Itwas previously shown that by the activity of yeast,HMF in fermentation medium is converted into hydroxymethylfurfuryl alcohol (HMF alcohol) (Akıllıoglu et al., 2011). The conversion of HMF into HMF alcohol was monitored in samples during fermentation (Fig. 1b). 63% of 307.42 mg/L HMF in the fermentation medium at the beginning was converted into HMF alcohol at the end of the 24 h of fermentation of the non-sugar containing sample. 201.1 mg/L, 199.8 mg/L, and 184.4 mg/L HMF alcohol were formed at the end of the fermentation in 1, 5, and 10% sucrose containing media, respectively. The first order formation kinetic model fitting parameters are given in Table 1. The effect of sucrose concentration was not statistically important for the HMF alcohol content formed (p N 0.05). However, therewas a slight decrease in the conversion of HMF (60% conversion)when the concentration of sucrose was raised to 10%. This could be explained by the accumulation of HMF alcohol in the fermentationmediumor by the accumulation of other reaction products causing a slight inhibition effect. The fermentation experiments were also performedwith 2% yeast inocula under similar conditions. The same trend in the HMF degradation rate and HMF alcohol conversion was obtained (figure not shown). The degradation rate increased by a factor of 2.6 when sucrose concentration was raised from 1% to 5%, however, it decreased when sucrose concentration was raised to 10% (p b 0.05) (Table 1). The amount of HMF alcohol formed at the end of the fermentation decreased with the increment of sucrose content. This may be attributed to the higher accumulation rate of fermentation products in the presence of higher yeast inocula. To the best of our knowledge, there is no HMF degradation data in coffee by means of yeast fermentation.