Systematic study on active compounds as antibacterial and antibiofilm agent in aging onions

Publication date: April 2018Source: Journal of Food and Drug Analysis, Volume 26, Issue 2Author(s): Kavita Sharma, Neelima Mahato, Yong Rok LeeAbstractQuantitative investigation and systematic studies of quercetin, total phenolics, flavonoids, antioxidants, antibacterial and antibiofilm or antibiofouling properties of methanolic extracts of onions obtained from six different varieties have been carried out to explore their relative merits in terms of biological activities of fresh and aging onions. Total phenolic content in the extracts was examined spectrophotometrically using Folin–Ciocalteau's phenol reagent and total antioxidant activity was studied by FRAP and DPPH methods. In vitro antibacterial activity of the extracts was investigated on Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus cereus) respectively, by using a modified Kirby–Bauer disc diffusion method. Antibiofilm activity was tested by crystal violet assay. The best results against biofilm formation were observed for the extracts obtained from onions stored for three months. The total phenolic and antioxidant content found to be increased upon aging in all the six varieties; red skinned onion (Happyhong) showed the highest level of total phenolics (5110.07 ± 196.56 μg GAEg−1 FW) and total flavonoids (2254.00 ± 154.82 μg QEg−1 FW) after three months. The results showed that in all the varieties, quercetin content as well as bi...
Source: Journal of Food and Drug Analysis - Category: Food Science Source Type: research