半乳糖醛酸酯酶的活性对芒果硬度的影响

Influence of PG Activities to Mango Degree of Hardness

以新摘大台农芒果为原料,对其采后采取不同贮藏处理方式,对贮藏期间芒果的硬度、多聚半乳糖醛酸酶(PG)的活性和果胶含量的变化进行了研究。结果表明,在贮藏过程中,PG活性提高,导致原果胶水解为可溶性果胶,原果胶平均含量从贮藏初期的1.721%下降到最后的0.9982%,而可溶性果胶从0.1076%上升到0.9452%,总果胶含量也稍微呈上升趋势,从1.8342%上升到1.8969%;PG酶活性先上升至最高点,然后稍微有所下降,从11.34个酶单位增大到17.10个酶单位后又回落到16.03个酶单位,芒果硬度从0.234kg/cm下降为0.162kg/cm,果22实发生了软化。以不经过任何处理的芒果为空白对照,比较了5种不同涂膜保鲜方法的效果,并且从这些保鲜方法中,筛选出较好的保鲜方法是涂130mg/kg甲基托不津+1.3%壳聚糖+90%甘油,贮藏期可延长7d。

The changes of degree of hardness, polygalacturonase （PG） actives and pectin content of new picked Mango （Da Tai Nong） which were after there adoptions by the different storages approach clones during the storage were studied. The resuits showed that during the storage, the activity of PG increased markedly and the insoluble pectin was changed into soluble pectin. The result is that the insoluble pectin content was decreased from 1.721% in the early days of the storage to 0.998 2% in the end and the soluble pectin content was increased from 0.107 6% to 0.945 2% on average. Total pectin content also slightly upward trend, rose to 1.896 9% from 1.834 2%. At the same time, PG actives Srst rose to the highest point, and then declined slightly, from 11.34 to 17.10 enzyme units, and then subsequently fallen to 16.03 enzyme units. The fruit firmness was declined from 0.234 kg/cm^2 to 0.162 kg/cm^2. Fruits were become soften. To deal with without anything in the mango to compare the effects of five different preservation methods, a very good method was filtrated from those different preserving methods, which was 130 ppmjhiophanate -methyl＋ 1.3%chitosan ＋ 90%glycerine. The storage period may be extended 7days.