微波、酶法双辅助提取葡萄籽原花青素及其抑菌性研究

Microwave and Enzyme-assisted Extraction of Grape Seed Procyanidins and Study of Their Antibacterial Activity

摘要:

本文以新疆白葡萄籽为研究对象，利用微波、酶法双辅助提取葡萄籽中原花青素，并研究其抑菌性。在单因素实验的基础上，利用Box-Behnken原理设计响应面实验，研究了料液比、微波时间、微波温度及纤维素酶添加量4个因素对葡萄籽原花青素提取率的影响，经过AB-8型大孔树脂纯化后，得到的原花青素纯度为95.6%，探究其抑菌性。实验表明，在微波温度60 ℃、料液比1:14.6 (g:mL)、微波时间9 min、纤维素酶添加量量0.56 mg/mL的条件下，得到的原花青素提取率最大为5.72%。经纯化后的原花青素能有效抑制金黄色葡萄球菌，抑菌圈直径达19.2 mm，最低抑菌浓度（MIC）为2.5 mg/mL，最低杀菌浓度（MBC）为5 mg/mL。经原花青素作用后的细菌，细胞膜通透性增加，细胞壁遭到破坏，扫描电镜照片显示细菌细胞表面凹陷褶皱，细胞大小不一。

Abstract:

Procyanidins of Xinjiang white grape seeds were extracted by microwave and enzyme-assisted treatments for study of their antibacterial activity. Response surface analysis was conducted, using the Box-Behnken design experiment based on the single-factor test, to investigate the influence of four main factors (solid-liquid ratio, microwave time, microwave temperature, and cellulose dosage) on the procyanidin extraction rate. The extracted procyanidin sample was purified (purity 95.6%) using AB-8 macroporous resins. The optimal extraction conditions were as follows: temperature, 60 ℃; solid-liquid ratio, 1:14.6 (g:mL); microwave time, 9 min; and cellulose dosage, 0.56 mg/mL. Under these conditions, the procyanidin extraction yield was 5.72%. The purified procyanidins could effectively inhibit the growth of Staphylococcus aureus, with an inhibition zone diameter of 19.2 mm, a minimal inhibitory concentration (MIC) of 2.5 mg/mL, and a minimum bactericidal concentration (MBC) of 5 mg/mL. After treatment with the procyanidins, the permeability of the bacterial cell membrane was increased and the cell wall was destroyed. Scanning electron microscope images of the procyanidin-treated S. aureus showed wrinked bacterial surfaces and different cell sizes .