Values of browning index of roasted buckwheat groats, after
30 min of processing, did not significantly differ from the values
obtained for raw groats (Table 1). The longer times of roasting,
40 and 50 min, caused a significant increase, about 40%, of
browning compared to the raw material. The browning index
indicates the levels of melanoidins in food products, which represent
final products of the Maillard reaction. Zielin´ ski et al. (2012)
showed that long-term storage of ginger cake promoted the
formation of brown polymer precursors. During buckwheat
roasting, changes occur in water activity and this could induce
the formation of brown compounds as reported by Zielin´ ski et al.
(2009). These authors observed a 33–36% increase of the browning
index compared to the unroasted samples.