Quality evaluation of raw and processed Corni Fructus by UHPLC-QTOF-MS and HPLC coupled with color determination

Corni Fructus (CF), used for thousands of years in Asia as food and medicine, has different therapeutic effects before and after processing. In the past work, the quality assessment of Corni Fructus focused on the limited chemical compounds and rarely correlated external properties, such as color. The traditional sensory assessment relies partly on human eyes, which is quick but lacks objectivity. On a Shimadzu LC-20AD liquid chromatograph system equipped with a diode-array detector (DAD), we determined six major compounds (gallic acid, 5-hydroxymethyl-2-furaldehyde, morroniside, loganin, sweroside, and cornuside I). The extract was analyzed using ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS) after the solid-phase extraction (SPE) step. Totally 58 compounds in raw and processed Corni Fructus were identified in negative and positive ion modes according to tandem mass spectrometry (MS/MS) fragments. Iridoids, carboxylic acids, tannins, flavonoids, triterpenes, fatty acids, saccharides, phospholipids, polysaccharide, amino acid, amide, furan, catechol, aldehyde, fatty alcohol and vitamin were included. A multivariate statistical analysis based on UHPLC-QTOF-MS filtered 17 differential compounds between raw and processed products. The CM-5 colorimeter was applied for digitizing surface and powder color. The contents of gallic acid, morroniside, loganin, cornuside I, and sweroside significantly correlated with color parameters in raw Corni Fructus, particularly a_dp* and b_dp* , but not in processed products, according to Spearman correlation analysis. MS peak area of four compounds in raw products correlated significantly with color parameters L_dp* , a_dp* , b_dp* , L_pd* , a_pd* , b_pd* , respectively, while three compounds in processed products with L_pd* , a_pd* , b_pd* . It revealed the relationship between compounds and color of Corni Fructus and the crucial compounds to color. In this study, we successfully developed a method for comprehensive quality evaluation of Corni Fructus that combines HPLC, UHPLC-QTOF-MS, and color determination.