Emulsion technology, a review.


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Emulsion technology, a review.

  2. 2. Introduction • With rapidly growing global population resulting in an ever- increasing demand for food and new energy resources, there is a significant demand for food, agriculture and biosystems research to deliver food, drink, and biomaterials with low cost, low environmental impact systems (Technology Review 2001) • Agricultural and Biosystems researchers around the world are focusing on every aspect of food chain from the farm to the fork by adopting state-of-the-art technologies to turn raw materials into food and biomaterials 2
  3. 3. • To answer the complex set of engineering and scientific challenges in the agri-food industry, innovation is needed for new processes, products and tools 3
  5. 5. What is emulsion • An emulsion is a colloidal system containing droplets of one liquid dispersed in another, the two liquids being immiscible. The droplets are termed the dispersed phase, and the liquid that contains them is termed the continuous phase • In food emulsions, the two liquids are oil and water 5
  6. 6. • An emulsion also must contain an emulsifier, which coats the emulsion droplets and prevents them from coalescing or recombining with each other • They are immiscible in aqueous solutions and more soluble in liquid media, including the cell membrane(Obraztosov et al., 2000) 6
  7. 7. Oil-in-water and water-in-oil food emulsion such as mayonnaise and margarine respectively can be industrially produced by introducing energy through physical means in a mixer equipment leading to shearing strains which will break up to form one phase into the other.(Skurtys et al., 2008, Zwan et al., 2006) 7
  8. 8. A REVIEW • Microfluidics is one of the top 10 emerging technologies that will change the world market by having a profound impact on the economy and how we live and work (Technology Review 2001) • Microfluidics is generally defined as the science and technology of systems that process or manipulate small (10- 18) litres of fluids, using channels with dimensions of a few to hundreds of micrometers (Whitesides 2006) 8
  9. 9. The technology • Microfluidic device have potential to dispense chemicals in a controlled manner at the scale of droplets to tailor the properties of emulsion(Zwan et al., 2006) • Microfludic technology has already been applied for detection of mastitis in the animal prediction systems.(Choi et al., 2006) 9
  10. 10. Forming an emulsion • To form an emulsion, two liquids that do not normally mix must be forced to do so. To understand how this is achieved, we must first consider the forces between the molecules of a liquid • The water molecules are attracted to one another other by hydrogen bonds 10
  11. 11. Emulsion Formation • An emulsion is formed when oil, water, and an emulsifier are mixed together. Although there are different food emulsions, they all contain these three components • To form an emulsion, it is necessary to break up either the oil or the water phase into small droplets that remain dispersed throughout the other liquid. This requires energy and usually is carried out using a mixer or a homogenizer 11
  12. 12. Principles of Formation of a Stable Oil-In-Water Emulsion • Emulsifier is dispersed in the aqueous phase. • Oil is added and the interfacial tension of each liquid is reduced by the emulsifier • Energy is supplied by beating or homogenizing the mixture • The oil phase is broken up into droplets, surrounded by water • Emulsifier adsorbs at the freshly created oil droplet surfaces • Small droplets are formed, protected by an interfacial layer of emulsifier 12
  13. 13. • The interfacial area of the oil becomes very large • The aqueous phase spreads to surround each oil droplet • The emulsion may become thick due to many small oil droplets surrounded by a thin continuous phase • If the interfacial film is strong, the emulsion will be stable 13
  14. 14. Emulsifiers must be able to • Adsorb at the interface between two liquids such as oil and water • Reduce the interfacial tension of each liquid, enabling one liquid to spread more easily around the other • Form a stable, coherent, viscoelastic interfacial film • Prevent or delay coalescence of the emulsion droplets 14
  15. 15. Natural Emulsifiers • The best emulsifiers are proteins, which uncoil or denature and adsorb at the interface and interact to form a stable interfacial film • The proteins of egg yolk tend to be the best emulsifiers, as exemplified by their use in mayonnaise • The caseins of milk are also excellent emulsifying agents 15
  16. 16. Synthetic Emulsifiers or Surfactants • Most synthetic emulsifiers would more correctly be termed surfactants, because they are relatively small molecules compared with proteins, and they are used mainly to aid in dispersion of fat rather than to stabilize emulsions. Surfactants such as mono- and diglycerides are added to shortening and to cake mixes to aid in dispersion of the shortening 16
  17. 17. Examples of Emulsions • French dressing is an example of a temporary emulsion, or in other words, an unstable emulsion that separates fairly soon after formation • The “emulsifiers” used here are the mustard and paprika. Combining the ingredients and shaking them vigorously forms the emulsion 17
  18. 18. What is meat emulsion In a meat emulsion, fine fat droplets are dispersed in an aqueous medium containing • soluble proteins, other soluble muscle constituents, segments of muscle fibers and connective tissue fibers • In a stable emulsion, each fat droplet is coated with a thin layer of soluble protein which has been released into the aqueous medium from the muscle fibers 18
  19. 19. Fig 1. Emulsified meat. Copyright © 2001 E. I. du Pont de Nemours and Company All rights reserved 19
  20. 20. Emulsified Meat Manufacture • There are two primary methods of manufacture. Both have advantages and disadvantages – Mixer Emulsifier (continuous system) – Bowl Chopper (batch system) • A bowl chopper is more efficient for extracting lean meat proteins. • A mixer emulsifier system is capable of higher through put. 20
  21. 21. Fig 2. Grinding - Meat Preparation Copyright © 2001 E. I. du Pont de Nemours and Company All rights reserved. 21
  22. 22. Fig 3. Mixing Copyright © 2001 E. I. du Pont de Nemours and Company All rights reserved. 22
  23. 23. Fig 4. Emulsified Meat Manufacture Copyright © 2001 E. I. du Pont de Nemours and Company All rights reserved. 23
  24. 24. Fig 5. Filling/Stuffing Copyright © 2001 E. I. du Pont de Nemours and Company All rights reserved. 24
  25. 25. Conclusion • Emulsion technology has help in improving and maintaining agric-product shelf life and understanding their formation and stability is important if the quality and shelf life of products are to be maintained and improved 25
  26. 26. References Charley H, Weaver C. Foods: A Scientific Approach, 3rd ed. Upper Saddle River, NJ: Prentice-Hall, 1998. Choi, J., Y. Kim., H. Kim., W. Lee, and H.S. Gi. 2006. Lab- on- a-chip for monitoring the quality of raw milk. J. Microbiol. Biotechnol. 16: 1229-1235 Devendra Kumar* and V. K. Tanwar (2010).Utilization of clove powder as Phytopreservative for chicken nuggets preparation. Dimov, I.K., J.L. Garcia-Cordero, J. O’Grady, C.R. Poulsen, C. Viguier, L. Kent, P. Daly, B. Lincoln, M. Maher, R. O’Kennedy, T.J. Smith, A.J. Ricco, and L.P. Lee. 2008. Integrated microfluidic tmRNA purification and real-time NASBA device for molecular diagnostics. Lab Chip 8: 26
  27. 27. McWilliams M. Foods: Experimental Perspectives, 4th ed. Upper Saddle River, NJ: Prentice-Hall, 2001 Obraztsov VV, Neslund GG, Kornbrust ES, Flaim SF, Woods CM. In vitor cellular effects perfluorochemicals correlate with their cellular lipid solubility. Am J Physiol Lung Cell Mol Physiol 2000; 278: L1018-24. Skurtys, O, and J.M. Aguilera. 2008. Applications of microfluidic devices in food engineering. Food Biophys. 3(1): 1-15 Technology Review. 2001. Emerging technologies that will change the world. Massachusetts Institute of Technology. 27
  28. 28. Walstra P. Dispersed systems—Basic considerations. In: Fennema O, ed. Food Chemistry, 3rd ed. New York: Marcel Decker, 1996. Whitesides, G.M. 2006. The origins and the future of microfluidics. Nature 442(27): 368-373. Zwan, E.V., K. Schroen, K.V. Dijke, and R.M. Boom. 2006. Visualization of droplet break-up in pre-mix membrane emulsification using microfluidic devices. Colloid Surface 277: 223-22.9 28
  29. 29. Thanks for listening…….. 29