Citral encapsulation was analyzed by spray and freeze-drying to obtain an antimicrobial additive in powder. Different formulations containing alginate and modified starch (Capsul®) as encapsulating agents (1% and 3% w/w, respectively) and maltodextrin as a wall material at different concentrations (varied from 1:1–1:4 Citral:Maltodextrin) were prepared. The powders were evaluated for physical and antimicrobial properties against Escherichia coli to obtain a natural antimicrobial food additive. Citral:Capsul:Maltodextrin powders obtained by spray-drying showed the best physical properties, considering encapsulation yield (EY) (75%–80%), encapsulation efficiency (EE) (~78%), and particle size (5–10 μm), and a higher microbial inhibition at a lower additive concentration (1.5%–2% w/w), independently of maltodextrin concentration used. Powders obtained by freeze-drying emulsions showed an EY ~70%, EE ~70%, particle sizes between 80 and 1250 μm, and a higher percentage of rehydration for antimicrobial activity (2.5%–4% w/w). An increase in maltodextrin concentration led to a decrease in %EE, an increase in particle size, and the powder concentration required to inhibit microbial growth. Therefore, the formulation 1:1:1 Citral:Capsul:Maltodextrin showed by spray-drying showed the best characteristics to obtain a natural antimicrobial additive.

中文翻译：

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用于抗菌天然粉末添加剂的柠檬醛封装：壁材料的性能和干燥过程

通过喷雾和冷冻干燥对柠檬醛封装进行分析，以获得粉末状抗菌添加剂。含有藻酸盐和改性淀粉 (Capsul®) 作为包封剂（分别为 1% 和 3% w/w）以及不同浓度（范围为 1:1–1:4 柠檬醛：麦芽糖糊精）的麦芽糖糊精作为壁材料的不同配方准备好了。评估粉末的物理特性和抗大肠杆菌的抗菌特性，以获得天然抗菌食品添加剂。考虑到包封率 (EY) (75%–80%)、包封率 (EE) (~78%) 和粒径 (5–10 μm)，通过喷雾干燥获得的柠檬醛：胶囊：麦芽糖糊精粉末显示出最佳的物理性质。 ），并且在较低的添加浓度（1.5%–2% w/w）下具有较高的微生物抑制作用，与​​使用的麦芽糖糊精浓度无关。通过冷冻干燥乳液获得的粉末显示 EY ~70%，EE ~70%，粒径在 80 至 1250 μm 之间，并且抗菌活性的再水化百分比较高（2.5%–4% w/w）。麦芽糖糊精浓度的增加导致 %EE 的降低、颗粒尺寸的增加以及抑制微生物生长所需的粉末浓度的增加。因此，通过喷雾干燥显示的1:1:1柠檬醛：胶囊：麦芽糖糊精的配方显示出获得天然抗菌添加剂的最佳特性。