Study on the changes of some physiological and biochemical parameters during the growth and development of Indian jujube fruits (Ziziphus mauritiana Lam.) cultivated in Thanh Hoa province, Viet Nam

Abstract

     The study was conducted to evaluate physiological and biochemical parameters during the development of Indian jujube fruits (Ziziphus mauritiana Lam.) grown in Thanh Hoa province, from the 2^nd to the 13^th week after the anthesis, to determine the optimal harvest time. The fruit size and fresh weight were measured using a digital caliper and electronic scale, while the contents of pigments, reducing sugars, starch, and total organic acids were determined using spectrophotometry, Bertrand's method, acid hydrolysis, and neutralization, respectively. The results showed that the fruit length, diameter, and fresh weight reached their maximum values at the 12^th week. The chlorophyll content gradually decreased, whereas the carotenoid content continuously increased with fruit age. The reducing sugar content steadily increased, peaking at the 12^th week, followed by a slight decline. The starch content peaked at the 6^th week and then gradually decreased, while the total organic acid content reached its maximum at the 10^th week and subsequently declined. The study recommends harvesting Indian jujube fruits at the 12^th week to achieve optimal nutritional value and quality. These findings provide essential scientific insights to support harvest management and enhance the economic value of Indian jujube in agricultural production.