Journal of the Korean Society of Food Science and Nutrition (한국식품영양과학회지)

The Korean Society of Food Science and Nutrition (한국식품영양과학회)
권호 표지

Total Free SH Groups, Half Cystine and S-S Bond Contents of $\alpha$-Lactalbumin Gels by Various Additives

첨가물질에 따른 알파-락트알부민 겔의 총 유리 SH 그룹, Half-Cystine 및 S-S 결합 함량

  • 박인덕 (전남대학교 식품영양학과) ;
  • 홍윤호 (전남대학교 식품영양학과)
  • Published : 1996.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

In order to investigate heat-induced gelation properties of $\alpha-lactalbumin(\alpha-La),$ total free SH groups, half-cystine, and disulfide bond contents of $\alpha-La$ gels prepared in 0.1M Tris-HCI buffer(pH 8.0) were measured. The samples were heated at $90^{\circ}C$ for 40 minutes under different PH and concentrations of NaCl, $CaCl_2,$ $\alpha-La,$ N-ethylrnaleirnide(NEM), and dithiothreitol(DTT). Total free SH groups were low at high concentrations of $\alpha-La$ and at pH 6.5~8.5, and were $14.72~18.58\mu\textrm{m}ol/g$ and $14.17~16.11\mu\textrm{m}ol/g,$ respectively. Half-cystine contents of NEM-induced gels decreased with increasing concentration of NEM, and were $1.03~39.17\mu\textrm{m}ol/g.$ Disulfide bonds of DTT-induced gels increased with increasing concentration of DTT, and were $70.04~71.80\mu\textrm{m}ol/g$.

본 연구에서는 열처리에 의한 $알파-락트알부민(\alpha-La)겔의$ 특성을 규명하기 위하여 겔형성에 관여하는 인자들 즉, 염의 종류와 농도, pH, $\alpha-La$ 농도, 티올시약(NEM, Dn)의 농도를 각각 변화시켜 $90^{\circ}C에서$ 40분간 가열하여 만든 알파-락트알부민 겔의 총유리 SH그룹, half-cystine 함량, S-S 결합 함량을 측정하였다. 총 유리 SH 그룹, half-cystine 함량, S-S 결합은 첨가된 염의 종류와 농도 변화에는 큰 의존성을 나타내지 않았다. pH 2.5~3.5에서는 SH 그룹의 반응성이 낮아 pH 6.5~8.5에서의 총 유리 SH 그룹 보다 함량이 더 높고 half-cystine 함량은 일정하였으나 형성된 S-S 결합은 더 낮아 pH가 증가할수록 SH산화속도와 겔망상 구조의 형성 이 가속화됨을 확인할 수 있었다. $\alpha-La의$ 농도 증가로 half-cystine 함량은 큰 변화가 없었으나 총 유리 SH 그룹은 약간 감소하고 S-S 결합은 약간 증가하여 $\alpha-La의$ 농도 증가에 따라 겔지지체에서 S-S 결합의 관여가 큼을 나타내었다. NEM첨가의 경우는 총 유리 SH그룹과 half-cystine 함량이 급격히 감소하였으나 S-S 결합은 증가하여 NEM 첨가로 SH그룹이 반응성을 잃어 결국 $\alpha-La의$ 겔형성에 지장을 줌을 확인하였다. DTT 첨가로는 새로운 분자간 티올-이황화물 상호교환반응이 용이하게 되어 총 유리 SH 그룹은 낮고 S-S 결합은 높은 함량을 나타내었다.

Keywords

References

  1. Korean J. Nutr. Society v.16 Nutritional properties and utilization of bovine whey Hong, Y. H.
  2. IDF Bulletin v.212 Fractionation and modification of whey protein in U.S. Morr, C. V.
  3. In developments in dairy chemistry-4. The use of whey protein products De Wit, J. N.
  4. J. Food Sci. v.54 Molecular properties and functionality of proteins in food gels Foegeding, E. A.
  5. Trends in Food Sci. & Tech. v.1 Functional characteristics of dairy proteins Rost, J.
  6. Neth. Milk Dairy J. v.38 Functional properties of whey proteins in food systems De Wit, J. N.
  7. J. Food Sci. v.55 Viscoelastic properties of whey protein gels Katsuta, K.;Rector, D.;Kinsella, J. E.
  8. A status report. Food Technol. v.44 Composition and functionality of commercial whey and milk protein concentrates and isolates Morr, C. V.;Foegeding, E. A.
  9. J. Food Sci. v.57 Gelation of commercial whey protein concentrates : Effect of removal of low molecular weight components Brandenberg, A. H.;Morr, C. V.;Weller, C. L.
  10. J. Food Sci. v.57 Gelation and emulsification properties of partially insolubilized whey protein concentrates Beuschel, B. C.;Culbertson, J. D.;Patridge, J. A.;Smith, D. M.
  11. J. Dairy Sci. v.65 Thermal denaturation and gelation of whey proteins and their adsorption at the air/water interface Paulsson, M.
  12. Food Technol. v.41 Gelation characteristics of whey proteins and β-latoglobulin Mulvihill, D. M.;Kinsella, J. E.
  13. J. Agric. Food Chem. v.40 Influence of pH and ionic environment on thermal aggregation of whey proteins Xiong, Y. L.
  14. Neth. Milk Dairy J. v.46 Protein solubility and gelation behavior of whey protein concentrates prepared by ultra-filtration of sweet cheese whey Gupta, V. K.;Reuter, H.
  15. Biochimica et Biophysica Acta v.624 Hydrophobicity determined by a fluorescence probe method and its correlation with surface properties of proteins Kato, A.;Nakai, S.
  16. Food Chem. v.40 Gelation of bovine serum albumin and β-lactoglobulin : Effects of pH, salts, and thiol reagents Matsudomi, N.;Rector, D.;Kinsella, J. E.
  17. J. Agric. Food Chem. v.41 Interations of α-La and BSA with β-Lg in thermally induced gelation Hienes, M. E.;Foegeding , E. A.
  18. Food Res. Int. v.26 Heat-induced gelation of the mixtures of α-La and β-Lg in the presence of glutathione Legowu, A. M.;Imada, T.;Hayakaya, S.
  19. Food Research Int. v.26 Heat-induced gelation of the mixtures of α-lactabumin and β-latoglobulin in the presence of glutathione Legowu, A. M.;Imada, T.;Hayakawa, S.
  20. J. Dairy Res. v.37 The denaturation of α-lactalbumin and β-lactoglobulin in heated milk Lyster, R.
  21. J. Agric. Food Chem. v.39 Raman spectroscopic study of thermally and/or dithiothreitol induced gelation of lysozyme Li-chan, E.;Nakai, S.
  22. J. Agric. Food Chem. v.36 Texture characteristics, protein solubility, and sulfhydryl group/disulfide bond contents of heat-induced gels of whey protein Shimada, K.;Cheftel, J. C.
  23. J. Agric. Food Chem. v.36 Determination of sulfhydryl groups and disulfide bonds in heat-induced gels of soy protein isolate Shimada, K.;Cheftel, J. C.
  24. J. Agric. Food Chem. v.41 Enhancing the gelation of β-Lg Lee, S. P.;Cho, Y.;Batt, C. A.
  25. J. Dairy Res. v.61 Thermal gelation and denaturation of bovine β-lactoglobulins A and B McSwiney, M.;Singh, H.;Campanella, O.;Creamer, L. K.
  26. Arch. Biochem. Biophys. v.82 Tissue sulfhydryl groups Ellman, G. C.
  27. Int. Dairy J. v.5 Factors affecting molecular characteristics of whey protein isolates Boye, J. I.;Alli, I.;Ismail, A. A.;Gibbs, B. F.;Kinishi, Y.
  28. J. Dairy Sci. v.76 Thermal aggregation of β-lactoglobulin : Effect of pH, ionic environment, and thiol reagent Xiong, Y. L.;Dawson, K. A.;Wan, L.
  29. In advanced dairy chemistry v.1 Heat stability of milk Fox, P. F.
  30. Agric. Biol. Chem. v.48 Effect of heating temperature on sulfhydryl and disulfide contentsand state of aromatic amino acid residues in soybean protein Yamagishi, T.;Takaya, M.;Ebina, F.;Yamaguchi, F.
  31. J. Agric. Food Chem. v.37 Effect of disulfide bond cleavage on structural and interfacial properties of whey proteins Kella, N. K. D.;Yang, S. T.;Kinsella, J. E.
  32. J. Food Sci. v.54 Physicochemical parameters of proteins by additives and their emulsifying properties Toro-Vazquez, J. F.;Regenstein, J. M.