Submitted to: South Texas Melon Committee Annual Research Report
Publication Type: Other
Publication Acceptance Date: November 16, 1995
Publication Date: N/A
Immediately after irradiation, membrane H-ATPase enzyme activity was retarded by 14%, reduced H-ATPase activity is associated with membrane breakdown or senescence. Other enzymes responsible for destroying membrane proteins, phopholipids and sterols also must have experienced reduced activity as total protein (ug, total phospholipid/ug protein contents were higher, and free sterols (mole%) contents were lower compared to non-irradiated control fruits. Thus, immediately after irradiation enzyme activities are effectively reduced. The long term effects of irradiation on cantaloupe fruit following 10 days of storage demonstrated that H-ATPase activity declined by 9% for irradiated fruit but for control fruits the activity declined by 21%. Total protein following storage declined 34% for irradiated, and 49% in control fruits. Total phospholipid declined 9% in irradiated and 16% in control fruits. Free sterols, and increase in their content indicates increased membrane senescence, increased 9% in irradiated and 26% in control fruits. Thus, irradiation which immediately reduced enzyme activity, as a result, slowed the enzymatic degradation of protein, phospholipids and sterols, the essential building blocks of the membrane. The result, therefore, is a slowing of cantaloupe senescence.