热处理条件对蓝莓汁中花色苷和加工特性的影响

Effect of Heating Treatment on the Anthocyanins Contents and Processing Properties of Blueberry Juice

为研究热处理条件对蓝莓汁生产过程中出现的色泽和功能成分改变的影响,采用沸水热烫和微波加热两种方法对蓝莓进行处理,测定果汁中多酚氧化酶（PPO）活性、主要功能性成分花色苷和总酚等含量,以及果汁色泽的变化。热烫处理0-2 min内,PPO的残余活力迅速下降,花色苷含量没有显著变化,果汁颜色变暗,红色减弱,蓝色增强;低频率微波处理,不能起到钝化PPO的效果,而高微波功率作用又对花色苷造成很大的破坏,使得蓝莓中多酚氧化酶的活性增加,之后随着微波频率的进一步增加,PPO的酶活力迅速下降。在实际生产中,应结合低功率微波和短时热烫处理,同时保留蓝莓汁功能成分和维持色泽。

In order to study the effect of heating treatment on the change of color and functional components in the processing of blueberry juice, two methods, water boiling and microwave heating, were used in this paper. The residue activity of polyphenol oxidase（PPO）, the content of anthocyanins and total phenols, and the color change were monitored in the study. During the first 2 min in the boiling water, the activity of PPO decreased rapidly, while the content of anthocyanins had no significant change. Consequently, the juice color became dark, with the red color decreased and blue increased. When heated by low-power microwaving, PPO in the juice didn＇t inactivated, while high-power microwaving caused great destroy of anthocyanins and increase of PPO activity. As the increase of the microwave power,PPO activity decreased rapidly. Hence, water boiling in the short time, combined with low-power microwaving, is suggested in the industry, to keep the functional components and color stable.