Potential application of domestic solar dryers for coriander leaves: Drying kinetics, thermal efficiency, and quality assessment

Abstract

AbstractCoriander (Coriandrum sativum L.) is a highly perishable crop with a shelf‐life of a few days under refrigerated conditions. Solar drying is one of the economical, hygienic and eco‐friendly methods of food preservation. During this study, fresh coriander was pre‐treated in a solution of 0.1% magnesium chloride, 0.1% sodium bicarbonate and 2.0% KMS for 15 min before solar or open sun drying. There were two types of solar dryers used, namely: PAU advanced domestic solar dryer and PAU domestic solar dryer. Solar dryers were evaluated and compared with open sun drying for drying kinetics, thermal efficiency, and product quality. The quality parameters determined were total color difference, total flavonoid content, total chlorophyll content, and ascorbic acid content. For drying of coriander, ADSD achieved the maximum thermal efficiency (18.56%) and minimum solar energy input (12.56 MJ/kg) out of the various drying systems under consideration. Additionally, ADSD samples had the highest quality retention in terms of the highest total flavonoid content (1.23 mg/100 g), total chlorophyll content (24.14 mg/100 g) and ascorbic acid content (24.29 mg/100 g).