Xin Li,Guangyan Yao,Xiaopeng Chen,Jie Huang,Jiezhen Liang,Xiaojie Wei,Biao Huang,Linlin Wang
Quality deterioration due to undesirable discolorations in crude pine oleoresin during storage is a major problem limiting its subsequent processing applications. To reveal the essence of color changes, the browning phenomenon and comprehensive mechanism of crude pine oleoresin during storage were investigated in depth using an approach based on high-resolution mass spectrometry metabolomics . Crude pine oleoresin was stored with sterile, deionized, tap, and pond water for 30, 60, 90, 120, 150, and 180 days, respectively. The changes in browning substrate were detected by tracking analysis protein, reducing sugar, ascorbic acid , and total phenol content, browning was evaluated through colorimeter measurement. The metabolism of crude pine oleoresin in different storage times was uncovered that total color difference (Δ E ) increased with storage time, and the browning of crude pine oleoresin soaked in tap water was greatest while soaked in deionized water exhibited the mildest. The content of reducing sugars, proteins, and total phenols increased with storage time, whereas the ascorbic acid content tended to increase and then decrease. Furthermore, the metabolomics analyses showed that 1,194 and 979 differentially metabolized compounds were found between days 120 and days 150, and days 120 and days 180. The metabolite profiles in the water samples changed as crude pine oleoresin storage time increased. Most carbohydrate content decreased, and the phenols and organic acids content increased. Metabolic network mapping linking differentially metabolized compounds by mapping different biosynthetic pathways proved that caffeoylquinic acid and catechin play a key role in the browning of crude pine oleoresin during storage: caffeoylquinic acid forms black iron complexes with iron, and catechin is oxidized to catechol quinone, which eventually produces a yellow dimer. This study will provide a scientific basis for developing or choosing more effective methods for controlling the discoloration of crude pine oleoresin and other similar products during storage.
Mei Yang,Minzhen Yin,Shanshan Chu,Yujiao Zhao,Qingying Fang,Ming'en Cheng,Huasheng Peng,Luqi Huang
Introduction Astragali Radix has been used for over 2000 years in traditional Chinese medicine. Its secondary xylem “Jinjing” and secondary phloem “Yulan” are important for evaluating the quality of the Daodi medicinal material in China. However, its systematic characterisation has not been conducted. Objective This study aims to investigate the colour, chemical compounds, and antioxidant capacity of the secondary xylem and phloem of Astragali Radix on the basis of untargeted metabolomics, broadening the application scope of Astragali Radix in food and pharmaceutical industries. Methods The L* , a* , and b* of the secondary xylem and phloem were measured by colorimetry, and the chemical compounds were identified and quantified by ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and high-performance liquid chromatography-diode array detector-evaporative light scattering detection. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays were conducted to evaluate their antioxidant capacity. Results Thirty-one compounds were identified by UPLC-Q-TOF-MS. The secondary xylem exhibited high parameter b* , flavonoid content, and antioxidant capacity, while the secondary phloem was rich in astragalosides. The colour parameters of well-defined type A significantly varied from those of the other types. Well-defined type A also exhibited the highest antioxidant activity and flavonoid content, followed by middle type A-like, middle type B-like, and yellow shading type B. Conclusion The colour parameters, chemical compounds, and antioxidant capacity among the different transverse sections of secondary xylem and phloem varied. The yellow colour of secondary xylem was correlated to high flavonoid content and antioxidant activity, and well-defined type A of Astragali Radix had better quality than other types.
危险品化学品经营许可证（带存储）