LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
Department of Mechanical Engineering, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
Bioresour Technol. 2021 Aug;333:125207. doi: 10.1016/j.biortech.2021.125207. Epub 2021 Apr 22.
Apple pomace valuation has been impaired by its high perishability and absence of fast drying approaches demanded by industry. This work aimed to assess the feasibility of Microwave Hydrodiffusion and Gravity (MHG) process applied for apple pomace drying using discrete delivery powers (300-900 W) and comparison with hot-air drying (40-100 °C). To dry 0.4 kg of apple pomace (81% moisture), hot-air drying required 3.6-9.9 h with estimated water evaporation flux of 1.0-3.5 mL/min. For MHG, which processed 1.2 kg, these corresponded to 1.0-2.6 h and 5.1-13.9 mL/min. Furthermore, MHG allowed water recovery containing part of apple pomace phenolic compounds and carbohydrates. The dried pomace was stable for 2 years, after which phenolic compounds and polysaccharides were still recoverable by hot water extractions. These results pave the way for MHG to be used for apple pomace and other by-products preservation, boosting their conversion into valuable co-product for valuation of its components.
苹果渣的价值因高易腐性和缺乏工业所需的快速干燥方法而受到影响。本研究旨在评估微波水扩散和重力（MHG）工艺应用于苹果渣干燥的可行性，采用离散输送功率（300-900 W），并与热风干燥（40-100°C）进行比较。为了干燥 0.4 公斤的苹果渣（81%水分），热风干燥需要 3.6-9.9 小时，估计水蒸发通量为 1.0-3.5 毫升/分钟。对于处理 1.2 公斤的 MHG，相应的时间为 1.0-2.6 小时和 5.1-13.9 毫升/分钟。此外，MHG 允许回收含有部分苹果渣酚类化合物和碳水化合物的水。干燥的苹果渣在 2 年内保持稳定，之后仍可通过热水提取回收酚类化合物和多糖。这些结果为 MHG 用于苹果渣和其他副产品的保存铺平了道路，促进了它们转化为有价值的副产物，以评估其成分的价值。
