiological function of postharvest agricultural products might be understood by determining their respiratory intensity so as to obtain basic data for low-temperature storage, control atmospheric storage and calculation of respiratory heat. The results showed that the respiratory intensities of eight species of sweet potatoes such as Umbilicus coloured potato, Jing VI potato, American black potato, Golden sea II, Japanese yellow potato, Fruit potato, Su Ⅷ potato, Banana potato were very different at normal temperature during the period of storage. Japanese yellow potato was the best one for storage at normal atmospheric temperature, the weight loss ratio per day of it was only 0.45%, then umbilicus coloured potato and Su Ⅷ potato took the second place. American black potato and Jing VI potato were the last. The initial respiratory intensities of eight species of sweet potatoes was 0.09－0.47 mg/(kg·h), in which the lowest was Su Ⅷ potato, and the highest was Jing VI potato. The respiratory intensities of different sweet potatoes of long storage at normal atmospheric temperature were Japanese yellow potato 0.52 mg/(kg·h), Su Ⅷ potato 0.53 mg/(kg·h), Fruit potato 0.57 mg/(kg·h)，Umbilicus coloured potato 0.58 mg/(kg·h), Banana potato 0.59 mg/(kg·h), Golden sea II 0.60 mg/(kg·h), American black potato 0.65 mg/(kg·h), Jing VI potato 0.68 mg/(kg·h), respectively. The storage time of different sweet potatoes before the occurrence of respiratory climacteric happened were Japanese yellow potato 7 d, Banana potato 7 d, Su Ⅷ potato 9 d, Fruit potato 9 d, American black potato 10 d, Jing VI potato 11 d, Umbilicus coloured potato 11 d and Golden sea II 13 d. The characteristic of sweet potatoes of long storage at normal atmospheric temperature was low respiratory intensity during climacteric period.