scholarly journals Association of casein micelle size and enzymatic curd strength and dry matter curd yield

2019 ◽  
Vol 49 (3) ◽  
Author(s):  
Denise Ribeiro de Freitas ◽  
Fernando Nogueira de Souza ◽  
Jamil Silvano de Oliveira ◽  
Diêgo dos Santos Ferreira ◽  
Cristiane Viana Guimarães Ladeira ◽  
...  
Keyword(s):  
Fixed Effects ◽  
Dry Matter ◽  
Linear Models ◽  
Favorable Effect ◽  
Casein Micelle ◽  
Casein Micelles ◽  
Micelle Size ◽  
Milk Protein Content ◽  
Bulk Tank ◽  
Cheese Production

ABSTRACT: The aim of the present study was to explore the association between milk protein content and casein micelle size and to examine the effects of casein micelle size on enzymatic curd strength and dry matter curd yield using reduced laboratory-scale cheese production. In this research, 140 bulk tank milk samples were collected at dairy farms. The traits were analyzed using two linear models, including only fixed effects. Smaller micelles were associated with higher κ-casein and lower αs-casein contents. The casein micellar size (in the absence of the αs-casein and κ-casein effects) did not affect the enzymatic curd strength; however, smaller casein micelles combined with higher fat, lactose, casein and κ-casein contents exhibited a favorable effect on the dry matter curd yield. Overall, results of the present study provide new insights into the importance of casein micelle size for optimizing cheese production.

Influence of homogenization of concentrated milks on the structure and properties of rennet curds

1983 ◽  
Vol 50 (3) ◽  
pp. 341-348 ◽  
Author(s):  
Margaret L. Green ◽  
Richard J. Marshall ◽  
Frank A. Glover
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Size Distribution ◽  
Casein Micelle ◽  
Structure And Properties ◽  
Moisture Retention ◽  
Casein Micelles ◽  
Micelle Size ◽  
Whole Milk ◽  
Milk Casein

SummaryWhole milk was concentrated by ultrafiltration in a plant causing some homogenization of the fat. Comparisons were made with milk concentrated in a plant causing little homogenization and with milk homogenized conventionally. None of the processes appreciably affected the casein micelle size distribution. On rennet treatment of homogenized milk, casein micelle aggregation occurred more slowly, the protein network in the curd was less coarse and the rate of whey loss was reduced, compared with non-homogenized milk at the same concentration. In using concentrated milks for cheesemaking homogenization improved the composition of Cheddar cheese, because of increased fat and moisture retention, but curd fusion was poorer. Some aspects of the texture of the mature cheeses were improved, but the free fatty acid levels were higher. Values for the firmness of curds, formed from milks processed in different ways, did not relate to the extent of aggregation of the casein micelles. It is suggested that the complete cheesemaking process is driven by the tendency of the casein to aggregate.

The structure of casein micelles between pH 5·5 and 6·7 as determined by light-scattering, electron microscopy and voluminosity experiments

1989 ◽  
Vol 56 (3) ◽  
pp. 463-470 ◽  
Author(s):  
Henk J. Vreeman ◽  
Bas W. van Markwijk ◽  
Paula Both
Keyword(s):  
Electron Microscopy ◽  
Light Scattering ◽  
Comparative Data ◽  
Casein Micelle ◽  
Protein Matrix ◽  
Casein Micelles ◽  
Inelastic Light Scattering ◽  
Micelle Size

SummaryHydrodynamic radii from inelastic light-scattering experiments and radii of gyration from Zimm plots give an indication of the change of average casein micelle size when the pH is changed. Combination of the results of both types of measurements gives information on changes in the micelle protein matrix, i.e. changes in the voluminosity.The voluminosity was also determined by the pellet method and by electron microscopy which also provided comparative data on size parameters.

High pressure treatment of bovine milk: effects on casein micelles and whey proteins

2004 ◽  
Vol 71 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Thom Huppertz ◽  
Patrick F Fox ◽  
Alan L Kelly
Keyword(s):  
High Pressure ◽  
Treatment Time ◽  
Whey Proteins ◽  
Bovine Milk ◽  
Casein Micelle ◽  
Pressure Treatment ◽  
Casein Micelles ◽  
High Pressure Treatment ◽  
Micelle Size ◽  
Β Lactoglobulin

Effects of high pressure (HP) on average casein micelle size and denaturation of α-lactalbumin (α-la) and β-lactoglobulin (β-lg) in raw skim bovine milk were studied over a range of conditions. Micelle size was not influenced by treatment at pressures <200 MPa, but treatment at 250 MPa increased micelle size by ∼25%, while treatment at [ges ]300 MPa irreversibly reduced it to ∼50% of that in untreated milk. The increase in micelle size after treatment at 250 MPa was greater with increasing treatment time and temperature and milk pH. Treatment times [ges ]2 min at 400 MPa resulted in similar levels of micelle disruption, but increasing milk pH to 7·0 partially stabilised micelles against HP-induced disruption. Denaturation of α-la did not occur [les ]400 MPa, whereas β-lg was denatured at pressures >100 MPa. Denaturation of α-la and β-lg increased with increasing pressure, treatment time and temperature and milk pH. The majority of denatured β-lg was apparently associated with casein micelles. These effects of HP on casein micelles and whey proteins in milk may have significant implications for properties of products made from HP-treated milk.

Effects of high pressure on some constituents and properties of buffalo milk

2005 ◽  
Vol 72 (2) ◽  
pp. 226-233 ◽  
Author(s):  
Thom Huppertz ◽  
Mathias R Zobrist ◽  
Therese Uniacke ◽  
Vivekk Upadhyat ◽  
Patrick F Fox ◽  
...  
Keyword(s):  
High Pressure ◽  
Buffalo Milk ◽  
Casein Micelle ◽  
Coagulation Time ◽  
Casein Micelles ◽  
Rennet Coagulation ◽  
Micelle Size ◽  
Significant Difference ◽  
Β Lactoglobulin

In this study, effects of high pressure (HP) on some constituents and properties of buffalo milk were examined. HP treatment at 100–600 MPa for 30 min affected casein micelle size only slightly, whereas treatment at 800 MPa increased it by ~35%. Levels of non-micellar αs1- and β-caseins were increased by treatment [ges ]250 MPa, and were highest after treatment at 400–800 MPa. The level of non-micellar calcium increased with increasing pressure up to 600 MPa. The L*-value of the milk decreased gradually with increasing pressure, from ~82 for untreated milk to ~65 for milk treated at 800 MPa. Milk pH was increased by ~0·07 units after treatment at 100–800 MPa, with no significant difference between treatment pressures. Denaturation of α-lactalbumin occurred at pressures [ges ]400 MPa, and reached >90% after treatment at 800 MPa, whereas β-lactoglobulin (β-lg) was denatured >100 MPa, reaching ~100% after treatment at 400 MPa; after treatment [ges ]400 MPa, all β-lg was associated with the casein micelles. The rennet coagulation time of buffalo milk increased with increasing pressure, whereas the strength of the coagulum formed decreased after treatment at 250–800 MPa. Overall, HP treatment affected many constituents and properties of buffalo milk; some of these effects have also been observed in the milk from other species, but the extent of the effects, and the pressure at which they occurred, differed considerably.

Electrophoretic mobility of casein micelles

1979 ◽  
Vol 46 (3) ◽  
pp. 441-451 ◽  
Author(s):  
Donald F. Darling ◽  
John Dickson
Keyword(s):  
Electrophoretic Mobility ◽  
Moving Boundary ◽  
Ionic Composition ◽  
Skim Milk ◽  
Casein Micelle ◽  
Casein Micelles ◽  
Zeta Potentials ◽  
Micelle Structure ◽  
Increase With Increase ◽  
Micelle Size

SummaryA simplified moving boundary electrophoresis technique has been developed for the measurement of the electrophoretic mobility of casein micelles. The zeta potentials of casein micelles from different skim-milk samples were calculated using Henry's equation and shown to decrease with decrease in pH between pH 6.9 and 5.3 and to increase with increase in temperature between 10 and 45 °C. Neither severe heat treatment (up to 135 °C for 51 min) nor centrifugal fractionation of micelles into different micelle size ranges had any significant effect on zeta potential. The ionic composition of the serum phase has been shown to be extremely important in determining the electrophoretic mobility. Casein micelles electrophoresed through milk ultrafiltrate consistently gave a lower mobilities than the same micelles centrifuged through milk centrifugate. The results are discussed in relation to present theories of casein micelle structure; these theories do not accommodate all of the observations.

A model for the assembly of bovine casein micelles from F2 and F3 subunits

1989 ◽  
Vol 56 (3) ◽  
pp. 453-461 ◽  
Author(s):  
Tomotada Ono ◽  
Takayuki Obata
Keyword(s):  
Casein Micelle ◽  
Average Radius ◽  
Casein Micelles ◽  
The Core ◽  
Micelle Size

SummaryCasein micelles were reassembled from mixtures of F2 and F3 subunits, the major subunits of bovine casein micelles, in varying ratios. The average radius of the reassembled micelles was inversely proportional to the F2 content. Based on this relationship, a model for casein micelle assembly is proposed in which the F3 subunit forms the core of the micelle with F2 subunit occurring on the surface. Micelle size can subsequently be defined by the F2 content.

Association of denatured whey proteins with casein micelles in heated reconstituted skim milk and its effect on casein micelle size

2003 ◽  
Vol 70 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Skelte G Anema ◽  
Yuming Li
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Whey Protein ◽  
Volume Fraction ◽  
Whey Proteins ◽  
Skim Milk ◽  
Casein Micelle ◽  
Casein Micelles ◽  
Prolonged Heating ◽  
Micelle Size

When skim milk at pH 6·55 was heated (75 to 100 °C for up to 60 min), the casein micelle size, as monitored by photon correlation spectroscopy, was found to increase during the initial stages of heating and tended to plateau on prolonged heating. At any particular temperature, the casein micelle size increased with longer holding times, and, at any particular holding time, the casein micelle size increased with increasing temperature. The maximum increase in casein micelle size was about 30–35 nm. The changes in casein micelle size were poorly correlated with the level of whey protein denaturation. However, the changes in casein micelle size were highly correlated with the levels of denatured whey proteins that were associated with the casein micelles. The rate of association of the denatured whey proteins with the casein micelles was considerably slower than the rate of denaturation of the whey proteins. Removal of the whey proteins from the skim milk resulted in only small changes in casein micelle size during heating. Re-addition of β-lactoglobulin to the whey-protein-depleted milk caused the casein micelle size to increase markedly on heat treatment. The changes in casein micelle size induced by the heat treatment of skim milk may be a consequence of the whey proteins associating with the casein micelles. However, these associated whey proteins would need to occlude a large amount of serum to account for the particle size changes. Separate experiments showed that the viscosity changes of heated milk and the estimated volume fraction changes were consistent with the particle size changes observed. Further studies are needed to determine whether the changes in size are due to the specific association of whey proteins with the micelles or whether a low level of aggregation of the casein micelles accompanies this association behaviour. Preliminary studies indicated lower levels of denatured whey proteins associated with the casein micelles and smaller changes in casein micelle size occurred as the pH of the milk was increased from pH 6·5 to pH 6·7.

scholarly journals Factor analysis as a tool to estimate association among individual proteins and other milk components with casein micelle size and cheese yield

2017 ◽  
Vol 69 (5) ◽  
pp. 1319-1325
Author(s):  
D.R. Freitas ◽  
F.N. Souza ◽  
L.M. Fonseca ◽  
C.V.G. Ladeira ◽  
V.P.F. Santos ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Milk Proteins ◽  
Milk Composition ◽  
Correlation Spectroscopy ◽  
Production Factor ◽  
Casein Micelle ◽  
Micelle Size ◽  
Milk Components ◽  
The Individual ◽  
Cheese Production

ABSTRACT The present study attempted to identify individual milk proteins and other milk components that are associated with casein micelle size (CMS) and dry matter cheese yield (DMCY) using factor analysis. Here, we used 140 bulk tank milk samples from different farms. Milk composition was determined using a Fourier transform infrared equipament. The individual milk proteins were (αS-casein, β-casein, κ-casein, β-lactoglobulin and α-lactoalbumin) measured by their electrophoretic profile. The CMS was estimated by photon correlation spectroscopy, and the DMCY was determined using reduced laboratory-scale cheese production. Factor analysis partitioned the milk components into three groups that, taken together, explain 68.3% of the total variance. The first factor was defined as “CMS”, while the second as “DMCY” factor, based on their high loadings. The CMS was positively correlated with protein, casein, non-fat solids and αS-casein and negatively associated with κ-casein and β-lactoglubulin. DMCY was positively correlated with fat, protein, casein, total solids and negatively correlated with αs-casein. These results indicate that the variation of individual milk proteins may be an important aspect correlated to milk quality and cheese production.

Disruption and reassociation of casein micelles under high pressure

2006 ◽  
Vol 73 (3) ◽  
pp. 294-298 ◽  
Author(s):  
Thom Huppertz ◽  
Alan L Kelly ◽  
Cornelis G de Kruif
Keyword(s):  
High Pressure ◽  
Casein Micelle ◽  
Casein Micelles ◽  
Micelle Size ◽  
Subsequent Storage ◽  
Induced Changes ◽  
Induced Aggregation

High pressure (HP) treatment affects many constituents of milk (for reviews see Huppertz et al. 2002; Needs, 2002); particular in the properties of casein micelles in HP-treated milk differ considerably from their counterparts in untreated milk. In milk treated at 100–200 MPa, average casein micelle size differs little from that of untreated milk (Needs et al. 2000a; Huppertz et al. 2004a; Regnault et al. 2004; Anema et al. 2005), but micelle size in milk treated at 250 MPa for [ges ]15 min is considerably higher than in untreated milk, probably due to HP-induced aggregation of casein micelles (Huppertz et al. 2004a,b; Regnault et al. 2004); after treatment at 300–800 MPa, micelle size is ~50% lower than that in untreated milk (Needs et al. 2000a; Huppertz et al. 2004a,b; Anema et al. 2005). HP-induced changes in average casein micelle size are irreversible on subsequent storage, except for the increase in micelle size after treatment at 250 MPa (Huppertz et al. 2004a).

scholarly journals Genetic polymorphism of kappa casein and casein micelle size in the Bulgarian Rhodopean cattle breed

2014 ◽  
Vol 30 (4) ◽  
pp. 561-570 ◽  
Author(s):  
P. Hristov ◽  
B. Neov ◽  
H. Sbirkova ◽  
D. Teofanova ◽  
G. Radoslavov ◽  
...  
Keyword(s):  
Genetic Polymorphism ◽  
Light Scattering ◽  
Cattle Breed ◽  
Cow Milk ◽  
Casein Micelle ◽  
Technological Properties ◽  
Casein Micelles ◽  
Milk Samples ◽  
Micelle Size

The present study aimed to compare the size of casein micelle in cow milk sample in function of kappa casein (CSN3) genetic polymorphism. Sixteen cows from Bulgarian Rhodopean cattle breed were genotyped by PCRRFLP analysis. Milk samples from the three found CSN3 genotypes (AB, AA and BB) were employed for the determination of casein micelles size by Dynamic Light Scattering (DLS). The results showed differences in the size and polydispersity of the casein micelles between the milks of cows with different genotypes. Hydrodynamic radii of micelles at a scattering angle of 90?C varied from 80 to 120 nm and polydispersity varied from 0.15 to 0.37. In conclusion casein micelle size of CSN3 AA cows (~ 120 nm) exceed with about 60% cows with (~ 80 nm) and BB genotype (~ 70 nm). These results could be useful for improving technological properties of the milk.

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