Abstract

This study was aimed to optimize spray drying conditions (inlet air temperature: 120–180 °C) and wall material composition (maltodextrin (MD), gum Arabic (AG)) to obtain the powder of myrtle berry (Myrtus communis L.) extract having higher biological activities. Response surface methodology was used where maximum drying yield and minimum loss of total phenolics were dependent variables. Two optimum conditions were obtained: (1) a composition of 5.75 g maltodextrin/100 mL extract and 9.25 g gum Arabic/100 mL extract as wall materials at 180 °C inlet air temperature; (2) a composition of 3.75 g maltodextrin/100 mL extract and 11.25 g gum Arabic/100 mL extract as wall materials at 120 °C inlet air temperature. The second one was preferred due to lower phenolic losses. Optimum drying conditions provided the highest powder yield (39.89%) and least phenolic loss (16.95%). The bulk and tapped densities of the obtained powders were determined as 375.6 ± 9.7 and 609.6 ± 22.5 kg/m³, respectively. Total phenolics content and antioxidant activity of the obtained powder were found as 0.78 ± 0.01 g gallic acid equivalent (GAE)/100 g dry basic (db) and 1.69 ± 0.07 g trolox equivalent antioxidant activity (TEAC)/100g db, respectively. Particle size distribution was found between 0.69 and 16.175 µm. Epicatechin-3-0-gallate (EGC) and myricetin were main phenolics while D-limonene and α-pinene were main volatile components in the crude extract as well as in final powder product.

摘要

本研究旨在优化喷雾干燥条件（进气温度：120–180 °C）和壁材成分（麦芽糊精（MD）、阿拉伯树胶（AG））以获得桃金娘（Myrtus community）粉末。L.) 具有更高生物活性的提取物。使用响应面方法，其中最大干燥产量和总酚类物质的最小损失是因变量。获得了两个最佳条件：(1) 5.75 g 麦芽糊精/100 mL 提取物和 9.25 g 阿拉伯树胶/100 mL 提取物作为壁材，入口空气温度为 180 °C；(2) 由 3.75 g 麦芽糊精/100 mL 提取物和 11.25 g 阿拉伯树胶/100 mL 提取物组成的组合物作为壁材，进气温度为 120 °C。由于较低的酚类损失，第二个是优选的。最佳干燥条件提供了最高的粉末收率 (39.89%) 和最少的酚类损失 (16.95%)。所得粉末的堆积密度和振实密度分别为 375.6 ± 9.7 和 609.6 ± 22.5 kg/m ³， 分别。所得粉末的总酚含量和抗氧化活性分别为 0.78 ± 0.01 g 没食子酸当量 (GAE)/100 g 干碱 (db) 和 1.69 ± 0.07 g trolox 当量抗氧化活性 (TEAC)/100g db。发现粒径分布在 0.69 和 16.175 µm 之间。表儿茶素-3-0-没食子酸酯 (EGC) 和杨梅素是主要的酚类物质，而 D-柠檬烯和 α-蒎烯是粗提取物和最终粉末产品中的主要挥发性成分。