• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.719-724
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• 2010

This study investigated the physicochemical characteristics and antioxidant activities of Daehak waxy corns harvested at different times. Daehak waxy corns were harvested at 4 days before suitable time (BST), suitable time (ST) and 4 days after suitable time (AST). As harvest time was delayed, weight, length and width of kernel, the crude ash, lipid and protein contents significantly increased. Fructose, glucose and sucrose contents of BST were higher than those of ST and AST. Copper, sodium, calcium and potassium contents of BST in Daehak waxy corns increased on different times, and contents of ferrous and zinc did not show any significantly difference. The major fatty acids were oleic acid (48.58~49.96%), palmitic acid (19.50~20.64%) and palmitoleic acid (18.70~23.77%) in Daehak waxy corns with different harvest times. The highest total polyphenol content and total antioxidant capacity of EtOH extracts from AST were 104.45 mg/100 g and 20.53 mg AA eq/100 g, respectively. There was a high correlation between total polyphenol content and $IC_{50}$ value of electron donating ability of EtOH extracts from Daehak waxy corns harvested at different times, or total antioxidant capacity (p<0.01).

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.573-579
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• 2010

This study investigated starch properties of 'Daehak waxy corn (DWC)' with different harvest times. The DWCs were harvested at 4 days before suitable time (BST), suitable time (ST) and 4 days after suitable time (AST). As harvest time was delayed, starch yield and amylopectin content of DWC starch increased from 43.21 to 52.73%, and from 90.79 to 92.83% based on dry weight, respectively. As harvest time was postponed, enzymatic digestibility and water solubility of DWC starch decreased from 81.43 to 80.58%, and from 10.23 to 9.23%. However, water binding capacity and swelling power of DWC starch increased from 227.94 to 244.88%, and from 24.75 to 29.74%, respectively. Retrogradation viscosity of starch was the lowest in DWC harvested at AST. There was a high correlation coefficient among starch properties of DWC, such as starch yield, enzymatic digestibility, water binding capacity, swelling power, water solubility and retrogradation viscosity (p<0.01). As harvest time was deferred, enzymatic digestibility, water solubility and retrogradation viscosity decreased; however, amylopectin content increased, and water binding capacity and swelling power significantly increased with increasing amylopectin content.