Objective  Flavor of Liuyuezao pummelos as affected by the sugar and acid contents in the fruits during storage at ambient temperature was studied in order to provide a clue for breeding new variety.

  Method  Contents of soluble sugars (i.e., glucose, fructose, and sucrose) and organic acids (including citric acid, malic acid, quinic acid, aconitic acid, tartaric acid, succinic acid, and α- ketoglutarate acid) in the fruits of Liuyuezao pummelo, as well as Guanximiyou pummelo as control, during storage at ambient temperature were monitored using ultra-high performance liquid chromatography (UPLC) for a correlation analysis with the eating quality of the fruits.

  Result   In storage, the contents of total acid, citric acid, and malic acid in the juice sacs of Liuyuezao pummelos increased to peak in 35 d at 81.18%, 84.17%, and 1.90 times, respectively, of those in Guanximiyou. Glucose and fructose in Liuyuezao pummelos declined initially at the beginning of the storage but reached the minimum in 10 d at 1.30 times and 1.47 times, respectively, of those in Guanximiyou. Meanwhile, sucrose increased at first and followed by a decline with the highest that was 84.45% of Guanximiyou appeared after 10 d of storage. The sugar/acid ratio of the fruits decreased gradually to arrive at the minimum of 1.27 times of Guanximiyou in 35 d. There was a significant inverse correlation between the ratio and the content of malic acid (P＜0.01).

  Conclusion   At ambient temperature, the stored Liuyuezao pummelos had relative lower contents of citric acid and sucrose but higher sugar/acid ratio, malic acid, fructose, and glucose than Guanximiyou. That, perhaps, differentiated the quality of the two pummelo varieties concerning the sensory appealing.