研究了菠萝各器官的蛋白酶含量、活性和提取过程中酶活性的保护作用，结果表明，“无刺卡因”品种的青果、７０％成熟果肉、７０％成熟果皮、茎、果柄、叶的粗酶含量分别为０．３５９、０．１９４、０．１３２、０．９９４、０．３０３和０．１９５％。各器官酶活性以青果酶活性最高。在提取过程中使用乙二胺四乙酸二钠、醋酸锌、氯化钠、抗坏血酸可使果肉蛋白酶、茎蛋白酶和叶蛋白酶活性分别提高６９．３７％、９３．８８％和１３９．６９％。１０００ｐｐｍ硫代硫酸钠＋１０００ｐｐｍ半胱氨酸是菠萝蛋白酶活性的有效保护剂，可使果蛋白酶和茎蛋白酶活性分别提高３５．５１％和６９．０６％。

The contents and the activities of bromelin in organs of pineapple, and the protection of enzyme activities during extracting process were investigated. It was indicated that the contents of bromelin in green fruit, fruit pulp and skin of 70% ripeness, stem, stalk and leaf of "Wucikayin" cultivar were 0. 359, 0. 194, 0. 132, 0. 994, 0. 303, and 0. 195% respectively. The activity of bromelin in green fruit was the highest among all those of organs. The use of disodiurn EDTA, zinc acetate, sodium chloride and ascorbic acid in the extracting process could raise the activities of brornelin in fruit pulp , stem and leaf by 69. 37%, 93. 88% and 139. 69% respectively. It was discovered that 1 000 ppm of sodium hyposulfate plus 1 000 ppm of cysteine was an effective protector of enzyme activity and raised the activities of fruit bromelin and stem bromelin by 35. 51% and 69. 06%.