连翘叶发酵型饮料的研制及抗氧化活性研究

以连翘叶、白砂糖、阿拉伯胶为主要原料，制备连翘叶发酵型饮料。在单因素试验基础上，以感官评分为评价指标，采用二次通用旋转组合试验优化其发酵工艺，并考察其对1,1-二苯基-2-三硝基苯肼(DPPH)、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)自由基清除能力及还原力。结果表明，连翘叶发酵型饮料的最佳发酵工艺条件为白砂糖添加量5%，复合菌种(克鲁维毕赤酵母∶植物乳杆菌=1∶1)接种量0.04%，连翘叶粉添加量2.0%，阿拉伯胶添加量0.6%，发酵时间18 h。在此优化条件下，连翘叶发酵型饮料感官评分为(86.53±1.03)分，色香味俱佳，口感酸甜，无明显苦味，理化与微生物指标均符合相关国家标准。连翘叶发酵型饮料的DPPH自由基清除率、ABTS自由基清除率及还原力(OD_{700 nm}值)分别为(90.57±2.63)%、(79.85±1.74)%、(0.736±0.04)，表明其具有良好的抗氧化性。

Development and antioxidant activity of fermented Forsythia suspensa leaves beverage

Fermented Forsythia suspensa leaves beverage was prepared using F. suspensa leaves, sugar and acacia gum as raw materials. On the basis of single factor test, using sensory score as evaluation index, the fermentation process was optimized by second universal rotating combination experiments, and the free radical scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and reducing power were investigated. The results showed that the optimal fermentation conditions of the beverage were as follows: sugar addition 5%, mixed strains (Pichia kluveri ∶ Lactobacillus plantarum=1∶1) inoculum 0.04%, F. suspensa leaves powder addition 2.0%, acacia gum addition 0.6%, and fermentation time 18 h. Under these optimized conditions, the sensory score of fermented F. suspensa leaves beverage was (86.53±1.03), which was good in color, flavor, sour and sweet taste, and without obvious bitterness. The physicochemical and microbial indexes were in line with relevant national standards. The DPPH free radical clearance rate, ABTS free radical clearance rate and reducing power (OD700 nm value) of the beverage were (90.57±2.63)%, (79.85±1.74)% and (0.736±0.04), respectively, indicating it had good antioxidant activity.