Abstract:

Loquat fruits (Eriobotrya japonica Lindl. cv Jiefangzhong) were harvested from Fujian province and response
surface methodology (RSM) was used to study the effects of different combined treatment conditions with hot water at
different temperatures (40, 45, 50 ℃), for different time periods (5, 10, and 15 min), and three concentrations of glycine
betaine (5, 10, and 15 mmol/L) on the quality of loquat fruits during subsequent storage at 1 ℃. At the end of storage,
the changes in fruit internal browning, firmness and extractable juice were measured. A second-order polynomial model
describing each of the three responses was established and its goodness of fit was analyzed. In addition, the model was validated.
The response surface analysis was carried out to identify the factors with significant influence on fruit quality and the interactions
between them. The optimal combined treatment conditions for reducing chilling injury in loquat fruit were determined as follows:
hot water temperature, 44.36 ℃; treatment time, 9.14 min; and glycine betaine concentration, 10.65 mmol/L. The optimized
combined treatment was more effective in inhibiting chilling injury of loquat fruit and maintaining quality than either alone.

Key words: loquat fruit, chilling injury, glycine betaine, hot water treatment, combined treatment, response surface methodology