See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/282804522
Milk quality for cheese production
Research · October 2015
DOI: 10.13140/RG.2.1.3647.5606
CITATIONS
READS
0
5,487
3 authors, including:
Khaled Nassar
Damanhour University
22 PUBLICATIONS 201 CITATIONS
SEE PROFILE
All content following this page was uploaded by Khaled Nassar on 13 October 2015.
The user has requested enhancement of the downloaded file.
Faculty of Veterinary Medicine and
Animal Science
Milk quality for cheese production
Khaled Sobhy Nassar and Asnake Tenaw Emirie
Department of Animal Nutrition and Management
Literature review • 3 hec • Second cycle, A1N
Milk quality for cheese production
Khaled Sobhy Nassar and Asnake Tenaw Emirie
Supervisor: Sabine Ferneborg
Department of Animal Nutrition and Management
Examiner: Sigrid Agenäs
Department of Animal Nutrition and Management
Credits: 3 hec
Level: Second cycle, A1N
Course title: Biology of Lactation
Course code: HV0099
Cover photo:
Keywords: Milk quality, milk composition, microbial activity, enzymatic activity, somatic cell count (SCC),
cheese production.
Introduction
Bulk milk collected from different farms is used to produce different dairy products
by dairy industries. The milk potential for production of different dairy products
determine the business feasibility of the dairy industry. The process of concentrating
milk constituents, principally fat and protein contents is known as cheese production
[Banks et al., 1981]. Cheese yield is one of the dairy products designed by different
equations that affect the dairy economics (Melilli et al., 2002). Milk composition,
microbiology, somatic cell count, enzymatic activity and the level of contaminant
residues are some of the features that effect the value of milk for cheese
manufacturing (Law & Tamime, 2002).
The objective of this study is to review the factors influencing the quality of milk for
cheese manufacturing.
Literature Review
General milk quality
Milk that fulfills the requirements of its manufacturer and consumer may be
considered as good quality milk (Peri, 2006). High quality dairy products are
produced from good quality raw milk (Lasztity, 2009), and milk quality includes
features such as safety (free from pathogenic organisms and other contaminants that
cause health hazard), purity (free from any extraneous matter), sensory properties
(free from unusual odor, taste, color), chemical composition (normal content of
nutrients and minor components) and physical properties (structure, viscosity, density,
size of fat globules). The cheese manufacturer can measure these aspects by
microbiological, chemical and physical analysis (Law & Tamime, 2002). Milk quality
can be estimated based on clotting parameters by using online equipment (Leitner et
al., 2011b).
Factors affecting the quality of milk for cheese manufacturing
Proteins
Milk composition, principally fat and protein mark the cheese yield potential of milk
(Guo et al., 2004).Caseins and whey proteins are major components of milk proteins
which affect the cheese making process. What we know as cheese is a protein
network formed by precipitation of casein micelles (Scott, 1998) and the cheese yield
potential of milk is basically dependent on casein and fat content of milk (Lucey &
Kelly, 1994).
Cheese yield quality, curd firmness, syneresis rate and moisture retention are affected
by the casein portion of milk (Lawrence, 1991b). Milk with a low casein content
(2.27%), gave lower cheese yield per 100 kg milk (7.38 kg) than milk which was
richer in casein ( 2.48%, yield 7.94 kg ) (Pecorari & Mariani, 1990).The formation of
complexes between whey proteins and casein micelles especially between βlactoglobuline and ĸ-casein increases the firmness of cheese(Gupta & Reuter,1993).
Amino acids, peptides, ammonia and other chemicals are produced during cheese
ripening process when caseins and whey proteins are proteolysed.The cheese flavor is
improved because of the production of these components (Fox & McSweeny, 1998).
Fat
Milk fat is composed of triglycerides, phospholipids, diacylglycerols, sterols, fat
soluble vitamins, carotenoids and traces of free fatty acids but the triglycerides
represent the major part of milk fat (Jensen, 2002).
The effect of fat on cheese quality varies depending on the initial mass of fat and
content of fat in milk. Texture, flavor, mouth feel and consistency are predominantly
influenced by the fat content of cheese (Bylund, 1995).Cheese with high fat content is
less firm and elastic while cheese with low fat content is harder and less smooth
(Emmons et al., 1980) due to the increase in cross linking between the curd (Ohern
&Tuckey, 1969).
In commercial cheese production the fat to casein proportion need to be considered,
because the ratio of the two constituents affect the cheese yield (Labuschagne, 1982).
Increase in fat is likely to lower the rate of curd syneresis, increase whey retention and
also contributes to determine the cheese yield for a quota that is relatively greater than
its own corresponding weight (Gilles & Lawrence, 1985).
Water
Moisture in cheese affects the shelf life, the cheese yield and the texture of cheese.
Cheese with high moisture content is liable to microbial spoilage as moisture
improves the growth and multiplication of microorganisms. Milk with high moisture
content results in a higher cheese yield (Scott, 1998).
Microbial activity of milk
Milk is a good medium for the growth of microorganisms because it is rich in
nutrients necessary for the growth of microbes. The flora in raw milk, the processing
conditions and contamination after heat treatment affect the microbiological quality of
milk and its products (Varga, 2007).
Emphasis should be given on microbiological analysis of milk and dairy products
because of the presence of bacteria of major public health importance in milk. Some
of these bacteria species include Salmonella spp., Listeria monocytogenes,
Campylobacter jejuni, Yersinia enterocolitica, pathogenic strains of Escherichia coli
and enter toxigenic strains of Staphylococcus aureus (Varga, 2007).
Gram-negative bacteria, Psychrotrophic bacteria, Coliforms, Lactic acid bacteria,
Yeasts, and Molds can effect spoilage of dairy products (Varga, 2007). When the cell
number of Psychrotrophic bacteria in the raw milk is higher than 106 cfu /ml, the yield
and quality of cheese curd decreases (Fairbairn & Law, 1986).
Poor eye development and nonexistence of flavor in the Swiss cheese is as a result of
inhibition of Propionic bacteria and Lactobacillus fermentum activity by
Eubacterium spp (Nath & Kostak, 1985). The yeasty flavor in cheese is as a result of
alcohol and CO 2 development by yeasts (Horwood et al., 1987).
Milk-contact surfaces and hands of dairy workers are the most important
contaminants of milk which have significant influence on the quality of cheese even if
starter culture, rennet, calcium chloride, brine solution also have some effects on the
quality of cheese (Robinson & Tamime, 2002).
Somatic cell count
The somatic cell count exhibits the quality of milk, the udder health and variations in
milk composition (Hamann, 2005). Even though an udder has high levels of somatic
cell count at the end of lactation and during colostral period (Dulin, et al., 1983), the
udder is seeming healthy if it contains an somatic cell count (SCC) < 100,000 cells/ml
and free from mastitis causing microorganisms (Hamann, 2005).
During mastitis casein and milk fat are broken down by proteases and lipases
(Barbano et al., 2006) and increases in concentrations of whey proteins, but decreases
in concentrations of milk fat, lactose and casein (Auldist et al., 1995).
Cheese made from milk of high somatic cell count has low curd firmness, low cheese
yield, high fat and casein loss in whey, poor sensory quality (Ma et al., 2000) and also
low growth of lactic acid bacteria because of the antibacterial compounds contained in
white blood cells (Ali et al., 1980).
Enzymatic activity of milk
Bacterial contamination, somatic cell present in milk and milk itself are sources of
milk enzymes which play significant role in yield and quality of cheese (Law &
Tamime, 2002).
Proteinases hydrolyse caseins to water-soluble peptides that are lost in whey and not
recovered during the manufacture of products such as cheese (Kelly et al., 2006).
Plasmin is a proteolytic enzyme that breaks down β-casein into γ-casein and smaller
polypeptides (Auldist et al., 1996) and αs 1 - and αs 2 -casien (McSweeny et al., 1993),
and thus influence the coagulation because of its negative impact on casein, and
finally leads to less cheese yield and quality output (Srinivasan & Lucey, 2002,
Zachos et al., 1992).
The production of mono, diacylglycerols and free fatty acids by lipolysis in cheese
and milk lead to the emergence of non-desired flavors such as rancid, soapy, and
bitter (Law & Tamime, 2002).
Conclusion
The quality of cheese is mainly affected by the quality of milk. The milk quality for
cheese production is influenced by factors such as milk composition, the levels of
indigenous contaminants, enzyme activity, somatic cell count and levels of chemical
residues. Casein and fat content has a role in determining cheese yield potential of
milk. The yield of cheese is directly related to the content of casein in milk. Fat
influences texture, flavour, mouthfeel and consistency of cheese whereas the casein
fraction of cheese is responsible for curd firmness, syneresis rate and moisture
retention rate of cheese. Milk with high composition of casein and fat, low levels of
enzymes and low somatic cell count is generally good quality milk for cheese
manufacturing.
References
Ali, A. E., Andrews, A.T. and Cheeseman, G. C. 1980. Influence of elevated somatic cell count on
casein distribution and cheese making. Journal of Dairy Research. 47:393–400.
Auldist, M. J., Coats, S., Rogers, G. L. and McDowell, G. H. 1995. Changes in the composition of milk
from healthy and mastitic dairy cows during the lactation cycle. Australian Journal of Experimental
Agriculture. 35: 427-436.
Auldist, M. J., Coats, S., Sutherlands, B. J., Mayes, J. J., McDowell, G. H. and Rogers Graeme, L.
1996. Effects of somatic cell count and stage of lactation on raw milk composition and the yield and
quality of Cheddar cheese. Journal of Dairy Research. 63: 269–280.
Banks J.M., Banks W., Muir D.D. and Wilson A.G., 1981. Cheese yield: composition does matter.
Dairy Ind. Int. (46), 15, 17, 19, 21-22.
Barbano, D.M, Ma, Y. and Santos, M.V. 2006. Influence of raw milk quality on fluid milk shelf life.
Journal of Dairy Science.89: E15- E19.
Bylund, G. 1995. Dairy processing Handbook. Lund, Sweden: Tetra pak processing systems. PP 18-19,
25-28, 31-32, 290- 292, 296-297 and 373.
Dulin, A. M., Paape, M. J., Schultze, W. D. and Weinland, B. T. 1983. Effect of parity, stage of
lactation, and intramammary infection on concentration of somatic cells and cytoplasmic particles in
goat milk. Journal of Dairy Science. 66: 2426-2433.
Emmons, D.B., Kalab, M., Larmond, E. and Lowrie, R.J. 1980. Milk gel structure. X. Texture and
microstructure in Cheddar cheese made using whole homogenized low-fat milk. J Tex Stud, 11:15-23.
Gupta, V.K. and Reuter, W. 1993. Firmness and melting quality of processed cheese foods with added
whey protein concentrates. Lait, 73: 381–388.
Fairbairn, D. J. and Law, B. A. 1986. Proteinases of psychrotrophic bacteria: their production,
properties, effects and control. Journal of Dairy Research. 53: 139–177.
Fox, P.F. and McSweeny, P.L.H. 1998 .Dairy chemistry and biochemistry. London: Blackie Academic
and professionals. PP 49, 347-378 and 421.
Frank, J. F. 2001. Milk and dairy products. In Doyle, M. P., Beuchat, L. R., and Montville, T. J. (Eds.),
Food microbiology: fundamentals and frontiers (2nd ed., pp. 111–126). Washington, DC: Am. Soc.
Microbiol.
Gilles J. and Lawrence R.C. 1985. The yield of cheese. New Zealand Journal of Dairy Science, and
Technology. 20: 205-214.
Guo, M., Park, Y.W., Dixon, P.H., Gilmore, J.A. and Kindstedt, P.S. 2004. Relationship between the
yield of cheese (Chèvre) and chemical composition of goat milk. Small Ruminant Research. 52: 103–
107.
Hamann, J. 2005. Diagnosis of mastitis and indicators of milk quality. In: Mastitis in dairy production:
current knowledge and future solutions. Hogeveen H (ed). Wageningen, Wageningen Academic
Publishers. pp 82-90.
Horwood, J. F., Stark, W., and Hull, H. H. 1987. A fermented, yeasty flavour defect in Cheddar cheese.
Australian Journal of Dairy Technology. 42: 25–26.
Jensen, R.G. 2002. The composition of bovine milk lipids: January 1995 to December 2000. Journal of
Dairy Science. 85: 295–350.
Kelly, A.L., O’Flaherty, F. and Fox, P.F. 2006. Indigenous proteolytic enzymes in milk: a brief
overview of the present state of knowledge. International Dairy Journal, 16: 563–572.
Labuschagne J.H. 1982. Influenza della composizione chimica del latte sulla qualità del formaggio. Il
Latte. 7: 294-298.
Lasztity, R. 2009. Milk and milk products. Food Quality and Standers, 2: 156-168.
Law, B.A. and Tamime, A.Y.2010.The quality of milk for cheese manufacture. In: Technology of
cheese making. Second edition. Guinees, T.P and O’Brien, B.Wiley.UK: chapter (1) pages 1-67.
Lawrence, R.C. 1991b. Relationship between milk protein genotypes and cheese yield capacity.
Monograph on Factors Affecting the Yield of Cheese. International Dairy Federation, Brussels,
Belgium, Monogr. Special Issue 9301, pp. 121–127.
Leitner, G., Lavi, Y., Merin, U., Lemberskiy-Kuzin, L. and Katz, G. 2011b. On-line evaluation of milk
quality according to coagulation properties for its optimal distribution for industrial applications.
Journal of Dairy Science. 94: 2923–2932.
Lucey J. and Kelly J. 1994. Cheese yield. Society of Dairy Technology, 47(1): 1-14.
Ma, Y., Ryan, C., and Barbano, D.M. 2000. Effects of somatic cell count on quality and shelf-life of
pasteurized fluid milk. Journal of Dairy Science.83: 264–274.
McSweeny, P. L. H., Olson, N. F., Fox, P. F., Healy, A., and Hojrup, P. 1993. Proteolytic specificity of
plasmin on bovine αs 1 -casein. Food Biotechnology. 7:143–158.
Melilli, C., Lynch J.M., Caprino, S., Barbano, D.M., Licitra, G. and Cappa, A. 2002. An empirical
method for prediction of cheese yield. Journal of Dairy Science 85: 2699–2704.
Nath, K. R. and Kostak, B. J. 1985. Etiology of white spot defect in Swiss cheese made from
pasteurized milk. Journal of Food Protection. 49: 718–723.
Ohern, J.A, and Tuckey, S.L. 1969. Relation of flavor development in Cheddar cheese to chemical
changes in fat of the cheese. Journal of Dairy Science, 52:598-607.
Pecorari, M.and Mariani, P. 1990. Caseina, attitudine alla coagulazione del latte, resa e qualità del
formaggio. Sci. Tecn. Latt-cas. 41: 225-244.
Peri, C. 2006. The universe of food quality. Food Quality and Preference, 17: 3–8.
Robinson, R.K. and Tamime, A.Y. 2002. Maintaining a clean working environment. In: Richard K (ed)
Dairy microbiology handbook. Wiley, New York, pp 561–590.
Scott, R. 1998. Cheese making practice. New York: Kluwer Academics. PP 11-14, 37-38, 123-127,
277-279,281-284 and 359-361.
Srinivasan, M., and Lucey, J. A. 2002. Effects of added plasmin on the formation and rheological
properties of rennet-induced skim milk gels. Journal of Dairy Science. 5:1070–1078.
Varga, L. 2007. Microbiological quality of commercial dairy products. Communicating Current
Research and Educational Topics and Trends in Applied Microbiology A. Méndez-Vilas (Ed.). 487494.
Zachos, T., Politis, I., Gorewit, R. C., and Barbano, D. M. 1992. Effect of mastitis on plasminogen
activator activity of milk somatic cells. Journal of Dairy Research. 59:461–467.
View publication stats