Onion peel residue was discarded as waste,though it was a good source of nutraceuticals like quercetin.In the present study,onion peel from the unexplored Bangalore rose onion variety was extracted for quercetin by us...Onion peel residue was discarded as waste,though it was a good source of nutraceuticals like quercetin.In the present study,onion peel from the unexplored Bangalore rose onion variety was extracted for quercetin by using different physical,and enzymatic treatments.Microwaves yielded highest quercetin(45.27 mg/g)compared to other physical treatments.Combination of three enzymes(pectinase,hemicellulase,and cellulase)with micro-wave treatment improved quercetin yields(107.48 mg/g)significantly.This technology was advantageous due to its minimal processing,and utilization of green solvent.Three enzymes yielded higher quercetin compared to two enzyme treatments,and combination of two enzymes yielded higher quercetin compared to single enzyme treatments.The 99.74%of quercetin was recovered from the extract after encapsulating the quercetin to casein.The recovered quercetin from rose onion peel showed two peaks at 256,and 372 nm in the UV-Vis spectrum,and the peak of recovered quercetin was matched with that of standard quercetin in the HPLC.The FTIR spectrum of rose onion peel quercetin showed characteristic peaks for phenolic-OH,-CH,-C=O,-C=C symmetric stretchings,-CH bending,-C-O-C stretching,and=CH bending.These peaks were matched closely with standard quercetin peaks.The IC_(50) value of rose onion peel quercetin with respect to DPPH radical scavenging was 7.43μM,and it was close to the IC_(50)(7.31μM)of standard quercetin.Rose onion peel quercetin could inhibit the growth of Listeria,and Salmonella spp.Microbial quality,and firmness of tomatoes was improved after coating with rose onion peel quercetin.展开更多
文摘Onion peel residue was discarded as waste,though it was a good source of nutraceuticals like quercetin.In the present study,onion peel from the unexplored Bangalore rose onion variety was extracted for quercetin by using different physical,and enzymatic treatments.Microwaves yielded highest quercetin(45.27 mg/g)compared to other physical treatments.Combination of three enzymes(pectinase,hemicellulase,and cellulase)with micro-wave treatment improved quercetin yields(107.48 mg/g)significantly.This technology was advantageous due to its minimal processing,and utilization of green solvent.Three enzymes yielded higher quercetin compared to two enzyme treatments,and combination of two enzymes yielded higher quercetin compared to single enzyme treatments.The 99.74%of quercetin was recovered from the extract after encapsulating the quercetin to casein.The recovered quercetin from rose onion peel showed two peaks at 256,and 372 nm in the UV-Vis spectrum,and the peak of recovered quercetin was matched with that of standard quercetin in the HPLC.The FTIR spectrum of rose onion peel quercetin showed characteristic peaks for phenolic-OH,-CH,-C=O,-C=C symmetric stretchings,-CH bending,-C-O-C stretching,and=CH bending.These peaks were matched closely with standard quercetin peaks.The IC_(50) value of rose onion peel quercetin with respect to DPPH radical scavenging was 7.43μM,and it was close to the IC_(50)(7.31μM)of standard quercetin.Rose onion peel quercetin could inhibit the growth of Listeria,and Salmonella spp.Microbial quality,and firmness of tomatoes was improved after coating with rose onion peel quercetin.
