Quality Analysis and Evaluation of Different Batches of Pitaya Fruit (Hylocereus) in South China

Pitaya is a tropical and subtropical fruit; it can produce several batches fruit in one year. To find out the fruit quality differences between various batches in the same year in Guangzhou, South China, 11 pitaya varieties were used as the materials. Comparative analysis was performed between these varieties of each batch by 14 indexes, comprehensive evaluation and ranking were evaluated by the principal component analysis (PCA). Results showed that the red-peel and red-pulp pitaya has the longer fruit period and could obtain more batches fruits. By comparing the fruit quality of these 11 varieties in different batches: Except "Guanhuahong," fruit weight is significant different between other 10 varieties. The edible rate of fruits from 2(nd) and 3(rd) batches is significantly higher than others. The hardness, total sugar, total acid, betalain, total phenol, and flavonoids were significant difference between batches. The PCA results indicated that in most varieties, the 1(st), 8(th), 9(th) batches are generally with heavier fruit, better color, harder and sweeter; more stable antioxidant compounds were shown in 6(th), 7(th), 8(th), 9(th) batches; the 3(rd), 4(th), 5(th), and 6(th) batches are smaller, softer, lower soluble sugar and higher titratable acid. Pitaya fruit quality and tastes from various batches are different in the same year, the climate may be the main factor. The fruits of 7(th), 8(th) and 9(th) batches picking from Sep to Nov has better quality and higher economic value. This research has practical application value and could provide theoretical basis for the production of pitaya.