Seaweed based antioxidants analysis and application Ditte B Hermund, PhD student Rósa Jónsdóttir and Hordur G Kristinsson, Matís, Iceland Charlotte Jacobsen and Kristian F Nielsen, DTU, Denmark
Background Omega 3 Cells: Part of the cell membrane Membrane-flexibility Function: Sight Brain Heart and blood Sperm quality
Aim and objectives Extraction, identification and characterization bioactive compounds Polyphenolic compounds Fucus vesiculosus Fucodiphlorethol E. (Wang et al. 2012) [M-H] - at m/z 497 = 4 PGUs
Lipids Light, heat, metal ions Free lipid radical Metal chelator O2 Radical scavenger Peroxides Metal ions Rancid smell and taste Secondary oxidation products (alcohols, acids, aldehydes, ketones)
Crude extracts and fraction Phenolic compounds and Antioxidant activity Antioxidant activity Crude extract Solvent fraction TPC (mg GAE/100 g dry CE or SF) Radical scavenging (DPPH) IC50 (mg Dw/mL) Metal chelating IC50 (mg Dw/mL) Water, WE 18.4±0.1 0.046 0.640 Acetone, AcE 23.2±1.1 0.021 1.279 Ethanol, EtE 20.4±2.4 0.017 1.092 *IC10 (EAF) = 1.108 Ethyl acetate, EAF 26.5±1.2 0.007 ND*
Applications Fish-oil-enriched food products Oil-in-water (o/w) emulsions 5% FO enriched milk Concentrations: 1, 1.5 and 2 g/kg milk 15% FO enriched mayonnaise Concentration: 1.5 g/kg mayonnaise 5% FO enriched granola bars Concentrations: 0.5 and 1 g/kg granola bar 5% Fish oil enrichment 100g portion ~ 5g FO ~ 500mg EPA+DHA RDI: 300-500mg
Peroxide value [meq/kg oil] 1-penten-3-ol [ng/g milk] Results - 5% FO-enriched milk Loss of EPA and DHA during storage REF without added seaweed extract: 3.9-5.4% loss Milk added WE: 0.9-1.5% loss Milk added EAF: 0.3-0.6% loss +WE or EAF Formation of primary oxidation products and secondary oxidation products 20 18 16 14 12 10 8 6 4 2 0 0 1 2 3 4 5 6 7 8 9 10 11 12 Time (d) +EAF +WE REF 70 60 50 40 30 20 10 0 0 1 2 3 4 5 6 7 8 9 10 11 12 Time (d) REF +EAF +WE
Concluding marks - Milk The addition of extracts from F. vesiculosus resulted in: Reduced loss of EPA and DHA during Lower formation of secondary oxidation products The antioxidant efficiency of the extracts/fraction was depending on high TPC and high radical scavenging capacity However: Addition of extract or fraction showed high initial PV Difficult to monitor the oxidation parameters Some prooxidant activity was observed
PV [meq O2/kg olie] 1-penten-3-ol [ng/g mayonnaise] Results - 15% FO-enriched mayonnaise Formation of primary oxidation products and secondary oxidation products 8 7 6 5 4 +WE, AcE, EtE or EAF +WE REF +EAF +AcE +EtE 300 250 200 150 REF +WE 3 2 1 100 50 +EAF +EtE +AcE 0 0 4 8 12 16 20 24 28 Storage time [days] 0 0 4 8 12 16 20 24 28 Storage time [days]
Concluding marks - Mayonnaise The addition of extracts from F. vesiculosus resulted in: Reduced amount of primary oxidation products Lower formation of secondary oxidation products High antioxidant efficiency of the extracts/fraction was related to high TPC, high radical scavenging capacity and a moderate metal chelating ability
PV [meq O2/kg] 1-Penten-3-one [ng/g] Results - Granola bars Formation of primary oxidation products and secondary oxidation products 40 35 30 25 20 15 +WE, AcE or EtE +WE REF +AcE, EtE 35 30 25 20 15 REF +WE +AcE, EtE 10 10 5 5 0 0 1 2 3 4 5 6 7 8 9 10 Storage time [week] 0 0 1 2 3 4 5 6 7 8 9 10 Storage time [week]
Results Granola bars Microstructure Oil droplet Oil pool Control Oil pool Water extract Acetone extract Ethanol extract
Concluding marks Granola bars Overall the acetone and ethanol extracts showed highest antioxidant activity towards limiting oxidation in fish-oil-enriched granola bars since: Increased the lag phase of secondary oxidation products After 9 weeks of storage lower level of secondary oxidation products compared to the control High antioxidant efficiency was related to high TPC, high radical scavenging capacity. Moreover, ethanol and acetone extracts were related to improved emulsion structure in the bars
Potential, V Future work Identification and characterization of polyphenolic compounds HPLC and LC MS/MS On-line antioxidant activity by ECD 0,0175 LC 0,0125 ECD 0,0075 0,0025 Time, min
Acknowledgement
Thank you! Papers D B Hermund, B Yesiltas, P Honold, R Jónsdóttir, H G Kristinsson & C Jacobsen (2015): Characterisation and antioxidantevaluation of Icelandic F.vesiculosus extracts in vitro and in fish-oil-enriched milk and mayonnaise. Journal of Functional Foods, doi: 10.1016/j.jff.2015.02.020 P Honold, C Jacobsen, R Jònsdòttir, H G Kristinsson & D B Hermund: Seaweed based food ingredients to inhibit lipid oxidation in fish-oil-enriched mayonnaise. In press A Karadağ, D B Hermund, L H Søgaard Jensen, U Andersen, R Jónsdóttir, H G Kristinsson, C Jacobsen: The effect of novel brown seaweed based antioxidants on the oxidative stability and microstructure of 5% fish-oil-enriched granola bars. Submitted