Investigation of diffusion ouf of different fat matrices – especially for iron in palm fat Supervisor: Christina Käppeli Co-Referee: Dr. Hanselmann Referee: Prof. Windhab Master Thesis Presentation of Vincent Keehnen

 Introduction  Objectives  Methods  Results  Discussion  Summary  Outlook Thursday, November 24th, 20112D-AGRL, IFNH, Laboratory of Food Process Engineering PRESENTATION STRUCTURE

Thursday, November 24th, 20113D-AGRL, IFNH, Laboratory of Food Process Engineering INTRODUCTION  Damages physical performance, cognitive abilities, immune system  severe impact on individual health and national productivity 2  One strategy to combat iron deficiency: Iron supplementation  iron pills or injections containing iron  Many iron supplementation treatments rely on diffusion  iron pills: Fat matrix releases iron into the stomach  Palm fat fraction with a high melting point of around 61 ° C  palm fat matrices suitable for tropical climates!  Iron deficiency affects 2 billion people worldwide  especially severe in Third World Countries 1

Thursday, November 24th, 20114D-AGRL, IFNH, Laboratory of Food Process Engineering INTRODUCTION Diffusion  Definition: 3  mass transfer process  caused by concentration gradient  Mathematics:  Fick’s second law: concentration changes with time and position  carried out by Brownian motion  Fick’s first law: matter flows towards lower concentration  results in gradual mixing of material Diffusion coefficient D Diffusion coefficient D: 3 Mobility of an agent migrating through a certain medium [m 2 /s]

Thursday, November 24th, 20115D-AGRL, IFNH, Laboratory of Food Process Engineering INTRODUCTION  Frame: PhD Project aiming at developing different fat capsules loaded with iron in collaboration with Human Nutrition Group  remain up to 24 hours in the human stomach  slowly release iron in a controlled fashion  Central: Controlled release!  too fast: non-transferrin bound iron  infections 2  too slow: capsule leaves stomach  less iron released  Challenges:  how to achieve controlled and full release during 24 hours?  how to ensure reproducibility? = to set a particular agent free with a defined amount, at a certain time and at specific location 4

Thursday, November 24th, 20116D-AGRL, IFNH, Laboratory of Food Process Engineering OBJECTIVES  Develop a reproducible method to measure the diffusion coefficient D of iron out of palm fat  Optimize the controlled release of iron out of palm fat to achieve 80 to 100 % release after 24 hours in vitro Demonstrate the technical feasibility of the project in vitro!

Thursday, November 24th, 20117D-AGRL, IFNH, Laboratory of Food Process Engineering METHODS  Idea: Place palmfat-based films loaded with iron in an acidious solution to simulate the release behavior of fat capsules in the human stomach Preparation of palmfat-based films homogeneously loaded with a specified amount of iron sulfate (~ Quinbin, 2006) Carry out unsteady-state diffusivity measurements with these films to obtain the diffusion coefficient D simulating stomach conditions

Thursday, November 24th, 20118D-AGRL, IFNH, Laboratory of Food Process Engineering METHODS  Calculation of the Diffusion Coefficient D: 5 y slope [s -1 ] intercept t = independent variable (x) [s] D [m 2 /s]

Thursday, November 24th, 20119D-AGRL, IFNH, Laboratory of Food Process Engineering RESULTS  Fractures and cracks  Inhomogeneous crystallization Preparation of palmfat-based films Problems and Solutions  faster pouring and homogeneous surrounding temperatures  Air bubbles  Inhomogeneous distribution of iron  slow and careful flat-rolling of the cover sheet  replace manual stirring with high intensity automated stirring  homogeneous cooling temperatures

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering RESULTS  Down-Bending Unsteady state diffusivity measurement Problems and Solutions  cage stir bar in plastic device to prevent spout formation (partial solution due to density difference)  Up-bending  Increase volume of HCl-solution to ensure coverage in spite of up-bending

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering RESULTS Conditions: 37 ˚C, 0.1 M HCl, 800 mL

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering DISCUSSION Objective: Reproducibility?  Achieved by homogeneously processing the films  similar treatment due to automated stirring  homogeneous distribution of iron by high intensity stirring  avoidance of damage and irregularities  reduction of pouring volume

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering DISCUSSION Objective: Reproducibility?  Comparison: After: Before:

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering DISCUSSION Objective: Controlled and full release?  Almost completely achieved by increasing iron sulfate content to 17.2 % [w/w] reaching 90 % within 24 hours  Reduced stirring: reduced release probably due to less homogeneous mixing of the iron within the solution  Reduction in particle size: reduced release probably due to smaller particles more easily trapped in fat crystal matrix (analogous to chromatography)  Increase in FeSO 4 -Content: increased release probably due to stronger concentration gradient

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering DISCUSSION Outlook  Surfactants and emulsion-matrices?  Influence of different microstructures and additives?  Fat-mixtures and different fat matrices?  Other possibilities to influence and change release?  Possibilities for application:  Flavor release technology  Functional foods products  Fight against other micronutrient deficiencies  Optimum settings for maximum release?

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering CONCLUSION AND SUMMARY  Method with high reproducibility developed  Controlled release of iron out of palm fat achieved  Technical feasibility of the project demonstrated

Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering REFERENCES 1 Hurrell et al.: Particle size reduction and encapsulation affect the bioavailability of ferric pyrophosphate in rats, Journal of Nutrition, WHO: Iron deficiency anemia: Assessment, prevention, and control, Geneva, Cussler: Diffusion: Mass transfer in fluid systems, Pothakamury and Barbosa-Cánovas: Fundamental aspects of controlled release in foods, Trends in Food Science & Technology, Han: Mass transfer modelling in closed systems for food packaging, particulate foods and controlled release technology, Food Science and Biotechnology, 2004

Thank you for your attention Thursday, November 24th, D-AGRL, IFNH, Laboratory of Food Process Engineering