The comprehensive assessment of moxa wool and by-products after postharvest technology in a novel original herb: Artemisia stolonifera (Maxim.) Kom.

Artemisia stolonifera (Maxim.) Kom. Has been identified as a novel source plant for moxa wool production in China. The manufacturing process of moxa wool generated various by-products from harvested aerial parts (leaves and stems). However, the chemical components and tissue formation mechanisms of these by-products remain poorly characterized. We collected five by-products (three ash types: CH, XH, CCH; two leaf residues: CZ and XZ) during the production of four main moxa wool grades (91 R, 31 R, KLR, HR). These moxa wool and by-products were systematically investigated via microscopic scanning, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry, and ultra-performance liquid chromatography, as well as conducted analysis of antioxidant activity combined with chemometrics and correlation analysis. The results indicated that moxa wool predominantly contained nonglandular trichomes and glandular trichomes. Total of 32, 34, 39, 20, 26, 25, 40, 33, 41 volatile components were authenticated from 91 R, 31 R, CCH, CZ, XZ, CH, XH, KLR, and HR, respectively. CCH and CH had high contents of phenolic acid and significantly high antioxidant activity compared with other 5 by-products, while high-grade moxa wool had lowest contents of phenolic acid. The comprehensive analysis covered the whole products of processing of moxa wool, which would provide vital references for rational utilization of by-products and standardized quality assessment protocols of high-grade moxa wool.