The influence of roasting and additional processing on the content of bioactive components in special purpose coffees.

ABSTRACT: Coffee being the beverage consumed worldwide is also a very competitive commodity. Consequently, producers seek ways of attracting consumers by proposing e.g. novel ingredient combinations usually without evaluating their health quality. In this study, variations in health-promoting determinants for five special purpose coffee brews were characterized. The major bioactive components - chlorogenic acids (CAs) - detected by HPLC-DAD-MS included caffeoyl-, feruloyl- and dicaffeoylquinic acids. Roasting declined CAs content by 50 %, while caffeine content increased by about 30 % during this process. In roasted coffee brews studied, CAs content varied from 14.1 to 26.6 mg/g; smaller variations were seen in antioxidant potential (determined by spectrophotometric and cyclic voltammetry assays). Profiles generated by HPLC with post-column on-line antioxidant detection revealed that caffeoylquinic acids were the most abundant antioxidants in samples studied. The highest antioxidative potential exhibited coffee enriched with green coffee extract confirming the soundness of such an approach to obtain healthier products. HIGHLIGHTS: • Special purpose coffees are equivalent to regular ones as regards antioxidant potential. • Caffeoylquinic acids are the most abundant antioxidants in coffee samples studied. • Roasting process causes some degradation of chlorogenic acids but not caffeine. • Special purpose coffees retain health benefits while being more attractive to consumers.