R. Locher et P. Bucheli, COMPARISON OF SOLUBLE SUGAR DEGRADATION IN SOYBEAN SEED UNDER SIMULATED TROPICAL STORAGE-CONDITIONS, Crop science, 38(5), 1998, pp. 1229-1235
Storage of soybean [Glycine max (L.) Merr.] seed under tropical condit
ions can lead to deterioration that affects product taste and color. A
study was designed to assess the effect of extreme storage conditions
on the degradation of soluble sugars and to relate these changes to s
eed deterioration. Seed of six cultivars of soybean were stored for 9
mo. under control (4 degrees C, 45% RH) and simulated tropical (30 deg
rees C, 82% RH) conditions. Soluble sugar metabolism was monitored by
high performance anion exchange chromatography coupled to pulsed amper
ometric detection (HPAE-PAD). Soluble sugar content was constant or on
ly slightly affected under control conditions. However, substantial hy
drolysis of stachyose, raffinose, and verbascose occurred under simula
ted tropical conditions. The resulting release of glucose and galactos
e, combined with the degree of hydrolysis of oligosaccharides, appears
to be strongly linked to soybean seed quality as indicated by seed ge
rmination. Storage behavior was cultivar dependent, pointing to the im
portance of selecting cultivars for storability in tropical countries.
Determination of glucose seems to be a sensitive analytical and pract
ical tool for monitoring soybean seed quality and deterioration under
extreme climatic conditions.