微胶囊化生姜、枸杞、栀子提取物的ACE抑制率、苦味及稳定性研究

本文通过粉碎、超声获得生姜、枸杞、栀子的混合醇提物，以麦芽糊精、变性淀粉、两者混合分别与明胶作为复合包埋壁材，利用喷雾干燥制成微胶囊，测定其包埋率、ACE（angiotensin-convertion enzyme）抑制率、吸湿性、总酚含量（TPC）、苦味程度，并利用红外光谱（FTIR）、扫描电镜（SEM）、热重分析仪（TGA）对微胶囊化颗粒的结构、热稳定性进行研究。结果表明，微胶囊的最佳壁材为麦芽糊精和变性淀粉质量比1:1混合，此时包埋率为75.24%（P<0.05），红外光谱分析表明，提取物被壁材包埋成功并形成了淀粉/糊精-酚类-明胶聚合体。与未包埋及单一麦芽糊精、变性淀粉包埋相比，以麦芽糊精和变性淀粉质量比1:1混合作为壁材包埋后的微胶囊苦味显著（P<0.05）降低，吸湿性由未包埋时的52.83 g/(100 g)降为16.04 g/(100 g)。该微胶囊经胃肠消化后其中的酚类释放率为69.64%，ACE抑制率为49.64%（P<0.05）。由此可见，以麦芽糊精和变性淀粉质量比1:1混合作为壁材的微胶囊化药食同源提取物，能明显降低苦味并提高产品稳定性，在室温保存7 d后，ACE抑制率仍高达22.36%。

ACE Inhibitory Rate,Bitterness and Stability of Microencapsulated Extracts of Ginger,Chinese Wolfberry and Gardenia jasminoides

This study obtained mixed alcohol extracts of ginger, Chinese wolfberry, and Gardenia jasminoides by pulverization and ultrasound. Maltodextrin, modified starch, and a mixture of both with gelatin as the composite embedding wall material, and spray dried into microcapsules. The embedding rate, ACE(angiotensin-convertion enzyme) inhibition rate, hygroscopicity, total phenol content(TPC), bitterness degree were determined, and infrared spectroscopy(FTIR), scanning electron microscope(SEM), thermogravimetric analyzer(TGA) were used to study the structure and thermal stability of microencapsulated particles. The results showed that the best wall material of the microcapsules was a 1:1 mixture of maltodextrin and modified starch. At this time, the embedding rate was 75.24%(P<0.05). The infrared spectrum analysis showed that the extract was successfully embedded by the wall material, and forming a starch/dextrin-phenol-gelatin polymers. Compared with non-embedded and single maltodextrin, modified starch embedding, the bitterness of the microcapsules embedded with a 1:1 mixture of maltodextrin and modified starch as the wall material was significantly reduced(P<0.05), and the hygroscopicity was reduced from 52.83 to 16.04 g/(100 g). The release rate of phenols in the microcapsules after gastrointestinal digestion was 69.64%, and the ACE inhibition rate was 49.64%(P<0.05). Thus, modified starch and maltodextrin in weight ratio 1:1 mixing, as the microencapsulated medicinal and food homologous extract of the wall material, could significantly reduce bitterness and improve product stability. After storage at room temperature for seven days, the ACE inhibition rate was still as high as 22.36%.