Milling
Dehulled faba beans were milled by different methods to achieve flours for different analyses. Pin-disc milling: seeds were
milled using a laboratory pin-disc mill (KT-30, Koneteollisuus Oy,Finland) set up to achieve its minimum pin-disc gap. After being milled once through the machine, the flours were labelled as “one-pass pin-milled flours”. The one-pass pin-milled flours were used for particle size analysis in order to test the faba bean milling quality. Roller milling: The one-pass pin-milled flours were milled twice more by the pin-disc mill and then further milled using a roller mill (Brabender
® Quadrumat
® Junior) to produce “roller-
milled flours”. Most grain flours sold in food markets are produced
by roller-milling methods. Therefore, the roller-milled flours were
used for protein extraction measurement, microstructure obser-
vation and pasting property analysis in order to evaluate their food-
use functionalities. Ultra-centrifugal milling: Part of the seeds
were milled using a high speed rotor ultra-centrifugal mill (Ultra
Centrifugal Mill ZM 200, Retsch, Germany) equipped with a ring
sieve having a pore size of 0.5 mm. The rotation speed was
12000 rpm. The flours were then collected and marked as “ultra-
centrifugal milled flours”. Ultra-centrifugal milling produces fine
flours with an even particle size distribution, which are commonly
used in chemical compound analyses. In this study, the ultra-
centrifugal milled flours were used for the peroxidase activity
assay, lipoxygenase activity assay and volatile compound charac-
terization. Replication of milling and dividing were described in
each section.