Antimicrobial activity of microcapsules with aqueous extract of chambá (Justicia pectoralis Jacq)

ABSTRACT To ensure the antimicrobial activity of the aqueous extract of chambá, it is essential to protect its bioactive compounds. The objective was to preserve its characteristics, aiming to provide the food industry with a natural antimicrobial. Three microcapsule formulations made with maltodextrin and cyclodextrin were developed, both including the aqueous extract of chambá leaves dried through lyophilization. The aqueous extract was initially submitted to in vivo toxicity analysis using zebrafish and the microcapsules were characterized through studies of morphology, hygroscopicity, water solubility, particle size, zeta potential, color determination, microencapsulation efficiency and antimicrobial activity. The aqueous extract of chambá was not considered to be toxic. The microcapsules had irregular shapes, with sizes varying from 0.58 to 1.15 µm. Solubility values ranged from 74.69 to 76.8% and hygroscopicity varied from 2.07 to 4.34%. Additionally, it obtained efficient encapsulation of the phenolic compounds, showing antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli, with its use being an alternative as a natural antimicrobial agent.

摘要 为保障chambá叶水提物的抗菌活性，对其生物活性成分进行保护至关重要。本研究旨在保留该提取物的固有特性，以期为食品工业提供一类天然抗菌制剂。研究开发了三种以麦芽糊精与环糊精为壁材的微胶囊配方，所有配方均包含经冷冻干燥处理的chambá叶水提物。首先通过斑马鱼模型开展该水提物的体内毒性分析，随后通过形态学、吸湿性、水溶性、粒径、Zeta电位、色度测定、微胶囊包封率及抗菌活性等多项表征指标对所制备的微胶囊进行系统性分析。结果表明，chambá叶水提物无明显毒性。所制备的微胶囊形态不规则，粒径范围为0.58 μm至1.15 μm；溶解度介于74.69%至76.8%，吸湿性为2.07%至4.34%。此外，该微胶囊可高效包封酚类化合物，对金黄色葡萄球菌（Staphylococcus aureus）、单核细胞增生李斯特菌（Listeria monocytogenes）、肠炎沙门氏菌（Salmonella Enteritidis）以及大肠杆菌（Escherichia coli）均表现出抗菌活性，可作为天然抗菌剂的替代方案加以应用。