UHT İçme Sütlerinde Jelleşme Sorunu: Enzimlerin Etkisi

Sütün raf ömrünü uzatmak için endüstride kullanımı en yaygın ısıl işlem yöntemi UHT (Ultra High Temperature - ÇokYüksek Sıcaklık Uygulaması) işlemidir. Ancak, depolama sırasında enzimatik ve fiziksel etkilere bağlı olarak meydanagelen jel oluşumu UHT içme sütlerinin raf ömrünü kısaltmaktadır. Çiğ sütte bulunan psikrotrofik bakteriler tarafındanüretilen yüksek sıcaklığa dirençli proteinazlar ile sütün yapısında doğal olarak bulunan plazmin ve plazmin sistemienzimleri UHT içme sütlerinde jel oluşumuna neden olmaktadır. Söz konusu enzimler, sütün en önemli proteini olankazeine farklı şekilde etki etmekte ve UHT içme sütlerinde farklı metabolitler üretmektedir. Bu derlemede, UHT içmesütlerinde meydana gelen jelleşmenin oluşum mekanizması ve oluşumunu etkileyen enzimler hakkında bilgi verilmesiamaçlanmaktadır.

Gelation Problem in UHT Milk: Effect of Enzymes

The most prevalent heat treatment method used in the industry to extend shelf life of milk is UHT (Ultra High Temperature) process. However, the gel formation occurred depending on enzymatic and physical effects during storage shortens the shelf life of UHT milk. Heat-stable proteinases produced by psychotropic bacteria, and the native plasmin and plasmin system enzymes in raw milk cause gel formation in UHT milk. These enzymes differently affect casein, which is the most important milk protein, and produce different metabolites in UHT milk. In this review, it is aimed to give information about the mechanism of gelation and enzymes affecting its formation in UHT milk.

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[1] Ünal, R., Besler, H.T. (2008). Beslenmede sütün önemi. Sağlık Bakanlığı Yayın No:727. Ankara.
[2] Hodgkinson, A.J., Wallace, O.A.M., Boggs, I., Broadhurst, M., Prosser, C.G. (2018). Gastric digestion of cow and goat milk: Impact of infant and young child in vitro digestion conditions. Food Chemistry, 245, 275-281.
[3] Claeys, W.L., Cardoen, S., Daube, G., De Block, J., Dewettinck, K., Dierick, K., De Zutter, L., Huyghebaert, A., Imberechts, H., Thiange, P. (2013). Raw or heated cow milk consumption: Review of risks and benefits. Food Control, 31(1), 251-262.
[4] Muñoz, I., Gou, P., Picouet, P.A., Barlabé, A., Felipe, X. (2018). Dielectric properties of milk during ultra-heat treatment. Journal of Food Engineering, 219, 137-146.
[5] Anonim, (2000). Türk Gıda Kodeksi Çiğ Süt ve Isıl İşlem Görmüş İçme Sütleri Tebliği. T.C. Resmi Gazete. 23964 (2000/6), Ankara.
[6] Gunnar, R., Jens, K. (2006). Extended shelf life milk-advances in technology. International Journal of Dairy Technology, 59(2), 85-96.
[7] Anonim, (2018). Süt ve süt ürünleri üretimi miktarı ve değişim oranları. Türkiye İstatistik Kurumu, Ankara.
[8] Richards, M., De Kock, H.L., Buys, E.M. (2014). Multivariate accelerated shelf-life test of low fat UHT milk. International Dairy Journal, 36(1), 38-45.
[9] Urgu, M., Saatli, T.E., Türk, A., Koca, N. (2017). Isıl işlem görmüş içme sütlerinde (Pastörize, UHT ve Laktozsuz UHT Süt) hidroksimetilfurfural içeriğinin belirlenmesi. Akademik Gıda, 15(3), 249-255.
[10] Richards, M., Buys, E.M., De Kock, H.L. (2016). Survival analysis, consumer perception and physico-chemical analysis of low fat UHT milk stored for different time periods. International Dairy Journal, 57, 56-61.
[11] D'Incecco, P., Rosi, V., Cabassi, G., Hogenboom, J.A., Pellegrino, L. (2018). Microfiltration and ultrahigh-pressure homogenization for extending the shelf-storage stability of UHT milk. Food Research International, 107, 477-485.
[12] Deeth, H. (2017). High Temperature Proocessing of Milk and Milk Products. John Wiley & Sons, Chichester, UK, 261p.
[13] Datta, N., Deeth, H. (2001). Age gelation of UHT milk-a review. Food and Bioproducts Processing, 79(4), 197-210.
[14] Wolz, M., Mersch, E., Kulozik, U. (2016). Thermal aggregation of whey proteins under shear stress. Food Hydrocolloids, 56, 396-404.
[15] Loveday, S.M. (2016). β-Lactoglobulin heat denaturation: A critical assessment of kinetic modelling. International Dairy Journal, 52, 92-100.
[16] Vaghela, K.D., Chaudhary, B.N., Mehta, B.M. (2018). A review on proteolysis rate in UHT milk: Its mechanism, pattern, assessment and enzymatic changes during storage. Research & Reviews: Journal of Dairy Science and Technology, 6(3), 1- 16.
[17] McMahon, D.J. (1996). Age-gelation of UHT milk: Changes that occur during storage, their effect on shelf life and the mechanism by which age-gelation occurs. Heat treatments and alternative methods. IDF Symposium, Vienna Austria, 315p.
[18] Malmgren, B., Ardö, Y., Langton, M., Altskär, A., Bremer, M.G., Dejmek, P., Paulsson, M. (2017). Changes in proteins, physical stability and structure in directly heated UHT milk during storage at different temperatures. International Dairy Journal, 71, 60-75.
[19] Andrews, A., Cheeseman, G. (1972). Properties of aseptically packed ultra-high-temperature milk: II. Molecular weight changes of the casein components during storage. Journal of Dairy Research, 39(3), 395-408.
[20] Venkatachalam, N., McMahon, D.J., Savello, P. (1993). Role of protein and lactose interactions in the age gelation of ultra-high temperature processed concentrated skim milk. Journal of Dairy Science, 76(7), 1882-1894.
[21] Chavan, R.S., Chavan, S.R., Khedkar, C.D., Jana, A.H. (2011). UHT milk processing and effect of plasmin activity on shelf life: A review. Comprehensive Reviews in Food Science and Food Safety, 10(5), 251-268.
[22] Manji, B., Kakuda, Y. (1988). The role of protein denaturation, extent of proteolysis, and storage temperature on the mechanism of age gelation in a model system. Journal of Dairy Science, 71(6), 1455-1463.
[23] Alves, M.P., Salgado, R.L., Eller, M.R., Dias, R.S., Oliveira de Paula, S., Fernandes de Carvalho, A. (2018). Temperature modulates the production and activity of a metalloprotease from Pseudomonas fluorescens 07A in milk. Journal of Dairy Science, 101(2), 992-999.
[24] Samaržija, D., Zamberlin, Š., Pogačić, T. (2012). Psychrotrophic bacteria and milk and dairy products quality. Mljekarstvo, 62(2), 77-95.
[25] Akan, E., Yerlikaya, O., Kınık, Ö. (2014). Psikrotrof bakterilerin çiğ süt ve süt ürünleri kalitesine etkisi. Akademik Gıda, 12(4), 68-78.
[26] Xin, L., Meng, Z., Zhang, L., Cui, Y., Han, X., Yi, H. (2017). The diversity and proteolytic properties of psychrotrophic bacteria in raw cows' milk from North China. International Dairy Journal, 66, 34-41.
[27] von Neubeck, M., Baur, C., Krewinkel, M., Stoeckel, M., Kranz, B., Stressler, T., Fischer, L., Hinrichs, J., Scherer, S., Wenning, M. (2015). Biodiversity of refrigerated raw milk microbiota and their enzymatic spoilage potential. International Journal of Food Microbiology, 211, 57-65.
[28] Stoeckel, M., Lidolt, M., Achberger, V., Glück, C., Krewinkel, M., Stressler, T., von Neubeck, M., Wenning, M., Scherer, S., Fischer, L. (2016). Growth of Pseudomonas weihenstephanensis, Pseudomonas proteolytica and Pseudomonas sp. in raw milk: Impact of residual heat-stable enzyme activity on stability of UHT milk during shelf-life. International Dairy Journal, 59, 20-28.
[29] Sørhaug, T., Stepaniak, L. (1997). Psychrotrophs and their enzymes in milk and dairy products: Quality aspects. Trends in Food Science & Technology, 8(2), 35-41.
[30] Matéos, A., Guyard-Nicodème, M., Baglinière, F., Jardin, J., Gaucheron, F., Dary, A., Humbert, G., Gaillard, J.L. (2015). Proteolysis of milk proteins by AprX, an extracellular protease identified in Pseudomonas LBSA1 isolated from bulk raw milk, and implications for the stability of UHT milk. International Dairy Journal, 49, 78-88.
[31] Ertan, H., Cassel, C., Verma, A., Poljak, A., Charlton, T., Aldrich-Wright, J., Omar, S.M., Siddiqui, K.S., Cavicchioli, R. (2015). A new broad specificity alkaline metalloprotease from a Pseudomonas sp. isolated from refrigerated milk: Role of calcium in improving enzyme productivity. Journal of Molecular Catalysis B: Enzymatic, 113, 1-8.
[32] Baglinière, F., Matéos, A., Tanguy, G., Jardin, J., Briard-Bion, V., Rousseau, F., Robert, B., Beaucher, E., Gaillard, J.L., Amiel, C., Humbert, G., Dary, A., Gaucheron, F. (2013). Proteolysis of ultra high temperature-treated casein micelles by AprX enzyme from Pseudomonas fluorescens F induces their destabilisation. International Dairy Journal, 31(2), 55-61.
[33] Martins, M.L., de Araújo, E.F., Mantovani, H.C., Moraes, C.A., Vanetti, M.C.D. (2005). Detection of the apr gene in proteolytic psychrotrophic bacteria isolated from refrigerated raw milk. International Journal of Food Microbiology, 102(2), 203-211.
[34] Machado, S.G., Heyndrickx, M., De Block, J., Devreese, B., Vandenberghe, I., Vanetti, M.C.D., Van Coillie, E. (2016). Identification and characterization of a heat-resistant protease from Serratia liquefaciens isolated from Brazilian cold raw milk. International Journal of Food Microbiology, 222, 65-71.
[35] Baglinière, F., Jardin, J., Gaucheron, F., De Carvalho, A.F., Vanetti, M.C.D. (2017). Proteolysis of casein micelles by heat-stable protease secreted by Serratia liquefaciens leads to the destabilisation of UHT milk during its storage. International Dairy Journal, 68, 38-45.
[36] McMahon, D.J., Brown, R.J. (1984). Enzymic coagulation of casein micelles: A review. Journal of Dairy Science, 67(5), 919-929.
[37] Bhatt, H., Cucheval, A., Coker, C., Patel, H., Carr, A., Bennett, R. (2017). Effect of micellar structure of casein and its modification on plasmin-induced hydrolysis. International Dairy Journal, 75, 75-82. [38] Aydemir, O., Dervişoğlu, M., Temiz, H. (2008). Süt alkali proteinazı plazmin. Gıda Dergisi, 33(5), 235- 240.
[39] Ismail, B., Nielsen, S. (2010). Invited review: plasmin protease in milk: current knowledge and relevance to dairy industry. Journal of Dairy Science, 93(11), 4999-5009.
[40] Saint Denis, T., Humbert, G., Gaillard, J.L. (2001). Heat inactivation of native plasmin, plasminogen and plasminogen activators in bovine milk: A revisited study. Le Lait, 81(6), 715-729.
[41] Tolkach, A., Kulozik, U. (2007). Reaction kinetic pathway of reversible and irreversible thermal denaturation of beta-lactoglobulin. Le Lait, 87(4-5), 301-315.
[42] Stoeckel, M., Lidolt, M., Stressler, T., Fischer, L., Wenning, M., Hinrichs, J. (2016). Heat stability of indigenous milk plasmin and proteases from Pseudomonas: A challenge in the production of ultra-high temperature milk products. International Dairy Journal, 61, 250-261.
[43] Burbrink, C.N., Hayes, K.D. (2006). Effect of thermal treatment on the activation of bovine plasminogen. International Dairy Journal, 16(6), 580-585.
[44] Kohlmann, K., Nielsen, S., Ladisch, M. (1991). Effects of a low concentration of added plasmin on ultra-high temperature processed milk. Journal of Dairy Science, 74(4), 1151-1156.
[45] Rauh, V.M., Sundgren, A., Bakman, M., Ipsen, R., Paulsson, M., Larsen, L.B., Hammershøj, M. (2014). Plasmin activity as a possible cause for age gelation in UHT milk produced by direct steam infusion. International Dairy Journal, 38(2), 199- 207.
[46] Rauh, V.M., Johansen, L.B., Ipsen, R., Paulsson, M., Larsen, L.B., Hammershøj, M. (2014). Plasmin activity in UHT milk: Relationship between proteolysis, age gelation, and bitterness. Journal of Agricultural and Food Chemistry, 62(28), 6852- 6860.
[47] Zhang, C., Bijl, E., Hettinga, K. (2018). Destabilization of UHT milk by protease AprX from Pseudomonas fluorescens and plasmin. Food Chemistry, 263, 127-134.
[48] Anonim, (2018). Research Theme 6-Proteases in UHT Milk. https://www.wur.nl/upload_mm/4/0/8/d661dad0- 5e6b-491d-9283- 7a04047ba98b_6%20Proteases%20in% 20UHT%20 milk.pdf Erişim tarihi: 29.06.2018 [49] Datta, N., Deeth, H.C. (2003). Diagnosing the cause of proteolysis in UHT milk. LWT-Food Science and Technology, 36(2), 173-182.