Abstract: The effects of different storage temperatures on the quality and total phenolic and γ-aminobutyric acid (GABA) content of fresh-cut carrot were investigated. Fresh-cut carrots were cut into shreds and stored at 4, 10 and 20 ℃ for 6, 4 and 2 days, respectively. The results indicated that total bacterial count, mass loss rate and whiteness of fresh-cut carrot increased while total carotene and ascorbic acid content decreased during storage. Compared with storage at 10 and 20 ℃, low temperature storage at 4 ℃ significantly inhibited the increase of total bacterial count, mass loss rate and whiteness and the decrease of β-carotene and ascorbic acid contents. Moreover, total phenolic and GABA content as well as 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical scavenging activity increased steadily during storage, while L-phenylalanine ammonialyase (PAL) and glutamate decarboxylase (GAD) activity increased first and then decreased. Total phenolic and GABA content, DPPH radical scavenging capacity, and PAL and GAD activity were significantly higher when stored at 20 ℃ than at 4 and 10 ℃. These results indicated that conventional low temperature storage could maintain the quality of fresh-cut carrot, whereas storage at a higher temperature for a shorter period could promote the synthesis and accumulation of phenolic compounds and GABA while ensuring the quality and safety of fresh-cut carrot, thus enhancing the antioxidant activity and improving the nutritional value of fresh-cut carrot.

Key words: fresh-cut carrot, storage temperature, quality, total phenolics, γ-aminobutyric acid