10 research outputs found
Volatile compounds, sensory quality and ice morphology in falling-film and block freeze concentration of coffee extract
Coffee extract was freeze-concentrated through block and falling-film techniques. Solute retention and
concentration efficiency were determined after one stage of these processes. Ice morphology was characterized
through image analysis. Preservation of volatile compounds was determined through GC–MS.
The effect of coffee extract on flavour was determined after freeze concentration through sensory evaluation.
Solute occlusion was higher for falling-film than for block freeze-concentration, with an average
distribution coefficient of 0.45 and 0.29, respectively. The ice crystal size was lower for the falling-film
technique; this explains the higher solute occlusion. The dewatering capacity was higher for the
falling-film technique, as this process is faster than block freeze-concentration. The most abundant volatile
compounds of the coffee extracts were preserved after freeze concentration with both techniques. In
the same way, no differences were found in most of the sensory attributes of the freeze-concentrated
extract obtained using both techniques. Our results confirm the benefits of the block and falling-film
freeze concentration techniques in preserving the quality of coffee extracts.Postprint (author's final draft
Volatile compounds, sensory quality and ice morphology in falling-film and block freeze concentration of coffee extract
Coffee extract was freeze-concentrated through block and falling-film techniques. Solute retention and
concentration efficiency were determined after one stage of these processes. Ice morphology was characterized
through image analysis. Preservation of volatile compounds was determined through GC–MS.
The effect of coffee extract on flavour was determined after freeze concentration through sensory evaluation.
Solute occlusion was higher for falling-film than for block freeze-concentration, with an average
distribution coefficient of 0.45 and 0.29, respectively. The ice crystal size was lower for the falling-film
technique; this explains the higher solute occlusion. The dewatering capacity was higher for the
falling-film technique, as this process is faster than block freeze-concentration. The most abundant volatile
compounds of the coffee extracts were preserved after freeze concentration with both techniques. In
the same way, no differences were found in most of the sensory attributes of the freeze-concentrated
extract obtained using both techniques. Our results confirm the benefits of the block and falling-film
freeze concentration techniques in preserving the quality of coffee extracts