Abstract:

The effects of hot-air treatment (45 ℃ for 3.5 h) on fruit decay and antioxidant activity as well as the expression of
antioxidant enzymes-related genes in strawberry fruit during storage at 20 ℃ for 4 d were investigated. The results indicated that
the hot-air treatment significantly reduced fruit decay incidence, delayed the decreases in fruit firmness and the contents of total
phenolics, total flavonoids and vitamin C, retarded the accumulation of anthocyanin, and maintained higher diphenylpicrylhydrazyl
(DPPH) free radical scavenging activity and reducing power. Meanwhile, the expression of genes encoding flavonol synthase,
chalcone synthase and phenylalanine ammonia-lyase were enhanced whereas the gene expression levels of beta xylosidase and
anthocyanidin synthase were reduced by this hot air treatment. These results demonstrate that hot-air treatment can maintain fruit
quality and antioxidant activity by regulating the expression of quality-related genes.

Key words: strawberry, hot-air treatment, quality, antioxidant activity, gene expression