Effects of water deficit during maturation on amino acids and jujube fruit eating quality

Pear-jujube yield and fruit characteristics can be clearly modified by a water deficit imposed during fruit maturation period. One essential (cystine (Cys-cys)) and seven non-essential (4-hydroxyproline (p-Hyp), α-aminoadipic acid (AADA), ornithine (orn), β-aminoisobutyric acid (BAIB), α-amino-n-butyric acid (AABA), cystathionine (Cysta) and homocystine (Hcys-cys)) amino acids were identified for the first time. Fruits from plants exposed to a moderate water deficit during the maturation stage (T1) initiated the ripening phase earlier than control (T0) fruits and showed an improved eating quality. Fruits resulting from severe water deficit (T2) showed changes in their physical characteristics and reached more advanced degree of ripening than T0 and T1 fruits, improving not only most of fruit chemical characteristics that make up the taste but also the nutritional value. The decrease in the asparagine (Asn) content of the fruit as a result of severe water deficit is a positive aspect, which prevents acrylamide formation during heat-processing of the fruit.