FCT (Fundação para a Ciência e Tecnologia), através do Projeto PTDC/AGR-ALI/68284/2006.
The main aim of the present work was to optimize mead production using Response Surface Methodology. The effects of temperature (x1: 20–30 ºC) and nutrients concentration (x2: 60–120 g/hL) on mead
quality, concerning the final concentrations of glucose (Y1), fructose (Y2), ethanol (Y3), glycerol (Y4) and acetic acid (Y5), were studied. Twelve operational conditions were tested. No delays and moods were
observed during fermentations. The second order polynomial models determined produced satisfactory fittings of the experimental data with regard to glucose (R2= 0.646, p = 0.001), ethanol (R2= 0.741,p = 0.049), glycerol (R2= 0.899, p = 0.002), fructose (R2= 0.902, p = 0.033) and acetic acid (R2= 0.913,p = 0.001). The optimum extraction conditions determined in order to maximize the combined responses were 24 ºC and a nutrients concentration of 0.88 g/L. The mead produced under these conditions had the
following characteristics: ethanol concentration of 10.2%, acetic acid 0.54 g/L, glycerol 7.8 g/L, glucose
1.8 g/L and fructose 2.5 g/L. These values were in agreement with the predicted and were within the safe limit established for acetic acid and the recommended range for glycerol. Furthermore, the residual sug-
ars concentration was also low, decreasing the possibility of occurring undesirable refermentations.
