Seaweed based antioxidants analysis and application

Transcription

1 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

2 Background Omega 3 Cells: Part of the cell membrane Membrane-flexibility Function: Sight Brain Heart and blood Sperm quality

3 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

4 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)

5 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± Acetone, AcE 23.2± Ethanol, EtE 20.4± *IC10 (EAF) = Ethyl acetate, EAF 26.5± ND*

6 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: mg

7 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: % loss Milk added WE: % loss Milk added EAF: % loss +WE or EAF Formation of primary oxidation products and secondary oxidation products Time (d) +EAF +WE REF Time (d) REF +EAF +WE

8 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

9 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 WE, AcE, EtE or EAF +WE REF +EAF +AcE +EtE REF +WE EAF +EtE +AcE Storage time [days] Storage time [days]

10 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

11 PV [meq O2/kg] 1-Penten-3-one [ng/g] Results - Granola bars Formation of primary oxidation products and secondary oxidation products WE, AcE or EtE +WE REF +AcE, EtE REF +WE +AcE, EtE Storage time [week] Storage time [week]

12 Results Granola bars Microstructure Oil droplet Oil pool Control Oil pool Water extract Acetone extract Ethanol extract

13 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

14 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

15 Acknowledgement

16 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: /j.jff 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