Abstract:  This paper described the research of four kinds of chitosan compounds freshening reagents in keeping tomato fresh. The plant physiological and biochemical indexes were detected interval during preservation days. The result showed: after 12 days of dealing with the tomato, the freshening time of the freshening reagent C was longer than other kinds, with the loss rate as 1.17%, the decay ratio as zero, the respiration intensity was 5.82mg/kg·h and the vitamin C content as 180mg/100g.

Key words: chitosan, preservation, tomato