Ascorbic acid and dehydroascorbic acid content of blanched sweet green pepper during chilled storage in modified atmospheres.

Sweet green pepper (Capsicum annuum L.) cut into pieces was analysed for ascorbic acid (AA) and dehydroascorbic acid (DHAA) content before and after blanching, after 1, 4 and 7 days of chilled storage in modified atmosphere, and after reheating. No difference in retention of AA was noted between storage in 2 and 4% O2 atmospheres, whereas retention during storage in air was significantly lower. Production of DHAA during storage increased with increased O2 content in the atmosphere. After 7 days of storage, DHAA contributed 10-35% of the total AA, and DHAA contributed 12-25% after reheating, depending on the O2 content in the atmosphere. Since the vitamin activity of DHAA is considered to be the same as that of AA, it is concluded that the content of DHAA in processed green pepper is of importance and should be measured together with AA.