Abstract: Adenosine triphosphate (ATP) treatment effects on the quality maintenance of fresh-cut cucumber and the contents of bioactive compounds such as total phenolic and γ-aminobutyric acid (GABA) in fresh-cut cucumber were studied. Fresh-cut cucumber was soaked separately in 0, 0.8, 1.2, 1.6 and 2.0 mmol/L ATP solution for 10 min. To determine the appropriate concentration of ATP treatment, fruit quality parameters, and total phenol and GABA contents were measured during storage at 10 ℃ for 72 h. Furthermore, the regulatory mechanism of ATP treatment at the appropriate concentration on total phenol and GABA accumulation. The results indicated that compared with the control group, ATP treatment maintained better color quality and lower total bacterial count (TBC), delayed the decrease in firmness and ascorbic acid content, and promoted an increase in the accumulation of total phenols and GABA in fresh-cut cucumber, the effect being most pronounced at an ATP concentration of 1.6 mmol/L. Furthermore, compared with the control group, 1.6 mmol/L ATP treatment increased the activities of phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), cinnamate-4-hydroxylase (C4H), glutamate decarboxylase (GAD), diamine oxidase (DAO), polyamine oxidase (PAO) and 4-amino aldehyde dehydrogenase (AMADH), and promoted the synthesis of phenolic substances and the decomposition of glutamate (Glu) and polyamine to produce GABA, thus increasing total phenol and GABA contents in fresh-cut cucumber. These results indicated that ATP treatment could not only delay quality deterioration, but also increase total phenol and GABA contents, thereby improving the antioxidant capacity and nutritional value of fresh-cut cucumber.

Key words: adenosine triphosphate; fresh-cut cucumber; quality; total phenolics; γ-aminobutyric acid