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

Sensory properties of cocoa liquor roasted at 120 degreesC 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. (C) 2003 Elsevier Ltd. All rights reserved.