选择合适的益生菌菌株对于将其成功包含在食品中至关重要。这些菌株必须经得起加工才能达到≥106CFU/g的消费者,确保有效的益生菌功能。由于在加工过程中对温度的敏感性,在商业产品中实现这一点是具有挑战性的。在这项工作中,罗伊氏乳杆菌DSM17938通过离子凝胶化(用藻酸盐或果胶)然后通过聚合物涂层(用乳清蛋白浓缩物或壳聚糖)进行微囊化。然后,这种微胶囊被掺入草莓泥,随后在三个温度(40°C,45°C,和50°C)通过折光窗口®。最终目的是从技术角度证明所提出方法的有效性。益生菌活力的动力学曲线显示高细胞负载(>109CFU/g)。此外,平均封装效率为91%,粒径约为200μm。随着干燥温度和时间的增加,观察到微生物的生存力降低。作为上述的证明,在特定情况下,在45°C和50°C下干燥,活细胞被发现长达165分钟和90分钟,分别;同时,在40°C下干燥,即使在240分钟后仍报告活细胞。当将涂有乳清蛋白浓缩物的微胶囊掺入果泥中时,在40°C下干燥240分钟可实现最大的生存力保存;该程序显示出生产水分脱水草莓小吃的巨大潜力(15%),水活度(aw<0.6),和适用于功能性食品的生存力(≥106CFU/g)。乳清蛋白浓缩物的膜稳定特性可以防止细胞损伤。相比之下,壳聚糖包衣胶囊中的益生菌显示出降低的活力,可能是由于抗菌性能和裂缝的形成。这些发现标志着添加益生菌后脱水零食生产的突破,解决在加工过程中保持这些益生菌活力的挑战;因此,开启了开发益生菌草莓零食的可能性。
The selection of appropriate probiotic strains is vital for their successful inclusion in foods. These strains must withstand processing to reach consumers with ≥106 CFU/g, ensuring effective probiotic function. Achieving this in commercial products is challenging due to sensitivity to temperature during processing. In this work, Lactobacillus reuteri DSM 17938 was microencapsulated by ionic gelation (with alginate or pectin) followed by polymeric coating (with whey protein concentrate or chitosan). Then, such microcapsules were incorporated into a strawberry puree, which was subsequently dehydrated at three temperatures (40 °C, 45 °C, and 50 °C) by Refractance Window®. The ultimate aim was to demonstrate the efficacy of the proposed methods from a technological point of view. Kinetic curves of the probiotic\'s viability showed a high cell loading (>109 CFU/g). Additionally, an average encapsulation efficiency of 91% and a particle size of roughly 200 µm were found. A decrease in the viability of the microorganism was observed as drying temperature and time increased. As a demonstration of the above, in a particular case, drying at 45 °C and 50 °C, viable cells were found up to 165 min and 90 min, respectively; meanwhile, drying at 40 °C, viable cells were reported even after 240 min. The greatest viability preservation was achieved with Refractance Window® drying at 40 °C for 240 min when microcapsules coated with whey protein concentrate were incorporated into puree; this procedure showed great potential to produce dehydrated strawberry snacks with moisture (15%), water activity (aw < 0.6), and viability (≥106 CFU/g) suitable for functional foods. The membrane-stabilizing properties of whey protein concentrate could prevent cell damage. In contrast, probiotics in chitosan-coated capsules showed reduced viability, potentially due to antimicrobial properties and the formation of cracks. These findings signify a breakthrough in the production of dehydrated snacks with the addition of probiotics, addressing challenges in preserving the viability of these probiotics during processing; thus, opening the possibility for the development of a probiotic strawberry snack.