对凉茶中的腐败菌进行分离鉴定得出其中腐败菌主要为革兰氏阳性芽孢杆菌（多粘芽孢杆菌、短小芽孢杆菌、巨大芽孢杆菌），通过对腐败菌的抑菌剂进行筛选和优化得出乳酸链球菌素（Nisin）、尼泊金复合酯、壳聚糖3种对腐败菌有明显的抑制作用的抑菌剂。利用响应面方法对三种抑菌剂复合后的抑菌效果进行优化，应用Box-Behnken试验设计，建立3种抑菌剂的二次多项式回归方程模型进行分析得出最佳复合抑菌剂配方，并对获得配方的抑菌效果进行验证，以检验响应面法的可靠性。

Separation and identification of spoilage bacteria from herbal tea showed that the main spoilage organisms in the herbal tea were Gram-positive Bacillus bacteria (Paenibacillus polymyxa,Bacillus pumilus and Bacillus megaterium). The better preservative for inhibition of the spoilage bacteria in herbal tea were found as Nisin, Nipagin ester and Chitosan. The formulation of a compound preservative with the three preservatives for enhanced efficacy was optimized by response surface methodology. A quadratic polynomial regression model was built using Box-Behnken design, The best composite bacteriostatic agent formula and the antibacterial effects of preservatives combination were validated.