The objective of this work was to evaluate the potential of whey protein concentrate (WPC), native agave fructans (NAF), and their mixture (WPC-NAF, 1:1 w/w) as wall materials and evaluate the physicochemical properties and stability of encapsulated Enterococcus faecium during the spray drying, storage, and passage through the simulated gastrointestinal tests. The encapsulated microorganisms with WPC-NAF by spray drying showed greater viability (9.26 log CFU/g) and a higher microencapsulation yield (88.43%). They also had a smaller reduction in the cell count (0.61 log cycles), while the microcapsules produced with NAF had the greatest reduction in viability during the simulated gastrointestinal tests. Similarly, probiotics encapsulated with WPC-NAF revealed a higher survival rate (> 8 log CFU/g) when stored at a water activity of 0.328. The thermal analysis showed that the addition of NAF to the WPC produced a slight shift in the Tg towards temperatures higher than that shown by NAF. Therefore, this study provides evidence that the spray drying process was appropriate to encapsulate the probiotic strain Enterococcus faecium and that the mixture WPC-NAF protected it from adverse drying conditions and improved the viability of Enterococcus faecium during storage and simulated gastrointestinal tests, demonstrating that the combination of NAF and WPC as encapsulating material is adequate in the production of more stable microcapsules with potential application in various foods.

Key Points

• E. faecium was successfully encapsulated in WPC and NAF.

• WPC-NAF offered protection to E. faecium in the gastrointestinal tests and during storage.

• Aw around 0.328 positively influenced the viability of the microorganism during storage.

这项工作的目的是评估乳清蛋白浓缩物（WPC），天然龙舌兰果聚糖（NAF）及其混合物（WPC-NAF，1：1 w / w）作为墙体材料的潜力，并评估其理化性质和稳定性。粪肠球菌的制备在喷雾干燥，储存和通过模拟胃肠道测试的过程中。通过喷雾干燥用WPC-NAF包裹的微生物表现出更高的生存力（9.26 log CFU / g）和更高的微囊化产率（88.43％）。它们的细胞数减少幅度也较小（0.61 log周期），而用NAF生产的微胶囊在模拟胃肠道测试中的生存力降低幅度最大。同样，用WPC-NAF封装的益生菌在水分活度为0.328时显示出更高的存活率（> 8 log CFU / g）。热分析表明，向WPC中添加NAF会使Tg向温度稍高于NAF所示温度的方向发生转变。因此，这项研究提供了证据证明喷雾干燥过程适合封装益生菌菌株粪肠球菌以及WPC-NAF混合物可保护其免受不利的干燥条件的影响，并改善了粪肠球菌在储存和胃肠道模拟试验过程中的生存能力，证明NAF和WPC的组合作为包封材料足以生产更稳定的微囊，在各种食品中的潜在应用。

关键点

•屎肠球菌已成功封装在WPC和NAF中。

•WPC-NAF在胃肠道测试和储存过程中为屎肠球菌提供了保护。

•约0.328的Aw积极影响微生物在储存过程中的生存能力。