Physicochemical Properties of Pre-Harvest Sprouted Hard Spring Wheat

Pre-Harvest Sprouting (PHS) can cause severe economic loss in wheat grown across many areas of the world. Prolonged rainfall before harvest and high temperatures can contribute to the occurrence of PHS. Grain growers prefer wheat genotypes with low susceptibility to PHS. The objective of this study was to examine the physicochemical properties of Hard Red Spring Wheat (HRSW) and Hard White Spring Wheat (HWSW) affected by PHS. Physicochemical properties of the starch and protein in HRSW and HWSW were significantly affected by PHS. ?-Amylase was determined using an Azurine-crosslinked amylose substrate (AZCL-Amylose; Megazyme Co., Ltd). Endo-protease activity was determined using an Azurine-crosslinked substrate (Protazyme AK tablet; Megazyme Co., Ltd). Mean value of ?-amylase of PHS damaged wheat (2.00 CU/g) was 17 times greater than sound wheat (0.12 CU/g). Mean value of endo-protease of PHS damaged wheat (2.30 A_{590}/g/h) was 1.6 times higher than sound wheat (1.44 A_{590}/g/h). PHS increased both ?-amylase and endo-protease activities, resulting in the hydrolysis of starch and protein molecules. However, the increased endo-protease activity was not as significant as the increase in the ?-amylase activity in PHS wheat. In a scale of 1.0-9.0, the wheat genotypes had significantly different sprouting scores ranging from 2.5 to 7.8, which had positive correlations with ?-amylase and endoprotease activities (P