Rapeseed pomace as a source of bioactives for health

Transcription

1 Rapeseed pomace as a source of bioactives for health Dr. Giovanna Bermano Director, Centre for Obesity Research and Education (CORE) Co-Director, Centre of Natural Products for Health (CNP) Rapeseed Pomace Brassica napus

2 Content Introduction to Rapeseed and Rapeseed Pomace (RSP) Previous work on RPS Preliminary results from HVCfP Business Innovation Voucher in collaboration with Advanced Microwave Technologies Ltd Assessment and optimisation of microwave-assisted extraction of bioactive and bio-available compounds from rapeseed pomace

3 Rapeseed (Brassica napus) One of the world s major oil seeds 3 rd largest source for vegetable oil for human consumption Used as biodiesel for cars and agricultural machines Food source for animals Produced mainly by - Austria, Canada, China, Czech Republic, Denmark, France, Germany, India, Poland & UK - 3 rd biggest crop grown in Scotland McKeith, 2005 British Nutrition Foundation Nutrition Bulletin USDA ( FAOStat Food and Agricultural Organisation of the United Nations (

4 Rapeseed: what is obtained? Rapeseeds Rapeseed Pomace Rapeseed Oil 35M tones

5 Rapeseed oil Favourable balance of good and bad fats Only 7% saturated fat <50% lower than olive/sunflower oil Healthier alternative Rich in healthy mono-unsaturated and poly-unsaturated fats Omega 3 (10x), 6 and 9 Cholesterol and inflammation reducing properties Vitamin E Powerful antioxidant Glucosinolates Anticarcinogenic

6 Rapeseed Pomace (RSP) Waste product, 35 million tons produced per year worldwide Used as supplement for chicken and calf feed Little work to establish the health benefits to humans Could RSP be a source of valuable bioactives for health? Scottish producers are beginning to recognise and exploit the superior potential of cold-pressed quality virgin rapeseed oil Preliminary work has been carried out in collaboration MacKintosh of Glendaveny, Peterhead, Scotland

7 Previous/current work A study on the anti-oxidant and DNA protective properties (in vitro) of a RSP extract and its effects in a C. elegans model for neurodegenerative disease An in vitro study on the anti-cancer properties of rapeseed pomace extracts

8 RSP Extraction Soxhlet Extraction Samples defatted with petroleum ether (150 C) Extraction with Ethanol-Water (95:5) at 240 C followed by evaporation cycles and rising cycles Last evaporation cycle aborted before dryness extract evaporated on rotary evaporator, freeze dried, resuspended in EtOH-H 2 O (4:10), diluted further in dh 2 O Accelerated Solvent Extraction (ASE) Ethanol-Water (3 different ratios 80:20, 50:50, 20:80) at 80 C under high pressure The solvent is then evaporated on a GenVac, at ~60 C under vacuum before resuspending in dh 2 O

9 DPPH Free Radical Scavenging Ability (%) Free radical scavenging activity (DPPH Assay) Soxhlet Extraction Accelerated Solvent Extraction (ASE) 50 EtOH:50 dh2o 80 EtOH:20 dh2o 20 EtOH:80 dh2o * RSP Extract concentration (mg/ml) Free radical scavenging capacity (%) of RSP extracts, rapeseed oil and quercetin all at 1.5mg/mL, n=3 Similar scavenging activity from the 2 extraction methods Free radical scavenging ability (%) of the 3 different RSP extracts, mean ± sem, *p<0.05, **p<0.01 and ***p<0.001 compared to mg/ml, n=3 DPPH = 2,2-Diphenyl-1-picrylhydrazyl

10 Phenolic content (Folin Ciocalteu Assay) Soxhlet Extraction Accelerated Solvent Extraction (ASE) RSP Extract GAE ± sem (mg/ g dry weight RSP) Extract ± 1.7 Extract ± 1.0 Amount of Gallic Acid Equivalent (mg) for 1g of RSP (dry weight) RSP Extract GAE ± sem (mg/100 g dry weight RSP) 50 EtOH: 50 dh 2 O ± EtOH: 20 dh 2 O 9.57 ± EtOH: 80 dh 2 O ± 6.04 Amount of Gallic Acid Equivalent (mg) for 100 g of RSP (dry weight) Higher Phenolic content in extracts from Soxhlet extraction (100 times) compared to ASE Gallic acid equivalent in mg/ml found in the 3 different RSP extracts, mean±sem, *p<0.05 and **p<0.01 compared to each control, n=3.

11 Chemical Profile (Metabolites - LC-MS/MS) Components (µg/ml) Pomace Oil Components (µg/ml) Pomace Oil sinapic acid p-anisic acid hydroxy-3,5- benzoic acid dimethoxyacetophenone ferulic acid naringenin syringic acid indole-3-acetic acid cinnamic acid kaempferol vanillic acid anthranilic acid indole-3-carboxylic acid hydroxy-3-methoxyacetophenone syringin ,8-dihydroxy-6-methyl coumarin phenylacetic acid bergapten vanillin luteolinidin phenyllactic acid hydroxycinnamyl alcohol isorhamnetin tangeretin Apigenin ,4,5-trimethoxyacetophenone metabolites in RSP 26 metabolites in rapeseed oil

12 HVCfP Business Innovation Voucher Rapeseed Pomace high yield/low value products low yield/high value product Biomass valorisation Sustainable and scalable production of naturally derived bioactives AIM to test microwave-assisted extraction to isolate bioactive compounds for nutraceutical, pharmaceutical or cosmetic product use Extracting straight into water Tight temperature control to prevent thermal degradation

13 The Approach Microwave-assisted extraction Analyses Desk top (batch) Proof of concept (continuous flow) Benefits Tight temperature control to prevent thermal degradation Extracting straight into water

14 Preliminary results Batch testing Temperature Retention time Weight percent solids Temp Solid left over Retention time at temperature Solids weight percent Pressure ( o C) (min) Wt.% (bar) Extract Before After Extract after filtration

15 DPPH Free Radical Scavenging Ability (%) Gallic Acid Equivalent (mg/ml) Preliminary results - Batch testing DPPH Assay FC Assay Temperature Retention time Solid Weight % Free radical scavenging ability (%) of the different RSP extracts diluted 1:25 Temperature Retention time Solid Weight % Gallic acid equivalent (mg/ml) in the different RSP extracts diluted 1:10 Scavenging activity is not affected by temperature Solid weight % above 10% does not increase activity Phenolic content is not affected by temperature Phenolic content increases with solid weight % used

16 Conclusions Results are encouraging so far for this proof of concept project Free radical scavenging activity 50% was found in most of the AM extracts, at the dilution tested, in contrast to the Soxhlet and ASE extracts Similar phenolic content was found in some of the AM extracts (e.g % solid weight) to ASE extracts tested However.it is not possible to convert the values obtained to grams of dry weight extract making difficult, at this stage, to compare results with values in the literature Next steps: Scale up extraction on continuous flow machine Test extracts samples and left over products

17 Acknowledgements Professor Cherry Wainwright Ms Hazel Ramage Ms Franziska Pohl Dr Gemma Barron Dr Marie Goua Professor Paul Kong Thoo Lin Mr Sam Kerr Mr Stephen Roe Mr Gregor Mackintosh