Cheeses during cheese ripening

Different authors used RP-HPLC and UV detection to monitor peptide formation during cheese ripening [174-178], providing valuable information about proteolysis. When large hydrophobic peptide need to be separated an lEC represents the best choice [179]. Nevertheless, the identification of these peptides is essential for the complete understanding of the proteolytic process. The peptides eluted from the LC column can be subjected to ESl-MS for molecular weight determination and MS/MS for amino acid sequence determination, which allow rapid peptide identification [172]. HPLC-ESl-MS and MS/MS techniques have been successfully used for peptide mass fingerprint purposes for sequence analysis of purified albumin from Theobroma cacao seeds [180,181]. 

Effect of milk heating on peptide formation during cheese ripening... 

Gripon, J. C., Desmazaud, M. J., Le Bars, D. and Bergere, J. L. 1977. Role of proteolytic enzymes of Streptococcus lactis, Penicillium roqueforti, and Penicillium caseicolum during cheese ripening. J. Dairy Sci., 60, 1532-1538. 

Majeed, G. H. 1984. Survival of porcine pepsin during Cheddar cheesemaking and its effect on casein during cheese ripening. Ph.D. Thesis. Utah State University, Logan. 

During cheese ripening, proteases associated with starter culture organisms are released into cheese after cell lysis (Law et al. 1974). The proteolytic activity associated with lysed lactic streptococci is necessary for proper flavor development in Cheddar and other cheese varieties. The role of streptococcal proteases and peptidases appears to be production of flavor compound precursors such as methionine and other amino acids, rather than direct production of flavor compounds (Law et al. 1976A). Additional discussion of cheese ripening is presented in Chapter 12. 

Desmazeau, M. J. and Gripon, J. C. 1977. General mechanism of protein breakdown during cheese ripening. Milchwissenschaft 32, 731-734. 

Lipolysis is considered to be an important biochemical event during cheese ripening and the current knowledge have been discussed in detail (Collins et al., 2003, 2004 McSweeney and Sousa, 2000). The formation of short-chain FFAs by the lipolysis of milk fat by lipases is a desirable reaction in many cheese types (e.g., mold-ripened cheeses). The catabolism of FFAs, which is a secondary event in the ripening process, leads to the formation of volatile flavor compounds such as lactones, thioesters, ethyl esters, alkanols, and hydroxyl fatty acids. The contributions of lipolysis to the flavor of bacterially ripened cheeses are limited. 

Proteolysis is the most important of the three primary events occurring during cheese ripening. Due to the complexity of proteolysis, including the catabolism of amino acids and their contribution to cheese flavor, this topic has been the focus of several studies. A comprehensive review of the... 

FIGURE 5.1 Overview of proteolysis during cheese ripening. 

FIGURE 5.2 Analysis scheme for assessment of proteolysis during cheese ripening, modified from Sousa et al. (2001). Analytical techniques are highlighted in bold with shading. 

Mazerrolles, G., Devaux, M. F., Duboz, G., Duployer, M. H., Riou, N. M., and Dufour, E. (2001). Infrared and fluorescence spectroscopy for monitoring protein structure and interaction changes during cheese ripening. Lait 81, 509-527. 

Skeie, S., Feten, G., Almpy, T., 0stlie, FI., and Isaksson, T. (2006). The use of near infrared spectroscopy to predict selected free amino acids during cheese ripening. Int. Dairy. J. 16, 236-242. 

ACE-inhibitory peptides are produced during the manufacture of dairy products, e.g., secondary proteolysis during cheese ripening. The ACE-inhibitory activity in cheese was mainly associated with the low molecular mass peptide fraction. 

During cheese ripening, the population of starter bacteria generally decreases while the number of non-starter lactic acid bacteria (NSLAB) generally increases these changes are well documented for many full-fat rennet-curd cheese varieties, (e.g., Cheddar) (Cromie et al., 1987 Jordan and Cogan, 1993 McSweeney et al., 1993 Lane et al., 1997 Haque et al., 1997 Beresford and Williams, 2004). 

Lawrence, R.C., Creamer, L.K., Gilles, J. 1987. Texture development during cheese ripening. /. Dairy Sci. 70, 1748-1760. 

In enzyme modified cheese (EMC) the natural cheese is modified with enzymes or micro-organisms which accelerate the changes that occur normally during cheese ripening. Production of cheese on industrial scale is an expensive process. EMC processes have been developed in order to shorten and thus cheapen the process. 

Because of the complexity of proteolytic patterns during cheese ripening, chemometrics has recently been proposed as an objective approach for the evaluation of proteolytic profiles and data interpretation. 

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