速冻方式对番木瓜浆功能酶活力冻藏稳定性的影响

Effects of Different Quick-Freezing Methods on the Stability of Enzymes in Frozen Papaya Pulp

以鲜榨番木瓜浆为材料,研究不同速冻方式对番木瓜浆的功能酶活力冻藏稳定性的影响。采用-40℃液浸式速冻机和-40℃超低温冰箱对比,分别测定其冻结曲线,分析液浸式速冻和空气对流冻结对番木瓜浆-18℃冻藏过程中木瓜蛋白酶、木瓜凝乳酶、脂肪酶比活力的变化。结果表明:采用-40℃液浸式速冻的番木瓜浆中心温度通过最大冰晶生成区的速度比-40℃空气对流冻结方式快8.2倍,冻结速度对冻藏期间番木瓜浆中功能酶活力的保持有显著影响;番木瓜浆采用液浸式速冻,-18℃冻藏90d,能较好保持功能酶活力。

Fresh papaya pulp was quick-frozen by liquid immersion freezing or in an ultra-low temperature freezer both at -40 ℃ to evaluate the effects of the quick-freezing methods on the stability of enzymes in frozen papaya pulp. The corresponding freezing curves were plotted. Meanwhile, changes in the activities of papain, chymopapain and lipase in papaya pulp quick-frozen by the two methods were analyzed during storage at -18 ℃. The results showed that the internal temperature of papaya pulp quick-frozen by liquid immersion freezing passed through the zone of maximum ice crystal formation 8.2 times than that observed with air convection freezing. The quick-freezing rate significantly affected preservation of enzyme activities in papaya pulp during frozen storage. The investigated enzyme activities in liquid immersion frozen papaya pulp were retained well for 90 d at -18 ℃.