Abstract: In order to investigate the effect of exogenous L-cysteine treatment on the storage quality of ‘Qingcui’ plum fruit (Prunus salicina Lindell), the fruit were soaked in L-cysteine solutions at 0, 100, 500 and 1 000 mg/L for 10 min, separately, and then stored at 20 ℃ and 85%-90% relative humidity. The results showed that L-cysteine at all three concentrations could reduce the natural infection incidence and disease index of ‘Qingcui’ plum fruit during storage at room temperature. Treatments with 500 and 1 000 mg/L L-cysteine could inhibit the yellowing and softening process, delay the decrease in the contents of total soluble solid, titratable acid and ascorbic acid, and inhibit the increase in mass loss, relative electrical conductivity and malondlaldehyde (MDA) content. The effect was found to be better at 1 000 mg/L L-cysteine concentration. Meantime, 1 000 mg/L L-cysteine treatment increased the contents of endogenous cysteine, glutamate, aspartate and proline. Therefore, exogenous L-cysteine treatment at optimal concentration can effectively delay the senescence and quality loss of ‘Qingcui’ plum fruit after harvest.

Key words: L-cysteine, ‘Qingcui’ plum fruit, storage quality