2. Materials and Methods
2.1. Fruits and Low Temperature Conditioning Treatment
Huangguan pears (Pyrus bretschneideri Rehd cv. Huangguan) were harvested from three pear orchards in Xinji
City, Hebei Province, China on 20 August, 2014 and 16 August, 2013. Pears were placed in single layer trays
and transported to our laboratory in the same day. Fruit was selected for uniformity of size and appearance. All
harvested pears were chosen without diseases, bruises, or injuries.
The fruits were given a low temperature conditioning treatment at 8˚C - 9˚C for 1, 3, 6, and 9 days, respectively;
fruits without LTC treatment were regarded as control. All the fruits were stored in −1˚C - 0˚C for 250
days; Fruits were taken out for browning and quality evaluation every 50 days. To investigate the quality
changes in shelf life, shelf trials were undertaken in the temperature of 20˚C - 25˚C and humidity of 65% - 70%.
The 20 fruits were used for each of the three replicates.