Effect of dual modification of sonication and γ-irradiation on physicochemical and functional properties of lentil ( Lens culinaris L.) starch

Starch isolated from lentil was subjected to two treatments namely sonication and, a dual treatment of sonication and irradiation at a dose of 5 kGy. Lentil yielded 26.12 ± 1.56 g starch/100 g of lentil. Chemical composition of native starch revealed 7.83 ± 0.28% moisture, 0.23 ± 0.30% protein, 0.35 ± 0.05% fat and 0.10 ± 0.00% ash. The results revealed that pasting properties of lentil starch were not affected upon sonication. However, these decreased significantly (p ≤ 0.05) upon dual treatments. Amylose content of native starch was 31.16 ± 1.80 g/100 g which showed a decrease upon sonication and dual treatments. Sonication and dual treatments (sonication and irradiation) decreased hunter ‘L’ value while ‘a’ and ‘b’ values showed an increase. Syneresis decreased more or less insignificantly upon sonication. However, a significant decrease in syneresis was observed after 120 h storage following dual treatments. Sonication did not decrease the functional properties significantly while as dual treatment induced a significant decrease in functional properties. FT-IR analysis revealed a decrease in the intensities of O H, C H and O C stretches and CH2 bending upon sonication and dual treatments.