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Technological University Dublin

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Antioxidant activity

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Full-Text Articles in Food Processing

Degradation Kinetic Modelling Of Colour, Texture, Polyphenols And Antioxidant Capacity Of York Cabbage After Microwave Processing, Amit Jaiswal, Nissreen Abu-Ghannam Jan 2013

Degradation Kinetic Modelling Of Colour, Texture, Polyphenols And Antioxidant Capacity Of York Cabbage After Microwave Processing, Amit Jaiswal, Nissreen Abu-Ghannam

Articles

Vegetables as an essential component of the human diet usually undergo some type of processing before being consumed. In the present study, impact of microwave (MW) processing on various physiochemical properties of York cabbage was studied. York cabbage was processed at 400, 560 and 800W for 0 to 14 min with an increment of 2 min followed by a kinetic study for the degradation of polyphenols, flavonoids, antioxidant capacity, colour and texture were carried out. Results showed that MW processing leads to significant reductions in the texture, colour, polyphenols and antioxidant capacity. For all the MW processing power studied total …


An Assessment Of The Antioxidant And Antimicrobial Activity Of Six Species Of Edible Irish Seaweeds, Sabrina Cox, Nissreen Abu-Ghannam, Shilpi Gupta Apr 2010

An Assessment Of The Antioxidant And Antimicrobial Activity Of Six Species Of Edible Irish Seaweeds, Sabrina Cox, Nissreen Abu-Ghannam, Shilpi Gupta

Articles

Six species of edible Irish seaweeds; Laminaria digitata, Laminaria saccharina, Himanthalia elongata, Palmaria palmata, Chondrus crispus and Enteromorpha spirulina were screened for potential bioactivity. Extraction of secondary metabolites was carried out using different solvents to determine antioxidant and antimicrobial properties of the dried extracts. The total phenolic contents of dried methanolic extracts were significantly different (p < 0.05). H. elongata exhibited highest phenolic content at 151.3 mg GAE/g of seaweed extract and also had the highest DPPH scavenging activity (p < 0.05) with a 50% inhibition (EC50) level at 0.125μg/ml of extract. H. elongata also had the highest total tannin and total flavonoid contents (p < 0.05) of 38.34 mg CE/g and 42.5 mg QE/g, respectively. Antimicrobial activity was determined using a microtitre method which allowed detection of bacterial growth inhibition at low levels. All methanolic seaweed extracts inhibited the food spoilage and food pathogenic bacteria tested; Listeria monocytogenes, Salmonella abony, Enterococcus faecalis and Pseudomonas aeruginosa, except C. crispus extracts. It was found that dried methanolic extracts of red and green seaweeds had significantly lower antimicrobial activity than the brown species; H. elongata had the highest antimicrobial activity with up to 100% inhibition. In the studied work, the antimicrobial activity of red and green seaweed extracts significantly increased when ethanol and acetone were used as extraction solvents (p < 0.05). Inhibition of E. faecalis with C. crispus extracts increased from 39.28 to 100% when ethanol and acetone were applied as solvents.