Effects of forced-air precooling on fruit quality and antioxidant system of apricot were evaluated in this study. Apricots were forced-air precooled for 24 hr at 08C, and then stored at 08C for up to 20 days. Results showed that precooling treatment slowed down a decrease of titratable acidity (TA) and total soluble solids (TSS) during storage period, whereas it had no effect on pH and L* value. On the 15th day of storage, associated with higher flavonoids content, precooled fruit had 73.6% higher DPPH and 183% higher ABTS radical-scavenging activities than the control. In addition, the peak of ascorbate peroxidase (APX) was earlier, and H 2 O 2 content was reduced by precooling treatment with respect to control. These results indicate that precooling treatment could maintain the quality of apricot by enhancing antioxidant activity.
Practical applicationsFruit with high antioxidants implies high nutritional value. In this study, we found forced air precooling induced an increase of antioxidant activity of apricots. Precooling treatment should be used to enhance the quality and nutritional value of apricots.
| I N TR ODU C TI ONApricot is a widely cultivated fruit tree in the Mediterranean and Asian regions. Due to their pleasant aroma, sweetness and juiciness, apricots are appreciated by consumers (Solis-Solis, Calder on-Santoyo, SchorrGalindo, Luna-Solano, & Ragazzo-S anchez, 2007). However, apricots, which present typical respiration climacteric, suffer from rapid softening and decay after harvest. Thus, apricot fruit have limited postharvest life (Wang et al., 2015).Because respiration rate and ethylene are reduced in cold storage, cold storage is the most effective method among postharvest treatments to prolong fruit shelf life. Ripe apricot fruit can be stored at room temperature for 2-3 days without losing edible value, while it can be stored at 08C for a few weeks (Dong, Lurie, & Zhou, 2002).Precooling can rapidly remove field heat prior to transportation or storage, and it is a critical step in the food cold chain (Defraeye et al., 2014). After precooled, respiration rate of fruits is reduced and the process of senescence is retarded. Pathogens development is also inhibited, and fruit decay is decreased (Nilsson, 2000). Thereby, postharvest changes of climacteric fruits are delayed when fruits are precooled immediately and stored at low temperatures. Moreover, precooling can reduce cooling load of storage rooms (Brosnan & Sun, 2001). For apricots, forced-air precooling is adapted to a wide range of commodities (Mitchell, 1992). Agar et al. (2006) also found that forced-air precooling at 08C extended the shelf-life and improved the appearance of apricots.Besides its delicious taste, excellent flavor and attractive colors, apricot is also a fruit of high nutritional value (Drogoudi et al., 2008).Apricot fruits contain phytonutrients, such as flavonoids and polyphenols, which can act as antioxidants and protect against cancers and heart diseases by reducing the reactive oxygen species in human body ...