Aqueous acetone was the best solvent for extracting total
phenolics and antioxidants from lentil hulls with significantly higher
recoveries from red than green lentils. Antioxidant activity was
consistently maximally expressed in aqueous acetone extracts of the
whole, hull and residue of both green and red lentils. The total
phenolics of hot water extracts were generally higher than those
extracted with water probably due to their release from food matrix
resulting from structural breakdown or because of their thermal
instability (Ranilla, Genovese, & Lajolo, 2009). Hot water extracted the
most total phenolics from the whole lentils and their residue, but
displayed lower potent antioxidant activity than their respective
acetone extracts. Water extracts of lentil hulls exhibited high
antioxidant activity second only to their acetone extract, not reflecting
their modest total phenolic content. The antioxidant activity of green
lentil hull extracts segregated succinctly based on the extracting
solvent, whereas those from the red lentil hull showed no significant
difference between hot water and water extracts. This may result
from the greater ease [clean removal of the seed coat] of dehulling
green (with larger seed and thicker seed coat) than the small seeded
red lentils (therefore purer hull fraction).