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The effect of heat treatment and skimming on precipitate formation in caprine and bovine milks

Published online by Cambridge University Press:  19 November 2014

Zorana N Miloradovic*
Affiliation:
Faculty of Agriculture, Institute of Food Technology and Biochemistry, University of Belgrade, Nemanjina 6, 11081 Belgrade, Serbia
Nemanja V Kljajevic
Affiliation:
Faculty of Agriculture, Institute of Food Technology and Biochemistry, University of Belgrade, Nemanjina 6, 11081 Belgrade, Serbia
Snezana T Jovanovic
Affiliation:
Faculty of Agriculture, Institute of Food Technology and Biochemistry, University of Belgrade, Nemanjina 6, 11081 Belgrade, Serbia
Tanja R Vucic
Affiliation:
Faculty of Agriculture, Institute of Food Technology and Biochemistry, University of Belgrade, Nemanjina 6, 11081 Belgrade, Serbia
Ognjen D Macej
Affiliation:
Faculty of Agriculture, Institute of Food Technology and Biochemistry, University of Belgrade, Nemanjina 6, 11081 Belgrade, Serbia
*
*For correspondence; e-mail: zorana@agrif.bg.ac.rs

Abstract

Caprine and bovine milks have a similar overall gross composition, but vary considerably in the ratios of their casein components. These differences in colloidal casein micelles could affect directly or indirectly the heat stability of caprine and bovine milks at their natural pH. In the present work, the differences in colloidal stability of caprine and bovine milk have been studied by analysing the effect of heat treatment and skimming on precipitation of proteins. Raw and heated milk samples (70 °C/5 min, 80°C/5 min and 90°C/5 min) were centrifuged at 600, 2000, and 4500 g. The amount of precipitate formed after skimming was measured and the protein composition of both precipitates and supernatants analysed using the SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) and densitometry. In caprine milk, the heat treatment prior to skimming had a statistically significant effect on protein precipitation. Centrifugal force had a statistically significant effect on amount of precipitate for both milks, but the amount was 2 to 4 times higher for caprine milk. When defatting the milk for electrophoresis, a centrifugal force of 600 g appeared to be the most appropriate, in order to avoid protein loss and a possible error in the interpretation of results. Results of this study could also serve as the basis for further investigations on adjusting the skimming conditions for caprine milk in industrial dairy processing environment.

Type
Research Article
Copyright
Copyright © Proprietors of Journal of Dairy Research 2014 

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References

Anema, SG & Stanley, DJ 1998 Heat-induced, pH-dependent behaviour of protein in caprine milk. International Dairy Journal 8 917923Google Scholar
AOAC 1990 Official Methods of Analysis, 15th edition, pp. 841842. Washington, DC: Association of Official Analytical Chemists, 807–809 ppGoogle Scholar
Calvo, MM & Espinoza, NA 1999 Syneresis rate of cow's, ewe's, and goat's curd. Effect of thermal treatment and ultrafiltration. Journal of Agricultural and Food Chemistry 47 883886CrossRefGoogle ScholarPubMed
Calvo, MM, Amigo, L, Olano, A, Martin, PJ & Ramos, M 1989 Effect of thermal treatments on the determination of bovine milk added to ovine or caprine milk. Food Chemistry 32 99108Google Scholar
Devold, TG, Brovold, MJ, Langsrud, T & Vegarud, GE 2000 Size of native and heated casein micelles, content of protein and minerals in milk from Norwegian Red Cattle – effect of milk protein polymorphism and different feeding regimes. International Dairy Journal 10 313323Google Scholar
Donato, L & Guyomarc'h, F 2009 Formation and properties of the whey protein/κ-casein complexes in heated skim milk – a review. Dairy Sci. Technol. 89 329Google Scholar
García-Risco, MR, Ramos, M & López-Fandiño, R 2002 Modifications in milk proteins induced by heat treatment and homogenization and their influence on susceptibility to proteolysis. International Dairy Journal 12 679688Google Scholar
Guo, MR, Wang, S, Li, Z, Qu, J, Jin, L & Kindsted, PS 1998 Ethanol stability of goat's milk. International Dairy Journal 8 5760Google Scholar
Havea, P 1998 Studies on heat-induced interactions and gelation of whey protein. PhD thesis, Palmerston North, New Zealand: Massey UniversityGoogle Scholar
Henry, G, Mollé, D, Morgan, F, Fauquant, J & Bouhallab, S 2001 Heat-induced covalent complex between casein micelles and β-lactoglobulin from goat's milk: identification of an involved disulfide bond. Journal of Agricultural and Food Chemistry 50 185191Google Scholar
International Dairy Federation 1981 Determination of Fat Content. Gerber Butyrometers. Milk. IDF Standard No. 105 Brussels, BelgiumGoogle Scholar
International Dairy Federation 1987 Determination of Total Solids Content. Milk, Cream and Evaporated Milk. FIL-IDF Standard No. 021B Brussels, BelgiumGoogle Scholar
Laemmli, UK 1970 Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227 680685Google Scholar
Law, AJR & Leaver, J 2000 Effect of pH on the thermal denaturation of whey proteins in milk. Journal of Agricultural and Food Chemistry 48 672679Google Scholar
Lieske, B, Konrad, G & Faber, W 1997 A new spectrophotometric assay for native β-lactoglobulin in raw and processed bovine milk. International Dairy Journal 7 805812Google Scholar
Lindmark-Månsson, H, Timgren, A, Aldén, G & Paulsson, M 2005 Two-dimensional gel electrophoresis of proteins and peptides in bovine milk. International Dairy Journal 15 111121Google Scholar
Livney, YD, Corredig, M & Dalgleish, DG 2003 Influence of thermal processing on the properties of dairy colloids. Current Opinion in Colloid & Interface Science 8 359364Google Scholar
Moatsou, G, Samolada, M, Panagiotou, P & Anifantakis, E 2004 Casein fraction of bulk milks from different caprine breeds. Food Chemistry 87 7581Google Scholar
Montilla, A, Balcones, E, Olano, A & Calvo, MM 1995 Influence of heat treatments on whey protein denaturation and rennet clotting properties of cow's and goat's milk. Journal of Agricultural and Food Chemistry 43 19081911CrossRefGoogle Scholar
Morand-Fehr, P, Boutonnet, JP, Devendra, C, Dubeuf, JP, Haenlein, GFW, Holst, P, Mowlem, L & Capote, J 2004 Strategy for goat farming in the 21st century. Small Ruminant Research 51 175183Google Scholar
Morgan, F, Micault, S & Fauquant, J 2001 Combined effect of whey protein and aS1-casein genotype on the heat stability of goat milk. International Journal of Dairy Technology 54 6468Google Scholar
Park, YW 2006 Goat milk-chemistry and nutrition. In Handbook of Milk of Non-bovine Mammals, pp. 59106 (Eds Park, YW & Haenlein, GFW). New York: Blackwell PublishingGoogle Scholar
Park, YW 2007 Rheological characteristics of goat and sheep milk. Small Ruminant Research 68 7387Google Scholar
Park, YW & Guo, M 2006 Goat milk products: types of products, manufacturing technology, chemical composition and marketing. In Handbook of Milk of Non-bovine Mammals, pp. 3458 (Eds Park, YW & Haenlein, GFW). New York: Blackwell PublishingGoogle Scholar
Pesic, MB, Barac, MB, Stanojevic, SP, Ristic, NM, Macej, OD & Vrvic, MM 2012 Heat induced casein–whey protein interactions at natural pH of milk: a comparison between caprine and bovine milk. Small Ruminant Research 108 7786Google Scholar
Rafael, DD & Calvo, MM 1996 Deposit formation during heat treatment of cows’, goats’ and ewes’ milks. Journal of Dairy Research 63 635638Google Scholar
Raynal, K & Remeuf, F 1998 The effect of heating on physicochemical and renneting properties of milk: a comparison between caprine, ovine and bovine milk. International Dairy Journal 8 695706Google Scholar
Raynal-Ljutovac, K, Park, YW, Gaucheron, F & Bouhallab, S 2007 Heat stability and enzymatic modifications of goat and sheep milk. Small Ruminant Research 68 207220Google Scholar
Sandra, S & Dalgleish, DG 2007 The effect of ultra high-pressure homogenization (UHPH) on rennet coagulation properties of unheated and heated fresh skimmed milk. International Dairy Journal 17 10431052Google Scholar
Shuiep, ETS, Giambra, IJ, El Zubeir, IEYM & Erhardt, G 2013 Biochemical and molecular characterization of polymorphisms of αs1-casein in Sudanese camel (Camelus dromedarius) milk. International Dairy Journal 28 8893CrossRefGoogle Scholar
Silanikove, N, Leitner, G, Merin, U & Prosser, CG 2010 Recent advances in exploiting goat's milk: quality, safety and production aspects. Small Ruminant Research 89 110124Google Scholar
Tuinier, R & de Kruif, CG 2002 Stability of casein micelles in milk. Journal of Chemical Physics 117 1290Google Scholar