黑曲霉Pectinex XXL菌株产果胶酶的酶学特性及其在果汁生产中的应用

Enzymatic Characterization of Pectinex XXL, a Pectinase Produced by Aspergillus niger, and Its Application in Fruit Juice Production

摘要:

该研究旨在探讨商业果胶酶制剂Pectinex XXL的酶学性质及其在果汁工业生产中的应用潜力。该实验以聚半乳糖醛酸为底物，使用DNS法对Pectinex XXL的酶学特性进行了表征，结果表明：其最适pH值为4.5，且在pH值3.0~4.5稳定。该酶最适pH值和pH稳定范围与一些热带和亚热带水果的pH值一致。其最适温度为60 ℃,且在40 ℃水浴1 h后保持稳定。此外该酶活性不受1 mmol/L Na+、Mg2+、Ba2+、Co2+、Zn2+、Fe2+抑制，受2 mmol/L K+和Fe2+轻微抑制，受1 mmol/L和2 mmol/L Ca2+和Mn2+部分抑制，证明其具有良好的酸稳定性和热催化特性。在以上实验基础上探讨不同酶量对芭蕉果汁和圣女果汁进行脱胶实验，反应1 h，该酶（16 U/mL）能显著提高芭蕉果汁和圣女果汁的产量和透光率，分别为119.03%、15.97%和37.65%、12.35%，并使芭蕉果汁和圣女果汁粘度分别下降88.29%和29.50%。果汁生产实验证明，该酶能显著提高芭蕉果汁出汁率和透光率，并能有效降低芭蕉果汁粘度。因此Pectinex XXL在芭蕉果汁工业生产中具有应有潜力。

Abstract:

Pectinex XXL, a commercially prepared pectinase, was investigated for its potential application in the fruit juice industry. Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pectinex XXL using the DNS method. According to the results, the optimal pH for Pectinex XXL activity was 4.5, and the enzyme was stable in the pH range of 3.0~4.5. The optimal pH and pH stability range are consistent with those of some tropical and subtropical fruits. The optimal temperature for Pectinex XXL activity was 60 ℃, and the enzyme remained stable after one hour in a water bath set at 40 ℃. Additionally, the enzymatic activity was not inhibited in the presence of 1 mmol/L of Na+, Mg2+, Ba2+, Co2+, Zn2+, and Fe2+, whereas it was slightly inhibited in the presence of 2 mmol/L of K+ and Fe2+ and partially inhibited in the presence of 1 and 2 mmol/L of Ca2+ and Mn2+, demonstrating its good stability in acids and excellent thermal catalytic performance. Based on the above experimental results, depectinization experiments were performed on plantain and cherry tomato juices using different amounts of Pectinex XXL. After one hour reaction with 16 U/mL of the enzyme, the yields of the plantain and cherry tomato juices were substantially increased by 119.03% and 15.97%, respectively, while their light transmittance was remarkably enhanced by 37.65% and 12.35%, respectively. Furthermore, the enzyme reduced the viscosity of the plantain and cherry tomato juices by 88.29% and 29.50%, respectively. The juice production experiments confirmed that this enzyme can significantly improve the yield and light transmittance of plantain juice, while effectively reducing its viscosity. These findings indicate the potential of Pectinex XXL in the industrial production of plantain juice.