乳酸菌发酵黄芪的风味及活性成分分析

Analysis of flavor and active components of Astragalus fermented by lactic acid bacteria

中文关键词:  乳酸菌  黄芪  发酵  风味  活性成分

英文关键词:lactic acid bacteria  Astragalus  fermentation  flavor  active component

中文摘要:

      目的 采用3种不同乳酸菌对黄芪进行固态发酵, 并对发酵黄芪的活性成分、抗氧化性、风味物质和微观结构进行分析。方法 采用副干酪乳杆菌、短双歧乳杆菌和植物乳杆菌对黄芪固态发酵6 d, 测定其活性成分含量(总酚和总黄酮)和抗氧化性{1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl, DPPH)、2,2’-联氮-双(3-乙基苯并噻唑啉-6-磺酸)阳离子[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation, ABTS+]、羟(hydroxyl, OH)自由基清除率和总还原力)}, 利用电子鼻、气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)和气相色谱-离子迁移谱法(gas chromatography-ion mobility spectrometry, GC-IMS)进行风味分析, 并通过扫描电子显微镜观察微观结构。结果 植物乳杆菌发酵黄芪(HB-MR)总酚和总黄酮含量最高, 分别达到1.02 mg GAE/g和13.69 mg RE/g; HB-MR抗氧化能力最高, DPPH、ABTS+、OH自由基清除率和总还原力分别达到74.44%、65.60%、67.49%和0.54; 不同乳酸菌发酵后降低了黄芪原有的刺激性气味, 但具有不同的挥发性风味特征, 其中HB-MR中增加了酯类、酸类、烃类含量, 丰富了椰子香味; 同时乳酸菌发酵后黄芪表面附着颗粒物质明显减少, 结构紧密。结论 乳酸菌发酵黄芪提高了其活性成分含量和抗氧化能力, 减少了黄芪原有的刺激性风味, 为以后产品开发提供了有益菌种和技术支撑, 也为后续探索复合菌剂研发积累了数据。

英文摘要:

      Objective To analyze the active components, antioxidant activities, flavor compounds, and microstructure of Astragalus fermented by 3 kinds of different lactic acid bacteria. Methods Astragalus was solid-state fermented for 6 d using Lactobacillus paracasei, Bifidobacterium breve, and Lactobacillus plantarum. The content of active components including total phenols and total flavonoids, as well as antioxidant activities including 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS+), hydroxyl (OH) free radical scavenging rates and total reducing power was determined. The flavor analysis was conducted using electronic nose, gas chromatography-mass spectrometry (GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS). In addition, the microstructure was observed by scanning electron microscopy. Results Lactobacillus plantarum fermented Astragalus (HB-MR) showed the highest content of total phenols and flavonoids, reaching 1.02 mg GAE/g and 13.69 mg RE/g, respectively. HB-MR also demonstrated the highest antioxidant capacity, with DPPH, ABTS+, OH free radical scavenging rates and total reducing power reaching 74.44%, 65.60%, 67.49% and 0.54, respectively. Different lactic acid bacteria fermentation reduced the original stimulating odor of Astragalus, with producing distinct volatile flavor characteristics. HB-MR increased the content of esters, acids, and hydrocarbons, enriching the coconut aroma. Additionally, the amounts of absorbed particles on Astragalus surface were obviously reduced with compact microstructure after lactic acid bacteria fermentation. Conclusion Lactic acid bacteria fermentation enhances the active component content and antioxidant capacity of Astragalus, and reduces its original stimulating flavor. This provides beneficial bacterial strains and technical support for future product development, and accumulates data for subsequent research on compound microbial agents.