Food-use of faba bean has been commonly limited by the unpleasant “beany flavour” that can be induced
by untreated beans. Pre-treatment of faba beans with microwave heating for different durations and with
conventional oven heating was investigated, in order to resolve the “beany flavour” problem. Heating the
seeds by microwave for 1.5 min at 950 W was found to be an optimum pre-treatment method that
effectively inactivated the endogenous peroxidase and lipoxygenase, which are responsible for the beany
flavour causation. In addition, the treatment improved the technological properties of the beans as it
decreased seed hardness, improved milling quality, and increased flour pasting viscosity. It slightly
decreased protein solubility, while heating with microwave for 2 min or longer decreased the protein
solubility more severely and decreased the flour pasting viscosity. Conventional oven heating at 170
C
for 30 min also inactivated the peroxidase and lipoxygenase. The microstructure of the particles in flour-
water-suspension was changed by both microwave and conventional oven heating methods, which
induced the formation of water-insoluble starch-protein aggregates. Microwave heating for 1.5 min
provided an excellent balance of improved milling properties, preserved protein solubility and mini-
mized activity of enzymes that are detrimental to product flavour.
suspended