Quantification of cranberry proanthocyanidins by normal‐phase high‐performance liquid chromatography using relative response factors

• Published in: Phytochemical analysis Vol. 31; no. 6; pp. 874 - 883
• Main Authors: Sintara, Marsha, Wang, Yifei, Li, Lin, Liu, Haiyan, Cunningham, David G., Prior, Ronald R., Chen, Pei, Chang, Tony, Wu, Xianli
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.11.2020
• Subjects: Berries; Chromatography; Chromatography, High Pressure Liquid; Cranberries; cranberry; Degree of polymerization; Epicatechin; Family; Food production; Fruit - chemistry; High performance liquid chromatography; Linearity; Liquid chromatography; Mass spectrometry; Mass spectroscopy; NP‐HPLC; Oligomers; PAC; Plant Extracts; Polymers; Proanthocyanidins; Proanthocyanidins - analysis; relative response factor; Urinary tract; Vaccinium macrocarpon; relative response factor; cranberry; PAC; proanthocyanidins; NP-HPLC
• ISSN: 0958-0344; 1099-1565
• DOI: 10.1002/pca.2952

Introduction American cranberries (Vaccinium macrocarpon) contain primarily A‐type proanthocyanidins (PACs), which have been shown to prevent urinary tract infection. Currently, the accurate quantification of cranberry PACs is still lacking. Objective A normal‐phase high‐performance liquid chromatography (NP‐HPLC) method using relative response factors was developed and validated to quantify cranberry PAC oligomers and polymers. Materials and Methods PAC oligomers with degree of polymerisation (DP) 3–9 and total polymers were isolated from the cranberry juice concentrate. Characterisation of the isolated PAC oligomers was performed by ultra‐performance liquid chromatography‐high resolution mass spectrometry. The relative response factors of oligomers from DP 2–9 and total polymers were determined against procyanidin A2. Method validation was conducted to assess limit of detection, limit of quantification, the linearity and working range, precision and accuracy. In addition, quantifications of PACs by NP‐HPLC using relative response factors and two other commonly used methods were conducted in three cranberry food products. Results Cranberries PACs oligomers contained both A‐type and B‐type linkage, with epicatechin and epigallocatechin as basic units. Method validation results suggested this method is reliable and reproducible. Quantifications of PACs by NP‐HPLC using relative response factors yielded higher values than that by the other two methods. Conclusion A NP‐HPLC method using the relative response factors was developed and validated. This method provides a more accurate approach in determining cranberry PACs. It can be used to quantify individual oligomers from DP 2–9, total polymers and total PACs in cranberries and cranberry products. Cranberry proanthocyanidin (PAC) oligomers and total polymers were isolated from cranberry juice concentrate, and the oligomers with degree of polymerization (DP) 3‐9 were characterized by UPLC‐HRMS. A normal phase HPLC method to quantify cranberry PACs was established by using the relative response factors that were developed specifically for cranberry PAC oligomers (DP 2‐9) and total polymers. This method was further validated to assess LOD, LOQ, the linearity and working range, precision and accuracy.