Laboratório de Microbiologia e Higiene de Alimentos, Departamento de Ciência de Alimentos, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil; Laboratório de Bioquímica e Microbiologia Aplicada, Departamento de Ciência de Alimentos, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil.
Laboratório de Microbiologia e Higiene de Alimentos, Departamento de Ciência de Alimentos, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, Brazil.
Food Microbiol. 2022 Dec;108:104116. doi: 10.1016/j.fm.2022.104116. Epub 2022 Aug 18.
Carvacrol is a natural antimicrobial with excellent antimicrobial properties against several foodborne pathogens. Encapsulation can increase carvacrol stability and solubility, and mask its pronounced odor. Mucilages have been studied as wall material for nanoparticles due to their high retention capacity of bioactive compounds and ease of chemical modifications to improve their stability. In this study, 1.67 mg/mL of carvacrol encapsulated into chia mucilage nanoparticles (CMNP) and flaxseed mucilage nanoparticles (FMNP) were produced by high-energy emulsification technique and tested against Listeria monocytogenes and Salmonella. Encapsulation efficiency around 98% of carvacrol was obtained for both formulations. CMNP showed a diameter size of 179 nm and zeta potential of -11.4 mV. Bacterial Inactivation Concentration (BIC) of CMNP was 0.42 mg/mL against Salmonella and 0.83 mg/mL against L. monocytogenes. FMNP showed diameter size of 165.3 nm and zeta potential of -12.6 mV. BIC of FMNP was 0.83 mg/mL against both microorganisms. Scanning electron microscopy analysis showed that the nanoparticles are spherically shaped. Concentrations of BIC and ½ BIC were used to evaluate the kinetics of bacterial growth in the presence of antimicrobials (CMNP, FMNP and carvacrol solution). The results of this test showed that viable counts of Salmonella and L.monocytogenes were below the detection limit (1.69 log CFU/mL) after 2 h incubation (37 °C) using CMNP at the BIC. The wall material, rehydrated chia and flaxseed mucilages, reduced L. monocytogenes growth during 24 h. However, unloaded nanoparticles kept the viable counts of both microorganisms 2-5 log CFU/mL below the control curve of microbial growth during the 48 h experiment, suggesting that nanostructured mucilages potentiate antimicrobial properties. The results indicate that CMNP and FMNP have potential for use as food preservatives.
香芹酚是一种天然的抗菌剂，对多种食源性病原体具有优异的抗菌性能。包封可以提高香芹酚的稳定性和溶解度，并掩盖其强烈的气味。由于具有高保留生物活性化合物的能力和易于进行化学修饰以提高其稳定性，因此糊精已被研究作为纳米粒子的壁材料。在这项研究中，通过高能乳化技术制备了 1.67mg/mL 的香芹酚包封到奇亚胶纳米粒子（CMNP）和亚麻胶纳米粒子（FMNP）中，并对单核细胞增生李斯特菌和沙门氏菌进行了测试。两种配方的香芹酚包封效率均接近 98%。CMNP 的粒径为 179nm，zeta 电位为-11.4mV。CMNP 对沙门氏菌的细菌失活浓度（BIC）为 0.42mg/mL，对单核细胞增生李斯特菌的 BIC 为 0.83mg/mL。FMNP 的粒径为 165.3nm，zeta 电位为-12.6mV。FMNP 对两种微生物的 BIC 均为 0.83mg/mL。扫描电子显微镜分析表明，纳米粒子呈球形。使用 BIC 和半 BIC 浓度评估了抗菌剂（CMNP、FMNP 和香芹酚溶液）存在下细菌生长的动力学。该测试的结果表明，在用 BIC 的 CMNP 孵育 2 小时（37°C）后，沙门氏菌和单核细胞增生李斯特菌的活菌数低于检测限（1.69logCFU/mL）。在 24 小时内，再水化的奇亚和亚麻胶降低了单核细胞增生李斯特菌的生长。然而，未加载的纳米粒子在 48 小时的实验中使两种微生物的活菌数保持在低于微生物生长对照曲线 2-5logCFU/mL，表明纳米结构化糊精增强了抗菌性能。结果表明，CMNP 和 FMNP 具有作为食品防腐剂的潜力。
