Nuñez Helena, Jaques Aldonza, Belmonte Karyn, Elitin Jamil, Valdenegro Mónika, Ramírez Cristian, Córdova Andrés
Departamento de Ingeniería Química y Ambiental, Universidad Técnica Federico Santa María, P.O. Box 110-V, Valparaíso 2390123, Chile.
Programa de Doctorado de Ciencias Agroalimentarias, Facultad de Ciencias Agronómicas y de los Alimentos, Pontifica Universidad Católica de Valparaíso, Valparaíso 2340025, Chile.
Foods. 2024 Jun 3;13(11):1756. doi: 10.3390/foods13111756.
The objective of this study was to develop a dried apple snack enriched with probiotics, evaluate its viability using Refractance Window (RW) drying, and compare it with conventional hot air drying (CD) and freeze-drying (FD). Apple slices were impregnated with and dried at 45 °C using RW and CD and FD. Total polyphenol content (TPC), color (∆E*), texture, and viable cell count were measured, and samples were stored for 28 days at 4 °C. Vacuum impregnation allowed for a probiotic inoculation of 8.53 log CFU/gdb. Retention values of 6.30, 6.67, and 7.20 log CFU/gdb were observed for CD, RW, and FD, respectively; the population in CD, RW remained while FD showed a decrease of one order of magnitude during storage. Comparing RW with FD, ∆E* was not significantly different ( < 0.05) and RWTM presented lower hardness values and higher crispness than FD, but the RW-dried apple slices had the highest TPC retention (41.3%). Microstructural analysis showed that RW produced a smoother surface, facilitating uniform moisture diffusion and lower mass transfer resistance. The effective moisture diffusion coefficient was higher in RW than in CD, resulting in shorter drying times. As a consequence, RW produced dried apple snacks enriched with probiotics, with color and TPC retention comparable to FD.
本研究的目的是开发一种富含益生菌的苹果干零食，使用折射窗（RW）干燥法评估其存活率，并将其与传统热风干燥（CD）和冷冻干燥（FD）进行比较。将苹果片用[具体物质]浸渍，然后分别使用RW、CD和FD在45°C下干燥。测量了总多酚含量（TPC）、颜色（∆E*）、质地和活菌数，并将样品在4°C下储存28天。真空浸渍使益生菌接种量达到8.53 log CFU/gdb。CD、RW和FD的保留值分别为6.30、6.67和7.20 log CFU/gdb；在储存期间，CD和RW中的菌数保持不变，而FD中的菌数下降了一个数量级。与FD相比，RW的∆E*无显著差异（<0.05），且RW处理的苹果干硬度值更低、脆度更高，但RW干燥的苹果片TPC保留率最高（41.3%）。微观结构分析表明，RW产生的表面更光滑，有利于水分均匀扩散且传质阻力更低。RW中的有效水分扩散系数高于CD，导致干燥时间更短。因此，RW生产出了富含益生菌的苹果干零食，其颜色和TPC保留率与FD相当。
