Vegetable soybean is becoming increasingly popular in the U.S. because of its rich source of isoflavones,
folic acid, and other nutrients. The objective of this study was to investigate various blanching and
storage conditions in order to identify the proper post-harvest management strategy in preserving sugar
composition of vegetable soybean during storage. Fresh soybean pods of two vegetable soybean genotypes
were stored at 4 C for 30 days or 25 C for 8e12 days in fresh air or nitrogen atmosphere. Shelled
seeds and intact pods were blanched in boiling water or steamed at 100 C for 10 min. All blanched
soybean was stored at 20 C and sampled monthly for 6 months for sugar analysis. Glucose, fructose
and sucrose decreased gradually in fresh soybean when stored at 4 C in air or nitrogen atmosphere for
28 days. Soybean stored at 25 C in open air showed a rapid decrease of sucrose in the first 24 h, and then
followed by a gradual increase; whereas oligosaccharides accumulated significantly during storage.
Significant degradation in all sugars was found in soybean stored in nitrogen atmosphere at 25 C.
Soluble sugars decreased from leaching during the water blanching and cooling treatment of vegetable
soybean seeds. Steam blanching and the presence of pod effectively retained soluble sugars in vegetable
soybean during thermal treatment.