A rapid chemometrics model for antioxidant substance mining of Chinese dwarf cherry [Cerasus humilis(Bge.) Sok.] based on polyphenol profile and antioxidant capacity of 30 germplasms

Chinese dwarf cherry (Ouli) is a native shrub in northwest China with high ecological value, but the nutritive potential remains to be explored. In this study, the total content of polyphenols, flavonoids, proanthocyanidins, and anthocyanins of Ouli from 30 germplasms were measured, and the antioxidant activities were evaluated by FRAP and ABTS assays. The polyphenol profile was determined by ultra-high-performance liquid chromatography-high resolution mass spectrometry. Grey relational analysis and partial least squares were utilized to build chemometrics models for selecting antioxidant compounds. The contents of total flavonoids, proanthocyanidins, phenols and total anthocyanidins of 30 germplasms of Ouli were 119.92–668.76 mg/100 g fresh weight (FW), 90.81–555.44 mg/100 g FW, 148.42–390.43 mg/100 g FW, 0.02–17.26 mg/100 g FW, respectively. A total of 61 compounds were identified, including 40 flavonoids (26 flavonols, 4 anthocyanins, 6 dihydroflavonols, 2 dihydrochalcones, and 2 flavones), 12 proanthocyanidins, 6 phenolic acids, and 3 types of other class compounds (one stilbene and two phenols). The proanthocyanidin compounds in Ouli contributes most to the total antioxidant capacity with the antioxidant rank that procyanidin trimer > tetramer > dimer ≈ monomer. Catechin and procyanidin B1 were the most abundant compounds and were 18.45–162.50 μg/g FW and 30.52–149.42 μg/g FW, respectively. Shanxi (SX) 2 and SX10 could be considered as potential germplasms, and proanthocyanidins could be chosen as a characteristic nutrient evaluation index of Ouli. This study not only takes a key step to lay the groundwork for further research of Ouli but also provides a reference for the discovery of the functional ingredients of other foods.