ObjectiveTo investigate differential metabolites associated with browning in the post-harvest processing of Pinelliae Rhizoma， providing data support for elucidating the key metabolites and metabolic pathways involved in browning， and developing safe and efficient sulfur-free processing techniques. MethodsUltra-performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometry（UPLC-QTRAP-MS/MS） was used to detect the metabolites of Pinelliae Rhizoma at different browning stages（0， 8， 16 h） for widely targeted metabolomics. Subsequently， Multivariate statistical analysis of metabolites was conducted using principal component analysis（PCA）， hierarchical cluster analysis（HCA）， orthogonal partial least squares-discriminant analysis（OPLS-DA）， and K-means cluster analysis. Differential metabolites at different browning stages were screened based on variable importance in the projection（VIP） value>1 and |log₂fold change（FC）|≥1， and metabolic pathway enrichment analysis was performed using Kyoto Encyclopedia of Genes and Genomes（KEGG）. ResultsA total of 1 416 metabolites were identified across the three browning stages of Pinelliae Rhizoma， predominantly comprising amino acids and their derivatives（239）， lipids（219）， alkaloids（156）， phenolic acids（121）， terpenoids（113）， and flavonoids（111）. A two-by-two comparison of the three browning phases， yielded 622 differential metabolites that were significantly enriched in the phenylpropanoid biosynthesis， flavone and flavonol biosynthesis， and purine metabolic pathway. Further analysis revealed that carbohydrates such as D-mannose and turanose， phenolic acids such as 1-O-caffeoyl-6-O-glucosyl-β-D-glucose， dicaffeoylshikimic acid， and flavonoids such as epigallocatechin gallate， vitexin-7-O-rutinoside， luteolin-7-O-（6″-malonyl）glucoside-5-O-arabinoside， catechin gallate， epicatechin gallate， isovitexin-7-O-glucoside-2″-O-rhamnoside， apigenin-7-O-rutinoside-4ʹ-O-sophoroside， 3，5，3ʹ，4ʹ，5ʹ-penta-hydroxyflavan-7-gallate may act as browning substrates and play important roles in the browning process. ConclusionCarbohydrates， phenolic acids， and flavonoids may serve as key substrates in the browning process of Pinelliae Rhizoma， involving pathways such as phenylpropanoid biosynthesis， flavone and flavonol biosynthesis， and purine metabolism， which can provide a theoretical basis for further exploration of the browning mechanism.

Hippophae rhamnoides is a traditional Chinese medicine with homology of medicine and food， which has the effects of relieving cough and resolving phlegm， strengthening the stomach and digestion， and promoting blood circulation and resolving blood stasis. H. rhamnoides contains not only flavonoids， phenols， proteins， vitamins， and amino acids but also abundant polysaccharides. In order to explore the functional value and current research status of H. rhamnoides polysaccharides， this study systematically summarized the extraction process， structural characteristics， pharmacological effects， and mechanism of action of H. rhamnoides polysaccharides by reviewing Chinese and foreign literature. The results showed that H. rhamnoides polysaccharides have anti-tumor， hypoglycemic， antioxidant， immune regulation， anti-inflammatory， and anti-hyperlipidemia functions and could improve intestinal microbiota. There were various extraction processes for polysaccharides， including hot water extraction， microwave extraction， ultrasonic extraction， enzymatic extraction， flash extraction， ultrasonic-microwave synergistic extraction， emerald hot water extraction， enzymatic-ultrasonic synergistic extraction， etc. Based on comprehensive analysis， hot water extraction is suitable for industrial development and application. However， multiple homogeneous polysaccharides have been isolated and purified from H. rhamnoides polysaccharides， but their efficacy， structure， and structure-activity relationship still need to be further explored and studied. This study can provide a reference for the research and development of H. rhamnoides polysaccharides.