Cardamom, known by the botanical name Elettaria cardamomum, is a well-known spice which is increasingly used in the field of cosmetics and industrial applications in the form of dried powders and oil. However, usage of cardamom is limited by its moisture content (around 80% in wet basis) and for effective oil extraction and usage, cardamom needs to be dried to a moisture content of less than 10% (in wet basis) prior to usage. Solar driers are traditionally used for cardamom drying and fluidized bed driers and tray driers are also used for industrial-level large-scale drying. During drying, loss of bioactive like phenolics, flavonoids and antioxidants become inevitable. Under such a scenario, this study explores the performance of low-temperature, low-humidity dryers namely refrigeration adsorption dehumidified dryers (RADD), designed and developed by CSIR-NIIST, for retention of bioactives during drying. To assess and compare the RADD with traditional dryers, experiments were performed in a tray dryer, solar dryer and fluidized bed dryer and the results are compared with RADD. It was found that cardamom dried in RADD retained around 70–75% of total phenolic, flavonoid and anti-oxidant compounds, whereas retention in other conventional drying methods was in the range 35–60% only. Advanced analysis such as SEM, FTIR and GC-MS was also done to evaluate the morphological changes, functional group changes and difference in essential oil composition due to different drying methods. Considering the overall result it has been proved that RADD has several advantages over the conventional dryers (due to low temperature and low humidity inside RADD) and thus can be used for drying cardamom which will promise good quality cardamom with maximum retention or preservation of all the bioactives. Thus, RADD is found to be a promising alternative for fluidized bed dryers and also it performs better than other conventional drying methods.

小豆蔻，以植物学名称Elettaria cardamomum闻名，是一种众所周知的香料，越来越多地以干粉和油的形式用于化妆品和工业应用领域。然而，豆蔻的使用受到其水分含量（湿基约 80%）的限制，并且为了有效地提取和使用豆蔻，豆蔻在使用前需要干燥至水分含量低于 10%（湿基）。太阳能干燥机传统上用于豆蔻干燥，流化床干燥机和盘式干燥机也用于工业级的大规模干燥。在干燥过程中，酚类、类黄酮和抗氧化剂等生物活性物质的损失变得不可避免。在这种情况下，本研究探讨了由 CSIR-NIST 设计和开发的低温低湿干燥机（即冷冻吸附除湿干燥机 (RADD)）在干燥过程中保留生物活性物质的性能。为了评估和比较 RADD 与传统干燥机，在盘式干燥机、太阳能干燥机和流化床干燥机中进行了实验，并将结果与​​ RADD 进行了比较。结果发现，在 RADD 中干燥的小豆蔻保留了大约 70-75% 的总酚类、类黄酮和抗氧化化合物，而在其他传统干燥方法中保留仅在 35-60% 的范围内。还进行了 SEM、FTIR 和 GC-MS 等高级分析，以评估由于不同干燥方法导致的形态变化、官能团变化和精油成分的差异。考虑到整体结果，已经证明 RADD 与传统干燥机相比有几个优势（由于 RADD 内部温度低和湿度低），因此可用于干燥豆蔻，这将保证豆蔻的所有豆蔻最大限度地保留或保存。生物活性物质。因此，RADD 被发现是流化床干燥机的一种有前途的替代品，而且它的性能优于其他传统干燥方法。