Effect of postharvest processing on quality traits of Radix Gentianae Macrophyllae: A integrative analysis of metabolomics and proteomics

The dried roots and rhizomes of Radix Gentianae Macrophyllae are widely used as food material or medicinal crops. "Sweating" is a traditional postharvest processing method, the basic processing procedure consists of softening, stacking and drying. The aim of this paper is to unveil the scientific connotation responsible for the "Sweating" processing in Radix Gentianae Macrophyllae during postharvest. Thus, the effect of different postharvest processing methods on the metabolic pathways of Radix Gentiasnae Macrophyllae was studied by the non-targeted metabolomic technique in combination with the label-free proteomics approach. The results showed that the differentially accumulated metabolites and abundant proteins were mainly enriched in the pathways of phenylalanine, tyrosine and tryptophan biosynthesis, polyphenols and terpenoids biosynthesis. "Sweating" has a greater up-regulation effect on these pathways than "Non-sweating", and can induce protein expression and metabolite accumulation associated with the quality traits of Radix Gentianae Macrophyllae. The results provide a detailed explanation of the scientific connotation of crucial steps of "Sweating" processing wherein opportunities existed for taking appropriate measures to enhance the accumulation of bioactive ingredients. These findings will serve as significant references for enhancing the postharvest processing technology of Radix Gentianae Macrophyllae and similar plants, resulting in higher product quality for food or plant materials production.