不同添加物对菠萝蛋白酶酶活稳定性和抑制作用的影响

Effects of Different Additives on the Activity and Stability of Bromelain

选择几种添加物于菠萝蛋白酶酶液中,并在不同pH值缓冲液中保存,定期测定其酶活力,研究添加物及缓冲液对菠萝蛋白酶的稳定性和抑制作用的影响。结果显示:VB1、L-半胱氨酸、异抗坏血酸钠、NaCl对菠萝蛋白酶酶活均有促进作用。保存的第1天,添加0.100g/100mL VB1的酶活比对照组提高了22%。添加0.2g/100mLL-半胱氨酸、0.005g/100mL异抗坏血酸钠的酶活比对照组分别提高了60%、37%。而NaNO2、乙酸锌、ZnCl2对菠萝蛋白酶酶活都有一定的抑制作用。随着NaNO2浓度的升高,抑制作用逐渐增强。乙酸锌、ZnCl2能将菠萝蛋白酶酶活分别降低到原酶活力的11%、1%。而KCl和NaNO3对菠萝蛋白酶活力影响不显著。

In order to find out the stability of bromelaln in different medium environments, the activity of bromelain stored at 4 ℃ in the presence of VBI, L-cysteine, sodium ascorbate or NaCl at varying concentrations was assayed at regular intervals of time. In addition, the effects of several salts commonly used to cure meat such as KCl, NaNO2 and NaNO3, Zn^2＋ and different types of buffer solutions with different pH values on the activity of the enzyme were explored. VBI, L-cysteine, sodium ascorbate and NaCl had an activating effect on the activity of bromelain. After 1 d of storage, the activity of 0. 1 g/100 mL VBI group was increased by 22% when compared to control group （with nothing added）, and 0.2 g/100 mL L-cysteine group and 0.005 g/100 mL sodium ascorbate group exhibited an increase of respectively 60% and 37%. The activity of the enzyme was obviously inhibited by NaNO2, NaNO3, zinc acetate and ZnCl2. The inhibitory effect of NaNO2 showed a gradually upward trend as the concentration increased. In the presence of zinc acetate and ZnCh under the concentrations studied, the enzyme retained 11% and 1% of its original activity, respectively at least. However, neither KCl nor NaNO3 had a marked effect on the activity of the enzyme.