Understanding the role of processing and formulation on RBW oleogel microstructure

Vincenzo di Bari Presentation outlook

1. World innovation trends for lipids

2. Oil structuring strategies: Ø TAGs: Fats Ø Non-TAGs: Oleogels

3. Formulation of RBW oleogels: Ø Understanding the thermomechanical behaviour Ø Engineering RBW oleogels

4. Key features of oleogels research 1. World innovation trends for lipids

Trend Driver Reduction in trans- & Nutrition – health saturated (≤10%) fats

Reduction in chemically Nutrition – health modified oils Natural Nutrition – health Reduction in animal fats Choices Sustainability

Reduction in palm oil and Sustainability fats in general Nutrition – health

Increase in PUFA content Nutrition – health Natural 2. Edible oil structuring strategies

Molecular Particles mechanisms dispersion

Image taken from: Pernetti et al. Soft Matter (2007) 12, 221-231. Molecular mechanisms to structure edible oils

Traditional: TAGs Fats Solid structure = f(building blocks) Novel: Non-TAGs Oleogels Fats: complex hierarchical structure of TAGs

Image taken from “Structure and functionality of edible fats”, Marangoni et al. Soft Matter, 2012, 8, 1275. Non-TAGs based approach to structure edible oils

Non-TAGs: Oleogels*

Novel routes to structure edible oils

Mechanisms & Functionality = f(building block)

*Organogels are called “Oleogels” when structuring to edible oils Bio-based: • plants • insects • marine animals

2 Image taken from: Patel, A, and Dewettinck, K (2015). Comparative evaluation of structured oil systems: oleogel, HPMC oleogel, and HIPE gel. Eur. J. Lipid Sci. Technol. 117, 000-000. Plant

• Natural plant hydrophobic compounds deposited outside the epidermal cells

• Complex mixture of fatty alcohols and acids, their esters, hydrocarbons, ketones, etc

• Considered to be among the most promising oleogelators6,7 Plant wax based oleogels

Wax Oil • Candelilla • Olive • Carnauba • Sunflower • Sunflower • Rice bran • Rice Bran • Rapeseed • Berry • Vegetable • Bee • Salad • Fruit Plant wax based oleogels

Wax Oil • Candelilla • Olive • Carnauba • Sunflower • Sunflower • Rice bran • Rice Bran • Rapeseed • Berry • Vegetable • Bee • Salad • Fruit Rice bran wax (RBW)

Rice Bran (7.6 x 107 tons/year)1

Extraction / Hexane

Crude

Degumming

Dewaxing RBW (5-8%) ~700,000 tons Neutralisation

Bleaching De-odorisation Rice Bran Oil

1: Friedman, M., Rice Brans, Rice Bran Oils, and Rice Hulls: Composition, Food and Industrial Uses, and Bioactivities in Humans, Animals, and Cells. J. Agric. Food Chem. 2013, 61, 10626−10641 Rice bran wax (RBW)

• By-product

• Available in large volumes

• Promising gelling agent

• Temperature of phase transition compatible with pasteurisation

• In food applications Rice Bran Wax is EU regulated as a E908. RBW: structural levels

A

Macroscale Mesoscale

Nanoscale

Molecular

Wax ester

A Image taken from reference 8: Characterization of the Nanoscale in Triacylglycerol Crystal Networks Formulation of RBW oleogels Oleogel research landscape at UoN

Characterisation

Functionalisation

Application: cakes & SCP (LMWO) Oleogels: Definition

•Organic liquid entrapped within a thermo- reversible, three-dimensional gel network3

•Network: Thermo-reversible 3D supramolecular structure formed via self-assembly of small molecules in an organic solvent at low concentration4. RBW Oleogels: preparation

Formulation definition

Solubilisation

Crystallisation

Structure Development RBW oleogels: Appearance

RBW concentration (%)

0.0% 0.1% 0.2% 0.5% 1.0% 2.0% 3.0% 5.0% RBW oleogels: microstructure RBW oleogels: microstructure Oleogel research landscape at UoN

Characterisation

Functionalisation

Application: cakes & SCP Microstructure functionalisation: Understanding the thermo-mechanical behaviour

Formulation [RBW] Processing Additives Cooling Thermodynamic/kinetics rate Temperature Shear 100 µm Microstructure = f([RBW])

1.0% 1.5% 2.0%

2.5% 3.0% 5.0% RBW oleogels thermal properties

Liquid oil 3.0 Oleogel 2.5 /g) 2.0 mW 1.5

1.0 Heat Flux ( Heat 0.5

0.0 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 Temperature (°C) Gel strength = f(Temperature)

100,000 2% RBW ω = 10 rad/s 10,000

1,000 G' (20C) G'' (20C)

100 G' (30C) G'' (30C) G', G'' (Pa) G' (40C) G'' (40C)

10 G' (50C) G'' (50C)

G' (55C) G'' (55C) 1 0.001 0.01 0.1 1 10 100 1000 γ (%) Engineering the mechanical behaviour= f([RBW], cooling rate)

0.5 °C/min 50 °C/min 240

200

160

120

80 3% RBW Yield Stress (Pa) Stress Yield

40 200 µm 5% RBW 200 µm

0 0.1 1 10 100 Cooling rate (°C/min)

PP50 Sandblasted, ω = 10 rad/s, 40 °C, 0.5 mm gap Engineering the mechanical behaviour= f([RBW], cooling rate)

80% 80% 70% 0.5°C/min 70% 5°C/min 60% 60%

50% 50%

40% 40%

30% 30% % of crystals

20% % of crystals 20%

10% 10%

0% 0% 50 100 150 200 250 >250 50 100 150 >150 Lenght of crystals - classes (µm) Length of crystals - classes (µm)

60%

50% 50°C/min Average number (%) of 40% crystals in each 30% length class

after cooling, at % of crystals 20% 27°C (1%RBW) 10%

0% 25 50 >50 Length of crystals - classes (µm) Role of additives on RBW oleogels Control (0% Emulsifier)

200 µm 1% Span 60 1% Span 65 Crystallisation profile of RBW + Additive (Span 65)

1% Sp65/1% RBW

Heat flow 0.2 (mW) 0.2 flow Heat 0.5% Sp65/1% RBW 0.1% Sp65/1% RBW 1% RBW 20 30 40 50 60 70 80 90 Temperature (°C) Application Pastry re-formulation

Palm oil 20% Replacement with 3% RBW

Images taken by Khatija Nawaz Husain (CIM Nottingham) 4. Key features of wax oleogels research

Reversible physical Increased modification PUFA of oils

Type, origin & recovery Matching strategy fats functionality

Health Sustainability Natural Economical value / by- Functionality Delayed products lipolysis valorisation RBW for oleogelation: Key features

• Low molecular weight gelators

• Unidirectional molecular packing leading to anisotropic platelet shaped crystals with β’ sub-cell structure

• Long range intermolecular interactions

• Self-arrange to form a dispersion of crystals sintered to form an oil-structuring continuous network

• The addition of additives promotes new microstructural arrangement mirrored by different crystallisation profile Many thanks for your attention

Any Questions?