Aim of this work was to evaluate the antimicrobial activity and physical characteristics of citral microencapsulated with dextrin (Dx) by spray drying. The encapsulation was optimized using response surface methodology (RSM), maximizing yield and efficiency, considering as independent variables the citral:Dx ratio (1:5 and 1:20) and the inlet air temperature (120 and 200 °C). Yield and efficiency under optimal conditions were 71.9% and 99.9%, respectively. Antimicrobial activity against Escherichia coli, Salmonella enterica, Staphylococcus aureus and Bacillus cereus of the citral microparticles obtained under optimal conditions and of free citral was evaluated using the disk diffusion methodology. Both compounds showed a broad spectrum inhibitory effect, being Escherichia coli and Bacillus cereus the most sensitive microorganisms. The inhibition ratio varied between 55 and 75%, and the antibacterial activity was maintained after microencapsulation. The minimum inhibitory concentrations of free citral were above 0.8 mg/mL. The optimal citral microparticles showed acceptable physicochemical characteristics and broad-spectrum antimicrobial activity. Polymer and emulsifier used in microencapsulation protected the functional activity of citral, thus suggesting that these microparticles could be used in the design of antimicrobial food systems to extend the shelf life of perishable foods.

这项工作的目的是通过喷雾干燥评估糊精（Dx）微囊化的柠檬醛的抗菌活性和物理特性。使用响应表面方法（RSM）优化封装，最大程度地提高产量和效率，将柠檬醛：Dx比率（1：5和1:20）和进气温度（120和200°C）作为独立变量。在最佳条件下的产率和效率分别为71.9％和99.9％。对大肠杆菌，肠炎沙门氏菌，金黄色葡萄球菌和蜡状芽孢杆菌的抗菌活性使用圆盘扩散法评估了在最佳条件下获得的柠檬醛微粒的含量和游离柠檬醛的含量。两种化合物均表现出广谱抑制作用，分别是大肠杆菌和蜡状芽孢杆菌最敏感的微生物。抑制率在55％到75％之间变化，微囊化后保持了抗菌活性。游离柠檬醛的最低抑制浓度高于0.8 mg / mL。最佳柠檬醛微粒表现出可接受的理化特性和广谱抗菌活性。微囊化中使用的聚合物和乳化剂保护了柠檬醛的功能活性，因此表明这些微粒可用于抗微生物食品系统的设计中，以延长易腐食品的保质期。