Centro de Nanociência e Nanotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Laboratório de Cereais, Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Int J Food Microbiol. 2019 Mar 16;293:72-78. doi: 10.1016/j.ijfoodmicro.2019.01.006. Epub 2019 Jan 12.
Liposomes have gained great interest in the food and pharmaceutical industry as colloidal carriers of bioactive compounds. In this work, liposomes of phosphatidylcholine (PC) and oleic acid (OA) encapsulating garlic extract (GE) were developed to determine its aptitude as antifungal agent in wheat bread. The influence of GE on the properties of liposomes were followed by determination of size, Zeta potential, Fourier transform infrared patterns (FTIR), morphology, differential scanning calorimetry (DSC) and thermogravimetric (TGA) techniques. The produced PC-OA-GE liposomes showed spherical morphology with narrow size distribution, entrapment efficiency of 79.7% and zeta potential of -27.9 mV. In vitro antifungal test showed noticeable inhibitory activities for free and encapsulated GE against selected fungal strains. TGA analysis revealed that the presence of OA and GE in the formulation retards the liposomal thermal decomposition, as compared with the pure PC liposomes and the DSC enthalpy and main transition temperature variation in PC-OA-GE liposomes suggested a strong heat-induced rigidifying effect that could be attributed to the presence of garlic polysaccharides in the liposome surface, observed by FTIR. In the in situ test, the bread formulations with free or liposome-encapsulated GE (0.65 mL/100 g of dough) were microbiologically more stable as compared with the controls, showing mold inhibition for five days. Therefore, liposomes formulated with OA and GE showed potential as natural antifungal agent in bakery products.
脂质体作为生物活性化合物的胶体载体，在食品和制药行业引起了极大的兴趣。在这项工作中，开发了含有大蒜提取物（GE）的磷脂酰胆碱（PC）和油酸（OA）的脂质体，以确定其作为小麦面包中抗真菌剂的潜力。通过测定粒径、Zeta 电位、傅里叶变换红外图谱（FTIR）、形态、差示扫描量热法（DSC）和热重分析（TGA）等技术，研究了 GE 对脂质体性质的影响。所制备的 PC-OA-GE 脂质体呈球形，粒径分布较窄，包封效率为 79.7%，Zeta 电位为-27.9mV。体外抗真菌试验表明，游离和包封的 GE 对所选真菌菌株均具有显著的抑制活性。TGA 分析表明，与纯 PC 脂质体相比，OA 和 GE 的存在延缓了脂质体的热分解，而 PC-OA-GE 脂质体的 DSC 焓和主转变温度的变化表明，由于在脂质体表面存在大蒜多糖，因此存在强烈的热诱导刚性化效应。在原位试验中，与对照相比，含游离或脂质体包封 GE（0.65mL/100g 面团）的面包配方在微生物方面更稳定，可抑制霉菌生长达五天。因此，含有 OA 和 GE 的脂质体作为天然抗真菌剂在烘焙产品中具有潜力。
