Nghiên cứu sự chuyển hoá sinh lý, hóa sinh theo tuổi phát triển của quả hồng Nhân Hậu (Diospyros kaki L.f.) trồng tại Thanh Hóa

Abstract

The physiological and biochemical metabolism of Nhan Hau persimmon variety collected in Thanh Hoa province from formation to maturity was studied in order to determine the physiological ripening time of the fruit, which is crucial for collection and preservation. Fruits were collected at 4, 8, 12, 15, 17, 19, 20, 21 & 23 weeks and surveyed for size, pigment content, reducing sugar, starch, total acidity, vitamin C, pectin and tannin. Results showed that persimmons fruit reached the maximum size at week 21 (6.39 cm in length, 6.17 cm in diameter). The content of chlorophyll a and b increased gradually from fruit formation to week 15 (0.43 mg/100 g and 0.61 mg/100 g, respectively), then decreased rapidly until the fruit was fully ripe. The concentration of carotenoids increased gradually until the fruit ripened (reaching 0.81 mg/100 g at week 23). Starch content and total acidity content increased gradually and peaked at week 17 (starch reached 7.61%, total acidity reached 74.70 mg/100 g), then gradually decreased. Reducing sugars and vitamin C content increased during the early stages and peaked at week 21 (reducing sugar reached 14.11%, vitamin C reached 46.54 mg/100 g), then decreased gradually. Pectin and tannin content increased and reached their maximum at week 15 (pectin reached 4.04%, tannin reached 2.02%), then decreased. These results show that the Nhan Hau persimmon fruit should be harvested at physiological maturity (21 weeks old) to ensure the high nutritional value and quality of the fruit during storage.