JuDong Yeo- August 3
Lentils serve as a valuable dietary source of protein, carbohydrate, minerals, vitamins, and dietary fibre, thus provide essential nutrients to different populations around the world, especially the vegetarians. In the present study, effects of hydrothermal processing and dehulling on the antioxidant capacity of soluble- and insoluble-bound phenolics of lentils were examined as well as bioactivities such as inhibitory activity against α-glucosidase and oxidation of LDL cholesterol and DNA strand breakage. The hydrothermal processing (boiling) led to very interesting results in which insoluble-bound phenolics were released from the cell wall matrices. Interestingly, the decrease in the content of bound phenolics was not reflected in the increase in soluble phenolics, possibly due to the loss of phenolics due to their combination with proteins and other seed components. Dehulling process revealed the predominant distribution of phenolics in the hulls as compared to the dehulled grains; as observed for both soluble- and insoluble-bound phenolics. The corresponding effects on the antioxidant potential and inhibitory activities against α-glucosidase activity and oxidation of LDL cholesterol and DNA strand breakage also reflected much higher effects in the hulls compared to those of the dehulled as well as whole seeds. In the HPLC-ESI-MSn analysis, different classes of soluble phenolics such as phenolic acids, flavonoids, and proanthocyarndins were found in the hulls of all tested lentil cultivars. Insoluble-bound phenolics displayed a relatively few number of peaks than their corresponding soluble phenolics.