Evaluation of antioxidant capacity and bioactive compounds in Capsicum annum L. red peppers following drying in a polycarbonate greenhouse

The current study aims to provide insights into the drying of agro products, with a specific focus on Capsicum annum L. (red pepper). Among open sun drying (OSD), polyethylene bag drying (PBD), and polycarbonate sheet drying (PCSD), PCSD was efficient requiring around 24 hours with a maximum yield of 350 g of dried product per 1000 g of supplied fresh peppers. The PCSD dried chili also showed greater retention of antioxidant markers (capsaicin and dihydrocapsaicin) than OSD and PBD as evidenced by UV-VIS spectroscopy. Additionally, the PCSD dried chili demonstrated highest antioxidant potential via ABTS (2, 2'-Azinobis-3-Ethylbenzothiazoline-6-Sulfonic Acid). Interestingly, the presence of various aromatic compounds and other chemical groups, indicated the occurrence of capsaicin and dihydrocapsaicin in each drying method used. The study suggests that PCSD sheet drying is an efficient and cost-effective approach that can conserve the antioxidant potential of agro products such as red pepper.