Departamento de Bioingenierias, Tecnologico de Monterrey, Monterrey 76158, Mexico.
Molecules. 2020 Mar 6;25(5):1190. doi: 10.3390/molecules25051190.
Chokecherry ( L.) is rich in bioactive molecules as phenolics, which can act as antioxidants, anti-inflammatory, anticancer, among others; however, due to its high perishability, most of this fruit is wasted. Freezing and sun drying have been the most adopted techniques to avoid its postharvest deterioration. Nevertheless, both processes have presented some drawbacks as high storage costs and losses of bioactive molecules. Therefore, to preserve these molecules, this study compared the impact of convective airflow drying (CAD), freezing (FR), freeze drying (FD), and swell drying (SD). Total phenolics content (TPC), total flavonoids content (TFC), kuromanin concentration (KC), and antioxidant activity (antiradical activity (ARA) and Trolox equivalent antioxidant capacity assay (TEAC)) of chokecherries were measured. "Swell drying" is a drying process coupling convective airflow drying to the Instant Controlled Pressure Drop (DIC) expansion. A central composite rotatable design was applied to optimize the DIC variables and responses. Results showed that both freezing and swell drying effectively preserve the TPC, TFC, KC, and ARA. Moreover, SD samples also presented the highest TEAC. Contrary, in the case of CAD, it caused the highest losses of both antioxidant content and activity. Swell drying remedies the shrinkage and collapsing of dried food structure, which results in a better antioxidants extraction.
稠李（L.）富含生物活性分子，如酚类物质，具有抗氧化、抗炎、抗癌等作用；然而，由于其高度易腐性，大部分果实都被浪费了。冷冻和晒干是避免其采后变质的最常用技术。然而，这两种方法都存在一些缺点，如高储存成本和生物活性分子的损失。因此，为了保存这些分子，本研究比较了对流空气干燥（CAD）、冷冻（FR）、冷冻干燥（FD）和膨化干燥（SD）的影响。测定了稠李的总酚含量（TPC）、总黄酮含量（TFC）、苦龙素浓度（KC）和抗氧化活性（抗自由基活性（ARA）和 Trolox 当量抗氧化能力测定（TEAC））。“膨化干燥”是一种将对流空气干燥与瞬时控制压力下降（DIC）膨胀相结合的干燥工艺。采用中心组合旋转设计优化 DIC 变量和响应。结果表明，冷冻和膨化干燥都能有效地保持 TPC、TFC、KC 和 ARA。此外，SD 样品的 TEAC 也最高。相比之下，在 CAD 的情况下，它导致了抗氧化剂含量和活性的最高损失。膨化干燥可修复干燥食品结构的收缩和坍塌，从而提高抗氧化剂的提取效果。
