Novel Functionalities of Mixed Polysaccharides. Dr Tim Foster

Transcription

1 Novel Functionalities of Mixed Polysaccharides Dr Tim Foster

2 Acknowledgements Mita Lad Rebecca Schofield Amir Abbaszadeh Charlie Winkworth-Smith John Mitchell

3 Particulate Systems 25µm 50 µm

4 Effect of Shear during Gelation: Fluid gel Particle formation Composite properties are dependent upon the number and size of particles produced. This in turn is dependent upon the polymer used, the polymer concentration and the shear field. Developed for fat or xanthan A B replacement G'(Pa) 1,000, ,000 Storage Modulus of Agar Gels Formed Quiescently and Under Shear Measurement Temperature = 10C Quiescent Sheared 10,000 1,000 SPREADABLE 100 SPOONABLE POURABLE [Agar] 35C Temperature

5 Novel Functionalities of Mixed Thickening upon dilution Polysaccharides Mixed systems for human digestion Next Generation Phase Separation Synergism New Understanding New Opportunities

6 Hydrocolloid Materials & Function - Gelling Pectin Alginate Starch Agar Carrageenan Gellan Curdlan Celluosics Succinoglycan Scleroglucan Mixtures - Thickening - Emulsification Pectin Gum Arabic Alginate Propylene glycol Alginate Starch Sugarbeet pectin LBG OSA starch Guar Gum Xanthan lamda Carrageenan Cellulosics Beta Glucan

7 Ice Cream Milk Protein LBG Air Ice

8 Mixed Biopolymers

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10 Novel Functionalities of Mixed Thickening upon dilution Polysaccharides Mixed systems for human digestion Next Generation Phase Separation Synergism New Understanding New Opportunities

11 Hydration of Xanthan in the presence of CWS Starch Viscosity (cp) % Ultratex 4 1% Xanthan 3.5% Ultratex % Xanthan 3.5% Ultratex % Xanthan Time (secs) Competition for water as xanthan and CWS hydrate Behaviour dominated by one or the other depending on the ratio of biopolymers.

12 Creation of new structures through understanding phase behaviour Polarised Light Microscopy 1% Xanthan 5% Polyacrylate 80 um

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14 Final viscosity of the different hydrocolloid mixtures High Mw KM

15 Final viscosity of the different hydrocolloid mixtures High Mw KM

16 Viscosity / cp % Starch (UT2) + 2% Xanthan (initial make up in water) + 20% Dilution (with water) 10% Starch (UT2) + 2% Xanthan (initial make up in water) + 20% Dilution (with HCl ph 2.5) % Starch (UT2) + 2% Xanthan (initial make up in water) + 20% Dilution (with 0.1 M NaCl) Time / s

17 Viscosity / cp % Starch (UT2) + 2% Xanthan (initial make up in 0.1M NaCl) + 20% Dilution (with water) 10% Starch (UT2) + 2% Xanthan (initial make up in 0.2 M NaCl) + 20% Dilution (with water) % Starch (UT2) + 2% Xanthan (initial make up in citric biffer ph 4.2) + 20% Dilution (with water) Time / s

18 % UT2 + 2% Xanthan (initial make up in water) + 20% Dilution (with water) % UT2 + 2% Xanthan (initial make up in water) + 20% Dilution (with acid HCl ph 2.5) 10% UT2 + 2% Xanthan (initial make up in water) + 20% Dilution (with 0.1 M NaCl) % UT2 + 2% Xanthan (initial make up in 0.1M NaCl) + 20% Dilution (with water) 10% UT2 + 2% Xanthan (initial make up in 0.2M NaCl) + 20% Dilution (with water) % UT2 + 2% Xanthan (initial make up in citric acid ph 4.2) + 20% Dilution (with water) After dilution Before dilution

19 Dilution Results HPC Low Mw KM All at 2% hydrocolloid 10% starch Blue = 10% dilution Red = 20% dilution High Mw KM

20 Creation of new structures through understanding phase behaviour Polarised Light Microscopy 1% Xanthan 5% Polyacrylate CSLM 2% Xanthan 10% Starch Properties also seen for other swellable particles e.g. plant cell materials (citrus fibre), swellable gel particles and porridge oats.

21 Satiating Porridge? % oats + 2% xanthan sigma + 5% oil 25C % oats + 2% xanthan sigma + 5% oil 50C % Xanthan 5% Oil only 25C % Oats only + 5% Oil 25C % oats + 2% xanthan sigma + 5% oil 50C + 10% dilution 37C % oats + 5% oil 50C + 10% dilution 37C control

22 Point of dilution STRUCTURE RETENTION STRUCTURE CREATION Viscosity / cp um um Time / s

23 Novel Functionalities of Mixed Polysaccharides Thickening upon dilution Mixed systems for human digestion Next Generation Phase Separation Synergism New Understanding New Opportunities

24 In-Body Requirements for functional foods: Understanding the physics of food in the body environment How food structures change during digestion How food structures interact with body fluids Rates and amounts of these will influence the efficacy of the meal Food needs to be palatable, otherwise no one will eat it, or come back and eat it again!!

25 Other methods of lowering viscosity The viscosity of KM was reduced when mixed with maltodextrin The lower the DE of the maltodextrin the greater the reduction in viscosity Point of addition did not make a difference. 2% KM, 10% Maltodextrin added after 15 mins 2% KM, 0% Maltodextrin DE 5

26 Can this be achieved from Designed Microstructures? LBG (WT%) % LBG / 25% PR 50% LBG / 50% PR 0.6 * 0.4 * 0.2 * 25% LBG / 75% PR MICELLAR CASEIN (WT%) Phase diagram measured at 5C 18 20

27 Results Acidification Protein continuous microstructure (75% Φ SMP: 25% Φ guar) nominal concentrations (30%: 0.15%) Original mixture ph6 ph 3 ph 2 Polysaccharide continuous microstructure (75% Φ guar: 25% Φ SMP) - nominal concentrations (0.45%:10%) Original mixture ph 6 ph 5 ph 2

28 Results - Digestion Protein continuous microstructure (75% SMP: 25% guar gum) Original ph 2 + pepsin 2 hrs 4 hrs Polysaccharide continuous microstructure (75% guar gum: 25% SMP) Original ph 2 + pepsin 2 hrs 4 hrs

29 Digestion - protein/ polysaccharide/ oil system Polysaccharide continuous microstructure (75% guar gum: 25% SMP + 5% oil) Original mixture 60 min ph2 + pepsin 120 min 30 min 240 min

30 Novel Functionalities of Mixed Polysaccharides Thickening upon dilution Mixed systems for human digestion Next Generation Phase Separation Synergism New Understanding New Opportunities

31 2 mins 16 mins 25.5 % Sugar, 31.4% Glucose syrup, 7% Gelatin, 4% Oxidised Starch and 0.7% polystyrene latex particles

32 Carrageenans Separated by the prefix A B C Confocal laser scanning micrographs of 1.125% i-carrageenan mixed with a) 1.5% k carrageenan, b) 1% k-carrageenan and c) 0.75% k-carrageenan. In 0.4M NaCl. Scale bar=10mm. Lundin LO, Odic K and Foster TJ, Phase Separation in Mixed Carrageenan Systems, Proceedings to Supermolecular and Colloidal Structures in Biomaterials and Biosubstrates, Mysore, India, 1999.

33 Novel Functionalities of Mixed Polysaccharides Thickening upon dilution Mixed systems for human digestion Next Generation Phase Separation Synergism New Understanding New Opportunities

34 Coupled Interactions - Synergism T -S w e e p 10 3 Pa 10 G' G '' K M ( R S ) + X a n t h a n S a n d a rd A / H ig h P K M (R S ) + X a n th a n S ta n d a rd K M (R S ) + X a n th a n S ta n d a rd A / L o w P T e m p e ra tu re T A n to n P a a r G m b H C 100

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37 Polysaccharide Interactions Xanthan as a cellulose model Binding of hemicelluloses to xanthan Binding of hemis and xanthan to CELLULOSE

38 Novel Functionalities of Mixed Polysaccharides Thickening upon dilution New Processing and Nutritional opportunities Mixed systems for human digestion New ways to control structure change in the body Next Generation Phase Separation New textures Synergism Building natural composite structures New Understanding New Opportunities