foodsystFood systemsПищевые системы2618-97712618-7272Федеральный научный центр пищевых систем им. В.М. Горбатова РАН10.21323/2618-9771-2019-2-3-4-8foodsyst-43Research ArticleСтатьиSTUDY OF THE ENZYMATIC STAGE OF MILK GELATION: CHANGES IN VISCOSITY AND MICROSTRUCTURESTUDY OF THE ENZYMATIC STAGE OF MILK GELATION: CHANGES IN VISCOSITY AND MICROSTRUCTURESmykovI. T.SmykovI. T.

Igor T. Smykov — doctor of technical sciences, chief research scientist.

Krasnoarmeysky Boulevard, 19, Uglich, Yaroslavl Region,  152613

Igor T. Smykov — doctor of technical sciences, chief research scientist.

Krasnoarmeysky Boulevard, 19, Uglich, Yaroslavl Region, 152613 

i_smykov@mail.ruAll-Russian Scientific Research Institute of Butter — and Cheesemaking — Branch of V. M. Gorbatov Federal Research Center for Food Systems of RASРоссияAll-Russian Scientific Research Institute of Butter — and Cheesemaking — Branch of V. M. Gorbatov Federal Research Center for Food Systems of RASRussian Federation2019051020192348Copyright © Smykov I.T., 20192019Smykov I.T.Smykov I.T.This work is licensed under a Creative Commons Attribution 4.0 License.https://www.fsjour.com/jour/article/view/43

The article presents the results of experimental joint studies of changes in the viscosity and microstructure of milk at the enzymatic stage of gelation. Based on the statistical processing of the array of research results, it was determined that the viscosity change at this stage is not monotonic, as it is usually stated, but two-stage in the middle part and S-shaped, preceding the gel point, at its end. It was found that the S-shaped change in viscosity at the end of the enzymatic stage of milk coagulation coincides with changes in the microstructure of casein micelles and reflects the existence of a cooperative conformational phase transition in casein molecules of micelle clusters. A description of the possible mechanism of this phase transition is proposed. It was noted that the moment of the S-shaped change in the milk viscosity at the enzymatic gelation stage and the corresponding cooperative phase transition in casein micelles are a physical reflection of the gel point. The research results provide a better understanding of the mechanism of enzymatic coagulation of milk in a cheesemaking tank.

The article presents the results of experimental joint studies of changes in the viscosity and microstructure of milk at the enzymatic stage of gelation. Based on the statistical processing of the array of research results, it was determined that the viscosity change at this stage is not monotonic, as it is usually stated, but two-stage in the middle part and S-shaped, preceding the gel point, at its end. It was found that the S-shaped change in viscosity at the end of the enzymatic stage of milk coagulation coincides with changes in the microstructure of casein micelles and reflects the existence of a cooperative conformational phase transition in casein molecules of micelle clusters. A description of the possible mechanism of this phase transition is proposed. It was noted that the moment of the S-shaped change in the milk viscosity at the enzymatic gelation stage and the corresponding cooperative phase transition in casein micelles are a physical reflection of the gel point. The research results provide a better understanding of the mechanism of enzymatic coagulation of milk in a cheesemaking tank.

milkrennet gelationenzymatic stagecasein micellesviscositymicrostructuremilkrennet gelationenzymatic stagecasein micellesviscositymicrostructureReferencesWalstra, P., Wouters, J. T. M., Geurt, T. J. (2006). Dairy Science and Technology. 2nd Ed. — CRC Press. — 808 p. ISBN 1420028014Walstra, P., Wouters, J. T. M., Geurt, T. J. (2006). Dairy Science and Technology. 2nd Ed. — CRC Press. — 808 p. ISBN 1420028014Croguennec, T., Jeantet, R., Brulé, G. (2008). Fondements physicochimiques de la technologie laitière. Paris: Lavoisier. — 161 p. ISBN 9782743018641Croguennec, T., Jeantet, R., Brulé, G. (2008). Fondements physicochimiques de la technologie laitière. Paris: Lavoisier. — 161 p. ISBN 9782743018641Troch, T., Lefébure, É., Baeten, V., Colinet, F., Gengler N., Sindic, M. (2017). Cow milk coagulation: process description, variation factors and evaluation methodologies. A review. Biotechnology, Agronomy, Society and Environment, 21(4), 276–287.Troch, T., Lefébure, É., Baeten, V., Colinet, F., Gengler N., Sindic, M. (2017). Cow milk coagulation: process description, variation factors and evaluation methodologies. A review. Biotechnology, Agronomy, Society and Environment, 21(4), 276–287.Lucey, J. A. (2011). Rennet-induced coagulation of milk. In book: Fuquay, J. W., Fox, P. F., McSweeney, P. L. H. (eds) Encyclopedia of Dairy Sciences, V. 1, 2nd edn. Academic, Oxford, pp 579–584. ISBN 978–0–12–374402–9Lucey, J. A. (2011). Rennet-induced coagulation of milk. In book: Fuquay, J. W., Fox, P. F., McSweeney, P. L. H. (eds) Encyclopedia of Dairy Sciences, V. 1, 2nd edn. Academic, Oxford, pp 579–584. ISBN 978–0–12–374402–9Sinaga, H., Bansal, N., Bhandari, B. (2017). Gelation properties of partially renneted milk. International Journal of Food Properties, 20(8), 1700–1714. DOI: 10.1080/10942912.2016.1193515Sinaga, H., Bansal, N., Bhandari, B. (2017). Gelation properties of partially renneted milk. International Journal of Food Properties, 20(8), 1700–1714. DOI: 10.1080/10942912.2016.1193515Fox, P. F., Guinee, T. P., Cogan, T. M., McSweeney, P. L. H. (2017). Fundamentals of Cheese Science, Sec. Ed., Springer. —799 p. ISBN 978–1– 4899–7679–6Fox, P. F., Guinee, T. P., Cogan, T. M., McSweeney, P. L. H. (2017). Fundamentals of Cheese Science, Sec. Ed., Springer. —799 p. ISBN 978–1– 4899–7679–6Walstra, P., Bloomfield, V. A., Jason Wei, G., Jenness, R. (1981). Effect of chymosin action on the hydrodynamic diameter of casein micelles. BBA — Protein Structure, 669(2), 258–259. DOI: 10.1016/0005– 2795(81)90249-XWalstra, P., Bloomfield, V. A., Jason Wei, G., Jenness, R. (1981). Effect of chymosin action on the hydrodynamic diameter of casein micelles. BBA — Protein Structure, 669(2), 258–259. DOI: 10.1016/0005– 2795(81)90249-XHorne, D. S., Davidson C. M. (1993). Direct observation of decrease in size of casein micelles during the initial stages of renneting of skim milk. International Dairy Journal, 3(1), 61–71. DOI: 10.1016/0958– 6946(93)90076-CHorne, D. S., Davidson C. M. (1993). Direct observation of decrease in size of casein micelles during the initial stages of renneting of skim milk. International Dairy Journal, 3(1), 61–71. DOI: 10.1016/0958– 6946(93)90076-CFox, P. F. and Guinee T. P. (2013). Cheese Science and Technology. In book: Milk and Dairy Products in Human Nutrition. Y. W. Park and G. F. Haenlein (eds). p. 357–389. ISBN 978–92–5–107863–1Fox, P. F. and Guinee T. P. (2013). Cheese Science and Technology. In book: Milk and Dairy Products in Human Nutrition. Y. W. Park and G. F. Haenlein (eds). p. 357–389. ISBN 978–92–5–107863–1Smykov, I. T. (2015). Kinetics of Milk Gelation. Part I. Coagulation Mechanism. In book: Rheology: principles, applications and environmental impacts, Nova Science Publ., New York, pp 65–82. ISBN 978– 1–63482–223–7Smykov, I. T. (2015). Kinetics of Milk Gelation. Part I. Coagulation Mechanism. In book: Rheology: principles, applications and environmental impacts, Nova Science Publ., New York, pp 65–82. ISBN 978– 1–63482–223–7Surkov, B. A., Klimovskii, I. I., Krayushkin, V. A. (1982). Turbidimetric study of kinetics and mechanism of milk clotting by rennet. Milchwissenschaft, 37, 393–395.Surkov, B. A., Klimovskii, I. I., Krayushkin, V. A. (1982). Turbidimetric study of kinetics and mechanism of milk clotting by rennet. Milchwissenschaft, 37, 393–395.Arai, M., Kuwajima, K. (2000). Role of the molten globule state in protein folding. Advances in Protein Chemistry, 53, 209–282. DOI: 10.1016/ S0065–3233(00)53005–8Arai, M., Kuwajima, K. (2000). Role of the molten globule state in protein folding. Advances in Protein Chemistry, 53, 209–282. DOI: 10.1016/ S0065–3233(00)53005–8Farrell, H. M. Jr., Qi, P. X., Brown, E. M., Cooke, P. H., Tunick, M. H., Wickham, E. D., Unruh, J. J. (2002). Molten Globule Structures in Milk Proteins: Implications for Potential New Structure-Function Relationships. Journal of Dairy Science, 85(3), 459–471. DOI: 10.3168/jds.S0022– 0302(02)74096–4Farrell, H. M. Jr., Qi, P. X., Brown, E. M., Cooke, P. H., Tunick, M. H., Wickham, E. D., Unruh, J. J. (2002). Molten Globule Structures in Milk Proteins: Implications for Potential New Structure-Function Relationships. Journal of Dairy Science, 85(3), 459–471. DOI: 10.3168/jds.S0022– 0302(02)74096–4Smykov, I. T. (2018). Milk curd cutting time determination in cheesemaking. Food systems, 1(2), 16–20. DOI: 10.21323/2618–9771–2018–1–2– 12–20 (In Russian)Smykov, I. T. (2018). Milk curd cutting time determination in cheesemaking. Food systems, 1(2), 16–20. DOI: 10.21323/2618–9771–2018–1–2– 12–20 (In Russian)The composition and properties of milk as raw materials for the dairy industry. (1986). Handbook ed. by Kostin Ya. I. Moscow: Agropromizdat. — 240 p. (In Russian)The composition and properties of milk as raw materials for the dairy industry. (1986). Handbook ed. by Kostin Ya. I. Moscow: Agropromizdat. — 240 p. (In Russian)Zhang, Y., Liu, D., Liu, X., Hang, F., Zhou, P., Zhao, J., Chen, W. (2018) Effect of temperature on casein micelle composition and gelation of bovine milk. International Dairy Journal, 78, 20–27. DOI: 10.1016/j.idairyj.2017.10.008Zhang, Y., Liu, D., Liu, X., Hang, F., Zhou, P., Zhao, J., Chen, W. (2018) Effect of temperature on casein micelle composition and gelation of bovine milk. International Dairy Journal, 78, 20–27. DOI: 10.1016/j.idairyj.2017.10.008Gonçalves, B. J., Pereira, C. G., Lago, A. M. T., Gonçalves, C. S., Giarola, T. M. O., Abreu, L. R., Resend, J. V. (2017). Thermal conductivity as influenced by the temperature and apparent viscosity of dairy products. Journal of Dairy Science, 100(5), 3513–3525. DOI: 10.3168/jds.2016– 12051Gonçalves, B. J., Pereira, C. G., Lago, A. M. T., Gonçalves, C. S., Giarola, T. M. O., Abreu, L. R., Resend, J. V. (2017). Thermal conductivity as influenced by the temperature and apparent viscosity of dairy products. Journal of Dairy Science, 100(5), 3513–3525. DOI: 10.3168/jds.2016– 12051Smykov I. T., Myagkonosov D. S., Smirnov V. V. (2004). Study of the protein particles structuring in milk. Dairy Industry, 9, 58–60. (In Russian)Smykov I. T., Myagkonosov D. S., Smirnov V. V. (2004). Study of the protein particles structuring in milk. Dairy Industry, 9, 58–60. (In Russian)De Kruif, C. G. (1998). Supra-aggregates of Casein Micelles as a Prelude to Coagulation. Journal of Dairy Science, 81(11), 3019–3028. DOI: 10.3168/ jds.S0022–0302(98)75866–7De Kruif, C. G. (1998). Supra-aggregates of Casein Micelles as a Prelude to Coagulation. Journal of Dairy Science, 81(11), 3019–3028. DOI: 10.3168/ jds.S0022–0302(98)75866–7Totosaus, A., Montejano, J. G., Salazar, J. A., Guerrero, I. (2002). A review of physical and chemical protein-gel induction. International Journal of Food Science and Technology, 37(6), 589–601. DOI: 10.1046/j.1365– 2621.2002.00623.xTotosaus, A., Montejano, J. G., Salazar, J. A., Guerrero, I. (2002). A review of physical and chemical protein-gel induction. International Journal of Food Science and Technology, 37(6), 589–601. DOI: 10.1046/j.1365– 2621.2002.00623.xPtitsyn, O. B. (1995). Molten globule and protein folding. Advances in Protein Chemistry, 47, 83–229.Ptitsyn, O. B. (1995). Molten globule and protein folding. Advances in Protein Chemistry, 47, 83–229.Finkelstein, A. V., Ptitsyn, O. B. (2005). Protein Physics: Lecture Course. 3rd ed. Moscow: KDU. — 455 p (In Russian)Finkelstein, A. V., Ptitsyn, O. B. (2005). Protein Physics: Lecture Course. 3rd ed. Moscow: KDU. — 455 p (In Russian)Protein Structure, Stability and Folding (2001). Murphy K. P. ed., Totowa: Humana Press Inc. — 252 p.Protein Structure, Stability and Folding (2001). Murphy K. P. ed., Totowa: Humana Press Inc. — 252 p.Marangoni, C. (1869). Sull’espansione delle goccie d’un liquido galleggianti sulla superficie di altro liquido (On the expansion of a droplet of a liquid floating on the surface of another liquid) (Pavia, Italy: fratelli Fusi (Fusi brothers).Marangoni, C. (1869). Sull’espansione delle goccie d’un liquido galleggianti sulla superficie di altro liquido (On the expansion of a droplet of a liquid floating on the surface of another liquid) (Pavia, Italy: fratelli Fusi (Fusi brothers).

The authors declare that there are no conflicts of interest present.