EFFECT OF UHP ON ENZYME, MICROORGANISM AND FLAVOR IN CANTALOUPE (CUCUMIS MELO L.) JUICE

In this study, we investigated the change of the flavor, enzyme activities and microorganism survival in cantaloupe (Cucumis melo L.) juice after UHP treatments, and found the corresponding kinetic models. After the treatment at 500 MPa for 20 min, the pressurized juice can reach the safety standards, i.e., below 100 cfu/100 mL in concentration stipulated for beverage by Chinese national standard; and the activities of POD, PPO and LOX in the juice decreased to about 78, 9 and 5%, respectively. Sensory evaluation indicated that no significant change was observed after UHP treatments. The above findings indicated that UHP treatment is a promising way to process the cantaloupe juice. PRACTICAL APPLICATION Cantaloupe is a favorable fruit with unique aroma produced around the world. However, because there is no effective deep-processing, a lot of cantaloupes rot away in the farmland every year. The production of freshly squashed juice is a best way to raise the merchandise rate of cantaloupe and to prolong its industrial chain. However, freshly squashed cantaloupe juice has a very short shelf life because it will quickly succumb to microorganism attack if nothing is done. The sterilization of its juice is a difficult issue because the juice is heat sensitive. Therefore, nonthermal processing is desirable. UHP technology used in this study was proven to be a promising way to maintain the flavor and to inactivate enzymes and microorganisms in the cantaloupe juice.