Maillard reaction development is generally monitored by the increase in the
absorbance either at 280 (early MRPs), which is considered to indicate formation of furfural
compounds and is used to detect products of early stage of browning. Furthermore, the
degree of browning or browning intensity (BI), usually measured via absorbance at 420 nm,
is often used to follow the extent of the Maillard reaction (brown pigments or melanoidins).