Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 2003
Publication Date: April 4, 2004
Citation: Lamikanra, O., Watson, M.A. 2004. Storage effects on lipase activity in fresh-cut cantaloupe melon. Journal of Food Science. 69:126-130. Interpretive Summary: Flavor, a critical quality parameter, deteriorates rapidly in cut fruits during refrigerated storage. Our research previously suggested that a rapid breakdown of lipid components occur during storage of cut fruits that potentially contributes to loss of freshness. The effect of storage on an enzyme that initiates lipid breakdown (lipase) was determined as well as the properties of the enzyme. The enzyme was stable during storage of cut cantaloupe melon at 4 oC for 7 days, an indication of its potential involvement in lipid deterioration in the stored fruit. Cantaloupe melon lipase is also very active at temperatures up to 70 oC but not stable for prolonged periods of time at this temperature. Mild heat treatments for short periods of time would likely increase lipase activity in the cut fruit. Calcium, a common processing aid for cut fruits, also reduces lipase activity. The information will be useful to the fresh-cut fruit industry for developing methods to improve the shelf life of cut fruits.
Technical Abstract: Lipase enzyme in fresh-cut cantaloupe melon (Cucumis melo L. var. reticulatus Naud) was assayed and the effects of storage at 4 and 15 oC on enzymatic activity were determined. The enzyme was stable for 24 h at both temperatures, but decreased by 45% after 120 h storage time at 15 oC. Isoelectric studies suggest a possible dual lipase and esterase action of the enzyme. Enzymatic activity increased by about 60% when the reaction temperature was increased from 30 to 40 oC and remained constant until 70 oC, but the enzyme was unstable when stored at the high temperature. Calcium treatment reduced lipase activity in the fresh cut fruit.