Determination of Flavanol and Procyanidin (by Degree of Polymerization 1–10) Content of Chocolate, Cocoa Liquors, Powder(s), and Cocoa Flavanol Extracts by Normal Phase High-Performance Liquid Chromatography: Collaborative Study

Abstract

An international collaborative study was conducted on an HPLC method with fluorescent detection (FLD) for the determination of flavanols and procyanidins in materials containing chocolate and cocoa. The sum of the oligomeric fractions with degree of polymerization 1-10 was the determined content value. Sample materials included dark and milk chocolates, cocoa powder, cocoa liquors, and cocoa extracts. The content ranged from approximately 2 to 500 mg/g (defatted basis). Thirteen laboratories representing commercial, industrial, and academic institutions in six countries participated in the study. Fourteen samples were sent as blind duplicates to the collaborators. Results from 12 laboratories yielded repeatability relative standard deviation (RSDr) values that were below 10% for all materials analyzed, ranging from 4.17 to 9.61%. The reproducibility relative standard deviation (RSD(R)) values ranged from 5.03 to 12.9% for samples containing 8.07 to 484.7 mg/g. In one sample containing a low content of flavanols and procyanidins (approximately 2 mg/g), the RSD(R) was 17.68%. Based on these results, the method is recommended for Official First Action for the determination of flavanols and procyanidins in chocolate, cocoa liquors, powder(s), and cocoa extracts.

Green and Efficient Extraction Method to Determine Polyphenols in Cocoa and Cocoa Products

“…Thus, in this work, RRFs were used to achieve the quantification for these compounds due to the lack of commercial standards (see section BAnalysis of Procyanidins by HPLC with fluorescence detector^). The RRFs used were specific for this analytical method according to Robbins et al (2013Robbins et al ( , 2012. The results and chromatographic profile of cocoa procyanidins are shown in Table 3 and Fig.…”

“…Due to their structural diversity and complexity, the analytical methodology employed for the analysis of these compounds is based mainly upon DP instead of separation of individual compounds and specific isomers (Robbins et al 2009). Therefore, a normal-phase HPLC-FLD method using a HILIC column was carried out to accomplish the analysis of procyanidins with different degrees of polymerization (Robbins et al 2009;Robbins et al 2013;Robbins et al 2012). This method allowed the measurement of the large structural diversity of these compounds by oligomeric size.…”

“…Quantification of procyanidins with different degrees of polymerization (DP) was carried out according to Robbins et al (2012). They have developed a reliable, robust, and readily transferable method for the analysis and quantification of procyanidins with different DP in cocoa and cocoa products, allowing its broader implementation for the analysis of procyanidins in cocoa.…”

“…The concentration of DP 2 to 10 was calculated using the various RRFs according to Robbins et al (Robbins et al 2012) by the following equation:…”

A new food frequency questionnaire to assess chocolate and cocoa consumption

“…Chocolate products are commonly consumed in the human diet and, depending on their cocoa content, can represent an important source of polyphenols, mainly flavonoids [1]. In fact, cocoa contains more phenolic antioxidant compounds than tea or red wine [2].…”