The Effect of Emulsifying Salts on Physicochemical Properties and Enzymatic Gelation Time of Skim Milk

Subject Areas : Microbiology

Mahdokht Ehteshami ¹ (دانشجوی کارشناسی ارشد دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران، ایران)
Hamid Ezzatpanah ² (دانشیار گروه تخصصی علوم و صنایع غذایی، دانشکده کشاورزی و منابع طبیعی، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران، ایران)
Soleyman Abbasi ³ (دانشیار آزمایشگاه کلوئیدهای غذایی و رئولوژی، دانشگاه تربیت مدرس، دانشکده کشاورزی، گروه علوم و صنایع غذایی، تهران، ایران)
Mohammad Hadi Givianrad ⁴ (استادیار دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران، گروه شیمی تجزیه، ایران)

Received: 2012-12-10 Accepted : 2013-05-11 Published : 2013-09-23

Keywords: Enzyme Induced Casein Gel, Gelation Time, Tetrasodium Pyrophosphate, Trisodium Citrate,

Abstract :

Introduction: Milk proteins are able to form gel under different situations such as heating, acidification, adding the enzymes and emulsifying salts. In this study, the effect of adding tetrasodium pyrophosphate (TSPP) and trisodium citrate (TSC) on physicochemical properties and rennet gelation time of unheated and heated skim milk was investigated. Materials and Methods: 2 to 10 mM TSPP and TSC were added to unheated and heated reconstituted skim milk. The pH, electro-conductivity (EC), and turbidity of samples were measured and upon the rennet treatment, the gelation time and water holding capacity (WHC) of treated samples were determined.Results: Based on our findings, addition of TSPP and TSC increased the pH and EC while it decreased the turbidity of the samples. Moreover, the presence of these salts extended the rennet gelation time of induced casein gels and gelation was only observed in the samples containing 2 and 4 mM TSC, and 4, 6, and 8 mM TSPP. The WHC of the samples was increased as well.Conclusion: TSPP and TSC resulted in dispersing the casein and forming a new gel networks, that can contribute to the improvement of some properties of milk products.

References:

Anema, S. H., Lee, S. K. & Klostermeyer, H. )2007(. Effect of pH at heat treatment on the hydrolysis of к-casein and the gelation of skim milk by chymosin. LWT, 40: 99-106.

Auty, M. A. E., O’Kenedy, B. T., Allen-Woijtas, P. & Mulvihill, D. M. )2005(. The application of microscopy and rheology to study the effect of milk salt concentration on the structure of acidified micellar casein systems. Food Hydrocolloids,19: 101-109.

Dalgleish, D. G. )1979(. Proteolysis and aggregation of casein miselles treated with immobilized or soluble chymosin. J. Dairy Res, 46: 653-661.

Fox, P. F., Guinee, T. P., Cogan, T. M. & McSweeney, P. L. H. )2000(. Fundamentals of Cheese Science. Aspen Publishers Inc., Gaithersburg, MD.

Fox, P. F., McSweeney, P. L. H., Cogan, T. M. C. & Guinee, T. P. )2004(. Cheese: Chemistry, Physics and Microbiology. Elsevier Ltd.

Hui, Y. H. )1993(. Dairy Science and Technology Handbook. Wiley-VCH, Inc.

Lucey, J. A. & Horne, D. S. )2009(. Milk Salts: Technological Significance in P. F. Fox and P. L. H. Mcsweeney (ed). Advanced Dairy Chemistry. vol. 3: Lactose, Water, Salts and Minor constituents. Springer Science and Business Media , LLc.

 

Li, J. & Dalgleish, D. G. )2006(. Controlled proteolysis and the propertoes of milk gels. Journal of Agriculture and Food Chemistry, 54: 4687-4695.

Marshall, R. J. )1986(. Increasing cheese yields by high treatment milk. Journal of Dairy Research, 53: 513-522.

Mizuno, R. & Lucey, J. A. )2005(. Effects of Emulsifying Salts on the Turbidity and Calcium-Phosphate-Protein Interactions in Casein Micelles. J. Dairy Sci, 88:3070-3078.

Mizuno, R. & Lucey, J. A. )2007(. Properties of Milk Protein Gels Formed by Phosphates. J. Dairy Sci, 90: 4524-4531.

Morr. C. V. )1967(. Some Effects of pyrophosphate and citrate ions upon the colloidal caseinate-phosphate micelles and ultrafiltrate of raw and heated skim milk. Journal of Dairy science, 50: 1038-1044.

Munyua, J. K. & Larsson-Raznikiewicz, M. )1980(. The influence of Ca2+ on the size and light scattering properties of caSsein micelles. 1. Ca2+ removal. Milchwissenschaft, 55: 604-606.

Ozcan-Yilsay, T., Lee, W-J., Horne, D. S. & Lucey, J. A. )2007(. Effect of Trisodium Citrate on Rheological and Physical Properties and Microstructure of Yogurt. J. Dairy Sci, 90:1644-1652.

Ozcan-Yilsay, T., Lucey, J. A. & Horne, D. S.) 2008(. Effect of Tetrasodium Pyrophosphate on the Physicochemical Properties of Yoghurt Gels. J. Dairy Sci, 91:4482-4500.

Payens, T. A. J. )1976(. On the enzyme- triggered clotting of casein: a preliminary account. Neth. Milk Dairy J, 30: 55-59.

Reddy, I. M. & Kinsella, J. E. )1990(. Interaction of β-lactoglobulin with к-casein in micelles as assessed by chymosin hydrolysis: effect of temperature, heating time, of β-lactoglobulin concentration, and pH. Journal of Agriculture and Food Chemistry, 38: 50-58.

Rollema, H. S. )1992(. Casein Association and Micelle Formation in P. F. Fox. Advanced Dairy Chemistry. Vol. 1. Elsevier Ltd.

Schreiber, R. )2001(. Heat-induced modifications in casein dispersions affecting their rennetability. International Dairy Journal, 11: 553–558.

Shalabi, S. I. & Fox, P. F. )1982(. Influence of pH on the rennet coagulation of milk. J. Dairy Res, 49: 153–157.

Udabage, P., McKinnon, I. R. & Augustin, M. A. )2000(. Mineral and casein equilibria in milk: effect of added salts and calcium-chelating agents. J. Dairy Res, 67: 361-370.

Udabage, P., McKinnon, I. R. & Augustin, M. A. )2001(. Effect of Mineral Salts and Calcium Chelating Agents on the Gelation of Rennet Skim milk. J. Dairy Sci, 84:1569-1575.

Van Wazer, J. R. & Callis, C. F. )1958(. Metal complexing by phosphates. Chem. Rev, 58: 1011–1046.

Vasbinder, A. J., Rollema, H. S. & de Kruif, C, G. )2003(. Impaired rennetability of heated milk; study of enzymatic hydrolysis and gelation kinetics. Journal of Dairy Science, 86: 1548–1555.

Visser, J., Minihan, A., Smits, P., Tyan, S. B. & Heertje, I. )1986(. Effect of pH and temperature on the milk salt system. Neth. Milk Dairy J, 40: 351-368.

Walstra, P. & Jenness, R. )1984(. Casein micelles in Dairy chemistry and Physics. New York: John.

Walstra, P. )1999(. Casein sub micelles: do they exist? International Dairy Journal, 9: 189-192.

Walstra, P., Wouters, J. T. M. & Geurts, T. J. )2006(. Dairy Science and Technology. Taylor & Francis Group, LLC.

Wong, N. P. )1988(. Fundamental of Dairy Chemistry, 3^rd ed. Van Nostrand Reinhold, New York.

Yland, G. (2003). Dairy processing handbook. Tetra Pak Processing System AB. 2^nd Edition.