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Competitive Displacement of Methylcellulose from Oil-Water Interface by Various Emulsifiers

저분자량 유화제 첨가에 의한 계면 흡착 메칠셀룰로오스의 경쟁이탈 특성 연구

  • 홍순택 (호원대학교 식품외식조리학부)
  • Published : 2008.10.31

Abstract

Competitive displacement of methylcellulose (MC) absorbed at the oil-water interface was investigated by interfacial composition, surface shear viscosity, or surface tension measurements. It was found that all emulsifiers could competitively displace the interfacial MC from the oil-water interface but their behaviors were different from each other. With Tween 20 added to MC emulsion (1 wt% MC, 10 wt% n-tetradecane, 20 mM bis-tris, pH 7), MC load was steadily decreased with increasing concentrations of the emulsifier, as confirmed by surface shear viscosity measurements; moreover, there was complete MC displacement from the emulsion droplet surface at high concentration (0.1 wt%). The oil-soluble Span 80 was found to show a synergism with MC at the interface, which resulted in higher MC load at relatively low emulsifier concentrations ($\leq$0.05 wt%). At a higher emulsifier concentration (0.1 wt%) limited MC displacement was observed. These results were well supported by surface shear viscosity measurements. With water-soluble SDS, MC load was decreased with increasing concentrations of the emulsifier. Unlike Tween 20, however, it was found that at high concentrations (> 0.1 wt%), there was still some MC remaining at the droplet surface. Surface tension measurements are suggestive of an interfacial complex between MC and SDS.

본 연구는 MC를 함유하는 유화식품 제조에 필요한 기초 자료를 얻고자 물/기름 계면에서 저분자량 유화제와 계면 흡착 MC와의 경쟁이탈(혹은 흡착) 현상을 구명하고자 수행 하였다. 경쟁이탈 특성 변화는 계면막 조성 분석, 표면 전단 점도 측정 혹은 표면 장력을 측정하여 분석하였다. MC 유화액(1 wt% MC, 10 wt% n-tetradecane, 20 mM bis-tris, pH7)에 수용성 Tween 20을 첨가할 경우 첨가 농도의 증가에 따라 MC 흡착량이 감소하여 0.1 wt% 첨가 농도에서 모든 계면에 흡착된 MC가 수용액으로 이탈되었으며, 표면 전단 점도를 측정 결과도 이와 잘 일치하였다. 지용성 Span 80을 첨가할 경우 낮은 농도에서($\leq$0.05 wt%) 유화제를 첨가하지 않은 경우와 비교하여 MC load가 약 10$\sim$25% 증가하였고 (상승작용), 농도의 증가와 더불어 흡착량은 감소하였으나 고농도(0.1 wt%)에서 MC 분자의 완전한 경쟁 이탈은 관찰되지 않았다. 또한, 표면 전단 점도 측정을 통하여 물/기름 계면에서 MC와 Span 80 간의 상승작용을 확인할 수 있었다. 수용성 SDS 첨가할 경우 경쟁 이탈 현상은 Tween 20의 경우와 비교하여 다소 다른 형태를 나타내었다. 즉 SDS 첨가 농도의 증가와 더불어 MC load는 점차로 감소하는 경향을 보였으나 Tween 20 첨가의 경우와 달리 높은 SDS농도(> 0.1 wt%)에서도 유화 지방구 표면에는 약간의 MC가 존재하고 있는 것으로 분석되었고, 이를 SDS와 MC 분자간의 경쟁 이탈 현상 혹은 복합체 형성을 시사하는 것으로 추정하였으며, air-water 표면 장력의 변화도 이와 잘 일치하고 있었다. 결론적으로 계면에 흡착된 MC는 저분자량 유화제에 의하여 수용액 상으로 경쟁이탈(competitive displacement) 되었으며, 그 형태는 유화제 종류에 따라 다르게 나타난 것으로 관찰되었다.

Keywords

References

  1. Dickinson E. 1992. An Introduction to Food Colloids. Oxford University Press, Oxford. p 1-29
  2. Williams PA, Phillips GO. 2000. Introduction to food hydrocolloids. In Handbook of hydrocolloids. Williams PA, Phillips GO, eds. Woodhead Publishing Limited, Cambridge. p 1-20
  3. Zecher D, Gerrish T. 1997. Cellulose derivatives. In Thickening and Gelling Agents for Food. Imeson A, ed. Blackie Academic & Professional, London. p 60-87
  4. Hong ST. 2008. Influence of methylcellulose on properties of $\beta$-lactoglobulin emulsions. Food Engin Prog 12: 121-127
  5. Sarkar N. 1984. Structural interpretation of the interafacial properties of aqueous solutions of methylcellulose and hydroxypropyl methylcellulose. Polym 25: 481-486 https://doi.org/10.1016/0032-3861(84)90206-4
  6. Wollenweber C, Makievski AV, Miller R, Daniels R. 2001. Adsorption of hydroxypropyl methylcellulose at the liquid/liquid interface and the effect on emulsion stability. Colloid Surf A 172: 91-101 https://doi.org/10.1016/S0927-7757(00)00569-0
  7. Sarker DK, Axelos M, Popineau Y. 1999. Methylcelluloseinduced stability changes in protein-based emulsions. Colloids Surf B 12: 147-160 https://doi.org/10.1016/S0927-7765(98)00071-X
  8. Gullapalli RP, Sheth B. 1996. Effect of methylcellulose on the stability of oil-in-water emusions. Int J Pharm 140: 97-109 https://doi.org/10.1016/0378-5173(96)04591-7
  9. Hong ST. 1996. Influence of surfactants on properties of $\beta$-lactoglobulin emulsions and heat-treated emulsion gels. PhD Dissertation. University of Leeds, Leeds
  10. Dickinson E, Rolfe SE, Dalgleish DG. 1990. Surface shear viscosity as a probe of protein-protein interactions in mixed protein films adsorbed at the oil-water interface. Int J Biol Macromol 12: 189-194 https://doi.org/10.1016/0141-8130(90)90031-5
  11. Dickinson E, Murray BS, Stainsby G. 1985. Time-dependent surface viscosity of adsorbed films of casein+gelatin at the oil-water interface. J Colloid Interface Sci 106: 259-262 https://doi.org/10.1016/0021-9797(85)90406-0
  12. McClements DJ. 2004. Food Emulsions: principles, practices, and techniques. 2nd ed. CRC Press, Boca Raton, Florida. p 175-232, 461-514
  13. Kanzaki G, Berger EY. 1959. Colorimetric determination of methylcellulose with diphenylamine. Anal Chem 31: 1385-138531 https://doi.org/10.1021/ac60152a043
  14. Dickinson E, Mauffret A, Rolfe SE, Woskett CM. 1989. Adsorption at interfaces in dairy systems. J Soc Dairy Technol 42: 18-22 https://doi.org/10.1111/j.1471-0307.1989.tb01702.x
  15. Gramham DE, Phillips MC. 1979. Proteins at liquid interfaces. III. Molecular structures of adsorbed films. J Colloid Interface Sci 70: 427-439 https://doi.org/10.1016/0021-9797(79)90050-X
  16. Methocel Cellulose Ethers Technical Handbook. 1996. Dow Chemical Co. Form No. 192-01062-1296XGW
  17. Dickinson E, Woskett CM. 1989. Competitive adsorption between proteins and small-molecule surfactants in food emulsions. In Food Colloids. Bee RD, Richmond P, Mingins J, eds. Royal Society of Chemistry, Cambridge. p 74-96
  18. Darling DF, Birkett RJ. 1987. Food colloids in practice. In Food Emulsions and Foams. Dickinson E, ed. Royal Society of Chemistry, London. p 1-29
  19. Courthaudon JL, Dickinson E, Dalgleish DG. 1991. Competitive adsorption of $\beta$-casein and nonionic surfactants in oil-water emulsions. J Colloid Interface Sci 145: 390-395 https://doi.org/10.1016/0021-9797(91)90369-J
  20. Dickinson E, Owusu RK, Tan S, Williams A. 1993. Oil-soluble surfactants have little effect on competitive adsorption of $\alpha-lactalbumin and \beta$-lactogloulin in emulsions. J Food Sci 58: 295-298 https://doi.org/10.1111/j.1365-2621.1993.tb04259.x
  21. De Feijter JA, Benjamins J, Tamboer M. 1987. Adsorption displacement of proteins by surfactants in oil-in-water emulsions. Colloid Surf 27: 243-266 https://doi.org/10.1016/0166-6622(87)80340-2
  22. Dickinson E. 1991. Competitive adsorption and proteinsurfactant interactions in oil-in-water emulsion. ACS Symp Ser 448: 114-129 https://doi.org/10.1021/bk-1991-0448.ch009
  23. Arboley JC, Wilde PJ. 2005. Competitive adsorption of proteins with methylcellulose and hydroxypropyl methylcellulose. Food Hydrocoll 19: 485-491 https://doi.org/10.1016/j.foodhyd.2004.10.013
  24. Djuve J, Pugh RJ, Sjoblom J. 2001. Foaming and dynamic surface tension of aqueous polymer/surfactant solutions 1: ethyl(hydroxyethyl) cellulose and sodium dodecyl sulphate. Colloid Surf A 186: 189-202 https://doi.org/10.1016/S0927-7757(00)00787-1
  25. Nystrom B, Walderhaug H, Hansen FK. 1995. Rheological behavior during thermoreversible gelation of aqueous mixtures of ethyl(hydroxyethyl) cellulose and surfactants. Langmuir 11: 750-757 https://doi.org/10.1021/la00003a014

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