Abstract:

Xindali No. 1 vegetable soybean was used as materials to investigate the changes of sucrose metabolism and
related enzyme activities during storage at different temperatures (1, 5, 10, and 20 ℃). Results demonstrated that the
contents of sucrose, fructose and glucose in vegetable soybean showed an overall downward trend, while storage at 1 ℃
inhibited the degradation of sucrose significantly. The activity of acid invertase (AI) reached the peak level on the first
day, and then decreased gradually. It was not affected by various temperatures. The activity of neutral invertase (NI)
increased until the fourth day at 20 ℃, while no significant difference was found among other storage temperature groups
(P ＞ 0.05). The activity of sucrose synthase (SS) increased rapidly with a slight decrease at first, and reached the peak level
on the fourth day, and then decreased gradually. Furthermore, the activity of sucrose phosphate synthase (SPS) showed a
decreasing trend. It had a significantly positive correlation with sucrose content (P ＜ 0.01), and a positive correlation with
the content of fructose (P ＜ 0.05). However, no positive correlation was found between other enzymes and sugar content
(P ＞ 0.05). Therefore, SPS might play an important role in the sucrose degradation of Xindali No. 1 vegetable soybean.

Key words: vegetable soybean, storage temperature, sucrose metabolism, sucrose phosphate synthase (SPS)