关键词: 杨梅, 有机酸, 糖, 代谢, 成熟

Abstract:

The contents of 7 organic acids, titratable acids, soluble sugars, TSS, reducing sugars and sucrose and sugar/
acid ratio in bayberry fruits from three cultivars, Dongkui, Dawumei and Local Pink, during the maturity period were
measured to clarify dynamic changes of organic acids and sugars and the optimal harvest time. The results showed that: (1)
the most important organic acid in 3 varieties was citric acid during the maturity period representing 79.58% to 93.61% of
the total titratable acids, followed by succinic acid and malic acid accounting for 1.68% to 5.73% and 1.57% to 3.88% of
the total titratable acids. In addition, lactic acid, acetic acid, oxalic acid and tartaric acid were also contained. (2) changes
of acids in the bayberry cultivars followed a similar trend during the maturity period; titratable acid, citric acid and
succinic acid contents showed a downward trend, while malic acid, lactic acid and acetic acid contents revealed a gradual
increase. Moreover, oxalic acid contents in Dongkui and Dawumei revealed a decrease, while it exhibited a gradual
increase in Local Pink. (3) reducing sugar, soluble sugar and sucrose showed an initial increase and then a decrease,
indicating a reducing phenomenon of sugars during the later stage of maturity period. These observations show that the
compositions, contents and dynamic change of sugars and organic acids are the major factors affecting sugar/acid ratio
and flavor of waxberry fruits. Acid contents, sugar contents and sugar/acid ratios of the three bayberry cultivars during
the maturity period had a significant difference, among which Dongkui and Dawumei had the lowest content of total acid
and citric acid, and the highest sugar content and sugar acid ratio. (4) the optimal harvest time for all the cultivars was in
mid to late May.

Key words: bayberry, organic acid, sugar, dynamic change, maturation