Blanched bathua leaves: Influence on phytochemical and antioxidant properties

Abstract

The inclusion of underutilised bathua (Chenopodium album) leaves in diet provides noteworthy antioxidants. These leaves were subjected to 1, 2- and 3-min blanching and its methanol and aqueous extracts were screened for phytochemicals with no change even after 3 min blanching. A decrease of 65.13 and 47.13 % in total phenolic content of methanol and aqueous extracts respectively was observed with increase in blanching time from 0 to 3 min. The total flavonoid content without blanching in methanol extract was 271.76±0.20 RE and on blanching at 1, 2 and 3 min were 347.36±0.10, 357.32±0.10 and 203.54±0.30 RE respectively in the methanol extracts. The aqueous extracts for flavonoid content increased by 6.72% with increase in blanching time from 0 to 2 min and decreased by 25.43% with further increase of blanching time to 3 min. Thus, blanching beyond 2 min resulted in loss of flavonoids. The maximum ΔL value of -6.03 was observed for sample 0 and the least of -14.55 was for sample 3 indicating that the samples were less bright than control. The maximum Δa value of 20.06 was observed for sample 2 and the least for sample 3 with 16.28. The maximum Δb value of 13.63 was observed for sample 0 and least of 3.82 for sample 3. There was significant positive correlation for colour Δb value with TPC and TFC with ρ = 0.54 and 0.76 respectively in methanol extracts and with ρ = 0.95 and 0.74 respectively in aqueous extracts. The free radical scavenging activity with DPPH showed IC50 of 0.23 µg/ml for methanol extract and 0.46 µg/ml for aqueous extract without blanching. The IC50 for superoxide scavenging activity decreased by 40.0 and 22.0 % in the methanol and aqueous extracts respectively with increase in blanching time from 0 to 3 min indicating lesser antioxidant activity.