Sensory properties of cocoa liquor as affected by polyphenol concentration and duration of roasting

Abstract

Sensory properties of cocoa liquor roasted at 120 °C for 15, 25, 35 and 45 min and containing different polyphenol concentrations (58, 116, 143 and 170 g kg −1) were studied. Eight trained panellists carried out the sensory analysis using line scale with Ghanaian fermented cocoa liquor as a reference. The sensory attributes were cocoa flavour, astringency, bitterness, acidity/sourness, fruity/floral/bouquet, raw/green, smoky, mouldy/earthy and viscosity. Results of the study showed that as polyphenol concentration in cocoa liquor increased, cocoa flavour and viscosity decreased and astringency and bitterness increased; however, other sensory properties were not influenced by polyphenol concentration. An increase in roasting duration of cocoa liquors containing 58–143 g kg −1 polyphenol increased the flavour intensity; meanwhile that of contains 170 g kg −1 polyphenol, it was in vice versa. These findings indicated that cocoa polyphenol would cause negative effect on flavour properties, apart from its well-known benefit as preservative and antioxidant.