3. Results and discussion
3.1. Acetone extract
The sifted hull residue represented 23, 20.1, and 12.5% (w/w) of
red lentil, green lentil, and yellow pea hull fractions, respectively. The
amount of red lentil residue (23%) was similar to that reported
previously (Wang, 2008) in dehulling Canadian red lentil varieties
indicating significant removal of cotyledons through this process.
Pulse hulls had significantly (Pb0.0001) higher concentration of total
phenolic and phenolic components than their corresponding whole
seeds or residue when extracted with aqueous acetone (Table 1).
Total phenolic content of lentil hulls were seven (red) to eight (green)
times those in their whole seeds, whereas tartaric esters and
anthocyanin contents were three to four folds the concentration in
seeds. Furthermore, the total phenolic content of all red lentil acetone
extracts were significantly (Pb0.0001) higher than those of the
corresponding green lentil extracts. Differences in content of phenolic
components of acetone extracts between red and green lentils were
significant (Pb0.0001) in hull, and residue. However, this difference
was not significant when comparing extracts of whole red and green
lentils, except for total phenolics. The difference in anthocyanin
content and antioxidant activity between whole seed and residue
extracts of red and green lentils were also not significant.