51
|
Jefferies LK, Hansen CL, Steele FM. Translocation and cross-contamination of E. coli O157 in beef eye-of-round subprimal cuts processed with high-pressure needleless injection. J Food Sci 2012; 77:E154-8. [PMID: 22583160 DOI: 10.1111/j.1750-3841.2012.02693.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
UNLABELLED High-pressure needleless injection (HPNI) is an emerging enhancing process where small-diameter, high-velocity bursts of liquid penetrate soft foods at pressures up to 69 MPa. The incidence and depth of translocated surface-inoculated E. coli O157 in HPNI-processed beef eye-of-round subprimal cuts was determined. HPNI translocated E. coli O157 from the surface to the interior of the eye-of-round subprimal cuts with incidence of 40% (± 7%), 25% (± 8%), and 25% (± 8)% for subprimals that had been surface-inoculated with a 4-strain cocktail at 0.5, 1, and 2 log₁₀ CFU/cm² , respectively. The run-off water was collected and found to contain 2, 2, and 3 log₁₀ CFU/mL E. coli O157. The runoff was reused for HPNI of additional subprimals, and this resulted in a cross-contamination incidence of 83% (± 4%), 60% (± 15%), and 37% (± 6)%. Incidence of translocation and cross-contamination was similar at 0 to 1, 1 to 2, 2 to 3, 3 to 4, 4 to 6, and 6 to 8 cm below the inoculated surface. Results indicate that surface microbiota on beef will be carried to the interior of HPNI-processed beef by initial translocation from the surface with the injected fluid and by cross-contamination with recycled fluid. PRACTICAL APPLICATION This research has practical relevance for the beef enhancement process called high-pressure needleless injection. The process's effect on surface bacteria on beef was studied.
Collapse
Affiliation(s)
- Laura K Jefferies
- Dept of Nutrition, Dietetics and Food Sciences Utah State Univ, 8700 Old Main Hill, Logan, UT 84322-8700, USA.
| | | | | |
Collapse
|
52
|
HABIB RAIHAN, WILBEY RODNEYANDREW, GRANDISON ALISTAIRSTEVEN. Pressing technique and its effect on the quality of Dhaka cheese. INT J DAIRY TECHNOL 2012. [DOI: 10.1111/j.1471-0307.2012.00827.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
53
|
Fucà N, McMahon D, Caccamo M, Tuminello L, La Terra S, Manenti M, Licitra G. Effect of brine composition and brining temperature on cheese physical properties in Ragusano cheese. J Dairy Sci 2012; 95:460-70. [DOI: 10.3168/jds.2011-4438] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 09/30/2011] [Indexed: 11/19/2022]
|
54
|
Cheeses with reduced sodium content: Effects on functionality, public health benefits and sensory properties. Trends Food Sci Technol 2011. [DOI: 10.1016/j.tifs.2011.02.003] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
55
|
Gomes A, Cruz A, Cadena R, Celeghini R, Faria J, Bolini H, Pollonio M, Granato D. Manufacture of low-sodium Minas fresh cheese: Effect of the partial replacement of sodium chloride with potassium chloride. J Dairy Sci 2011; 94:2701-6. [DOI: 10.3168/jds.2010-3774] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 02/12/2011] [Indexed: 11/19/2022]
|
56
|
Guo L, Van Hekken DL, Tomasula PM, Shieh J, Tunick MH. Effect of salt on the chemical, functional, and rheological properties of Queso Fresco during storage. Int Dairy J 2011. [DOI: 10.1016/j.idairyj.2010.12.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
57
|
Agarwal S, McCoy D, Graves W, Gerard P, Clark S. Sodium content in retail Cheddar, Mozzarella, and process cheeses varies considerably in the United States. J Dairy Sci 2011; 94:1605-15. [DOI: 10.3168/jds.2010-3782] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 11/20/2010] [Indexed: 11/19/2022]
|
58
|
Albarracín W, Sánchez IC, Grau R, Barat JM. Salt in food processing; usage and reduction: a review. Int J Food Sci Technol 2011. [DOI: 10.1111/j.1365-2621.2010.02492.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
59
|
|
60
|
Costa N, Hannon J, Guinee T, Auty M, McSweeney P, Beresford T. Effect of exopolysaccharide produced by isogenic strains of Lactococcus lactis on half-fat Cheddar cheese. J Dairy Sci 2010; 93:3469-86. [DOI: 10.3168/jds.2009-3008] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 04/18/2010] [Indexed: 11/19/2022]
|
61
|
Floury J, Camier B, Rousseau F, Lopez C, Tissier JP, Famelart MH. Reducing salt level in food: Part 1. Factors affecting the manufacture of model cheese systems and their structure–texture relationships. Lebensm Wiss Technol 2009. [DOI: 10.1016/j.lwt.2009.05.026] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
62
|
Reducing salt and fat content: Impact of composition, texture and cognitive interactions on the perception of flavoured model cheeses. Food Chem 2009. [DOI: 10.1016/j.foodchem.2009.02.027] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
63
|
Johnson ME, Kapoor R, McMahon DJ, McCoy DR, Narasimmon RG. Reduction of Sodium and Fat Levels in Natural and Processed Cheeses: Scientific and Technological Aspects. Compr Rev Food Sci Food Saf 2009; 8:252-268. [DOI: 10.1111/j.1541-4337.2009.00080.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
64
|
Biswas A, Muthukumarappan K, Metzger L. Effect of Ca and P Content, Residual Lactose, and Salt-to-Moisture Ratio on the Model Parameters of Process Cheese Linear Viscoelastic Properties. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2008. [DOI: 10.1080/10942910701558645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
65
|
Chevanan N, Muthukumarappan K. Viscoelastic Properties of Cheddar Cheese: Effect of Calcium and Phosphorus, Residual Lactose, Salt-to-Moisture Ratio and Ripening Time. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2008. [DOI: 10.1080/10942910701580409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
66
|
|
67
|
Biswas A, Muthukumarappan K, Metzger L. Dynamic Rheological Properties of Process Cheese: Effect of Ca and P Content, Residual Lactose, Salt-to-Moisture Ratio and Cheese Temperature. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2008. [DOI: 10.1080/10942910701329369] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
68
|
Laurienzo P, Malinconico M, Mazzarella G, Petitto F, Piciocchi N, Stefanile R, Volpe M. Water Buffalo Mozzarella Cheese Stored in Polysaccharide-Based Gels: Correlation Between Prolongation of the Shelf-Life and Physicochemical Parameters. J Dairy Sci 2008; 91:1317-24. [DOI: 10.3168/jds.2007-0482] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
69
|
Amornkul Y, Henning D. Utilization of Microfiltration or Lactoperoxidase System or Both for Manufacture of Cheddar Cheese from Raw Milk. J Dairy Sci 2007; 90:4988-5000. [DOI: 10.3168/jds.2007-0281] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
70
|
Chevanan N, Muthukumarappan K. Effect of Calcium and Phosphorus, Residual Lactose, and Salt-to-Moisture Ratio on the Melting Characteristics and Hardness of Cheddar Cheese during Ripening. J Food Sci 2007; 72:E168-76. [DOI: 10.1111/j.1750-3841.2007.00330.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
71
|
Awad S. Effect of sodium chloride and pH on the rennet coagulation and gel firmness. Lebensm Wiss Technol 2007. [DOI: 10.1016/j.lwt.2005.10.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
72
|
CALVO M, CASTILLO I, DIAZBARCOS V, REQUENA T, FONTECHA J. Effect of a hygienized rennet paste and a defined strain starter on proteolysis, texture and sensory properties of semi-hard goat cheese. Food Chem 2007. [DOI: 10.1016/j.foodchem.2006.06.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
73
|
|
74
|
Upreti P, Metzger LE. Influence of calcium and phosphorus, lactose, and salt-to-moisture ratio on Cheddar cheese quality: manufacture and composition. J Dairy Sci 2006; 89:420-8. [PMID: 16428612 DOI: 10.3168/jds.s0022-0302(06)72106-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eight Cheddar cheeses with 2 levels of calcium (Ca) and phosphorus (P), residual lactose, and salt-to-moisture ratio (S/M) were manufactured. All cheeses were made using a stirred-curd procedure and were replicated 3 times. Treatments with a high level of Ca and P were produced by setting the milk and drawing the whey at a higher pH (6.6 and 6.3, respectively) compared with the treatments with a low level of Ca and P (pH of 6.2 and 5.7, respectively). The lactose content in the cheeses was varied by adding lactose (2.5% by weight of milk) to the milk for high lactose cheeses, and washing the curd for low lactose cheeses. The difference in S/M was obtained by dividing the curds into halves, weighing each half, and salting at 3.5 and 2.25% of the weight of the curd for high and low S/M, respectively. All cheeses were salted at a pH of 5.4. Modifications in cheese-making protocols produced cheeses with desired differences in Ca and P, residual lactose, and S/M. Average Ca and P in the high Ca and P cheeses was 0.68 and 0.48%, respectively, vs. 0.53 and 0.41% for the low Ca and P cheeses. Average lactose content of the high lactose treatments at d 1 was 1.48% compared with 0.30% for the low lactose treatments. The S/M for the high and low S/M cheeses was 6.68 and 4.77%, respectively. Mean moisture, fat, and protein content of the cheeses ranged from 32.07 to 37.57%, 33.32 to 35.93%, and 24.46 to 26.40%, respectively. The moisture content differed among the treatments, whereas fat and protein content on dry basis was similar.
Collapse
Affiliation(s)
- P Upreti
- MN-SD Dairy Foods Research Center, Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108, USA
| | | |
Collapse
|
75
|
Awad S, Hassan AN, Muthukumarappan K. Application of Exopolysaccharide-Producing Cultures in Reduced-Fat Cheddar Cheese: Texture and Melting Properties. J Dairy Sci 2005; 88:4204-13. [PMID: 16291611 DOI: 10.3168/jds.s0022-0302(05)73106-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Textural, melting, and sensory characteristics of reduced-fat Cheddar cheeses made with exopolysaccharide (EPS)-producing and nonproducing cultures were monitored during ripening. Hardness, gumminess, springiness, and chewiness significantly increased in the cheeses as fat content decreased. Cheese made with EPS-producing cultures was the least affected by fat reduction. No differences in hardness, springiness, and chewiness were found between young reduced fat cheese made with a ropy Lactococcus lactis ssp. cremoris [JFR1; the culture that produced reduced-fat cheese with moisture in the nonfat substance (MNFS) similar to that in its full-fat counterpart] and its full-fat counterpart. Whereas hardness of full-fat cheese and reduced-fat cheese made with JFR1 increased during ripening, a significant decrease in its value was observed in all other cheeses. After 6 mo of ripening, reduced fat cheeses made with all EPS-producing cultures maintained lower values of all texture profile analysis parameters than did those made with no EPS. Fat reduction decreased cheese meltability. However, no differences in meltability were found between the young full-fat cheese and the reduced-fat cheese made with the ropy culture JFR1. Both the aged full- and reduced-fat cheeses made with JFR1 had similar melting patterns. When heated, they both became soft and creamy without losing shape, whereas reduced-fat cheese made with no EPS ran and separated into greasy solids and liquid. No differences were detected by panelists between the textures of the full-fat cheese and reduced-fat cheese made with JFR1, both of which were less rubbery or firm, curdy, and crumbly than all other reduced-fat cheeses.
Collapse
Affiliation(s)
- S Awad
- Minnesota-South Dakota Dairy Foods Research Center, Dairy Science Department, South Dakota State University, Brookings, 57007, USA
| | | | | |
Collapse
|
76
|
Towards the classification of cheese variety and maturity on the basis of statistical analysis of proteolysis data—a review. Int Dairy J 2005. [DOI: 10.1016/j.idairyj.2004.10.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
77
|
Melilli C, Barbano DM, Manenti M, Lynch JM, Carpino S, Licitra G. Lipolysis and Proteolysis in Ragusano Cheese During Brine Salting at Different Temperatures. J Dairy Sci 2004; 87:2359-74. [PMID: 15328257 DOI: 10.3168/jds.s0022-0302(04)73358-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The influence of temperature (12, 15, 18, 21, and 24 degrees C) of saturated brine on lipolysis and proteolysis in 3.8-kg blocks of Ragusano cheese during 24 d of brining was determined. Twenty-six 3.8-kg blocks were made on each day. The cheese making was replicated on 3 different days. All blocks were labeled and weighed prior to brining. One block was sampled and analyzed prior to brine salting. Five blocks were placed into each of 5 different brine tanks at different temperatures. One block was removed from each brine tank after 1, 4, 8, 16, and 24 d of brining, weighed, sampled, and analyzed. Both proteolysis and lipolysis in Ragusano cheese increased with increasing brine temperature (from 12 to 24 degrees C), with the impact of brine temperature on proteolysis and lipolysis becoming progressively larger. Proteolysis was highest in the interior of the blocks where salt in moisture content was lowest and temperature had more impact on proteolysis in the interior position of the block than the exterior position. However, the opposite was true for lipolysis. The total free fatty acid content was higher and temperature had more impact on lipolysis at the exterior position of the block where salt in moisture was the highest. This effect of increased salt concentration on lipolysis was confirmed with direct salted cheeses in a small follow-up experiment. Lipolysis increased with increasing salt in the moisture content of the direct salted cheeses. It is likely that migration of water-soluble FFA from the brine into the cheese and from the interior portion of the cheese to the exterior portion of the cheese also contributed to a higher level of FFA at the exterior portion of the blocks. As brine temperature increased the profile of individual free fatty acids released from triglycerides changed, with the proportion of short-chain free fatty acids increasing with increasing brine temperature. This effect was largest at high salt in moisture content.
Collapse
Affiliation(s)
- C Melilli
- CoRFiLaC, Regione Siciliana, 97100 Ragusa, Italy
| | | | | | | | | | | |
Collapse
|
78
|
Caccamo M, Melilli C, Barbano DM, Portelli G, Marino G, Licitra G. Measurement of gas holes and mechanical openness in cheese by image analysis. J Dairy Sci 2004; 87:739-48. [PMID: 15202659 DOI: 10.3168/jds.s0022-0302(04)73217-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A method to measure the amount of the surface area of cheese slices occupied by gas holes was developed to reflect the relative gas production among different cheeses. A digital camera mounted on a copy stand with lighting was used to make digital images of each slice of cheese. A commercial digital image analysis software program was used and an algorithm was written to measure the area of the image of the cheese slice occupied by holes. The image was cropped and scanned to determine which color channel produced the best image contrast. The MATLAB program allowed the user to eliminate mechanical openness or false holes and then to scan the image to produce a percent distribution of pixels in the image as a function of pixel intensity. The user then determined a threshold value to differentiate pixels that were in holes from those representing areas with no holes. The percentage of the total surface area occupied by holes was calculated. The coefficient of variation of the method ranged from 2.43% with gas holes of about 1% of the surface of the cheese slice to a coefficient of variation of 0.92% with gas holes of about 6.8% of the surface area of the cheese slice. Examples of applications of this method are given for Emmental, Ragusano, and Cheddar cheeses. The method can be used as a tool in research studies to correlate the amount of gas production with manufacturing conditions or as a quality control tool in cheese manufacturing.
Collapse
Affiliation(s)
- M Caccamo
- CoRFiLaC, Regione Siciliana, 97100 Ragusa, Italy
| | | | | | | | | | | |
Collapse
|
79
|
|
80
|
Pastorino J, Hansen CL, McMahon DJ. Effect of Sodium Citrate on Structure-Function Relationships of Cheddar Cheese. J Dairy Sci 2003; 86:3113-21. [PMID: 14594229 DOI: 10.3168/jds.s0022-0302(03)73912-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objective of this study was to determine the effect of sodium citrate on the structure and functionality of Cheddar cheese. The hypothesis was that citrate (sodium citrate) injection would affect cheese properties mainly through its effect on bound calcium (calculated as the difference between total calcium and the water-soluble calcium content of a cheese extract). A 9-kg block of Cheddar cheese was made, vacuum-packaged, and then stored for 2 wk at 4 degrees C. After storage, the cheese was cut into 0.5- to 0.6-kg blocks that were vacuum-packaged and stored for 1 wk at 4 degrees C prior to injection. Cheese blocks were then high-pressure injected with a buffer solution (pH 5.27) containing 40% (wt/ wt) citric acid trisodium dihydrate and 6.25% (wt/wt) anhydrous citric acid, from zero (control) to five times (successive injections performed 24 h apart). Increased citric acid content of cheese from 0.22 (uninjected) to 1.39% (after five injections) caused phosphate solubilization. Thus, the calculated bound phosphate content of cheese decreased from 0.54 to 0.45 mmol/g of protein. However, unexpectedly, the soluble calcium content decreased from 0.34 (control) to 0.28 mmol/g of protein (after five injections), whereas the bound calcium content remained unchanged (0.42 mmol/g of protein). The decrease in soluble calcium probably resulted from the formation and concentration of crystals in the cheese surface, which was not included in samples for analysis, and from the expulsion of serum from within the cheese. Higher concentration of solutes in the water phase of cheese would increase the volume of serum, but the cheese had limited holding capacity and serum was expelled. Citrate injection increased the sodium content of cheese from 0.63 to 0.93%, but it had no effect on cheese pH (5.2). After five injections, the protein matrix expanded, occupying an increased area of cheese matrix (83 vs. 78%). Even though citrate injection had no effect on bound calcium, and thus the rate and extent of cheese flow were unaffected, increased phosphate solubilization, and possibly decreased ionic calcium content, resulted in expansion of the protein matrix and increased cheese hardness.
Collapse
Affiliation(s)
- J Pastorino
- Western Dairy Center, Department of Nutrition and Food Sciences, Utah State University, Logan 84322, USA
| | | | | |
Collapse
|
81
|
Pastorino AJ, Hansen CL, McMahon DJ. Effect of pH on the Chemical Composition and Structure-Function Relationships of Cheddar Cheese. J Dairy Sci 2003; 86:2751-60. [PMID: 14507010 DOI: 10.3168/jds.s0022-0302(03)73871-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objectives of this study were to determine the effect of pH on chemical, structural, and functional properties of Cheddar cheese, and to relate changes in structure to changes in cheese functionality. Cheddar cheese was obtained from a cheese-production facility and stored at 4 degrees C. Ten days after manufacture, the cheese was cut into blocks that were vacuum-packaged and stored for 4 d at 4 degrees C. Cheese blocks were then high-pressure injected one, three, or five times with a 20% (wt/wt) glucono-delta-lactone solution. Successive injections were performed 24 h apart. Cheese blocks were then analyzed after 40 d of storage at 4 degrees C. Acidulant injection decreased cheese pH from 5.3 in the uninjected cheese to 4.7 after five injections. Decreased pH increased the content of soluble calcium and slightly decreased the total calcium content of cheese. At the highest level, injection of acidulant promoted syneresis. Thus, after five injections, the moisture content of cheese decreased from 34 to 31%, which resulted in decreased cheese weight. Lowered cheese pH, 4.7 compared with 5.3, also resulted in contraction of the protein matrix. Acidulant injection decreased cheese hardness and cohesiveness, and the cheese became more crumbly. The initial rate of cheese flow increased when pH decreased from 5.3 to 5.0, but it decreased when cheese pH was further lowered to 4.7. The final extent of cheese flow also decreased at pH 4.7. In conclusion, lowering the pH of Cheddar cheese alters protein interactions, which then affects cheese functionality. At pH greater than 5.0, calcium solubilization decreases protein-to-protein interactions. In contrast, at pH lower than 5.0, the acid precipitation of proteins overcomes the opposing effect caused by increased calcium solubilization and decreased calcium content of cheese, and protein-to-protein interactions increase.
Collapse
Affiliation(s)
- A J Pastorino
- Western Dairy Center, Department of Nutrition and Food Sciences, Utah State University, Logan 84322, USA
| | | | | |
Collapse
|