Application of Exopolysaccharide-Producing Cultures in Reduced-Fat Cheddar Cheese: Composition and Proteolysis

Abstract

Proteolysis during ripening of reduced fat Cheddar cheeses made with different exopolysaccharide (EPS)-producing and nonproducing cultures was studied. A ropy strain of Lactococcus lactis ssp. cremoris (JFR1) and capsule-forming nonropy and moderately ropy strains of Streptococcus thermophilus were used in making reduced-fat Cheddar cheese. Commercial Cheddar starter was used in making full-fat cheese. Results showed that the actual yield of cheese made with JFR1 was higher than that of all other reduced-fat cheeses. Cheese made with JFR1 contained higher moisture, moisture in the nonfat substance, and residual coagulant activity than all other reduced-fat cheeses. Proteolysis, as determined by PAGE and the level of water-soluble nitrogen, was also higher in cheese made with JFR1 than in all other cheeses. The HPLC analysis showed a significant increase in hydrophobic peptides (causing bitterness) during storage of cheese made with JFR1. Cheese made with the capsule-forming nonropy adjunct of S. thermophilus, which contained lower moisture and moisture in the nonfat substance levels and lower chymosin activity than did cheese made with JFR1, accumulated less hydrophobic peptides. In conclusion, some EPS-producing cultures produced reduced-fat Cheddar cheese with moisture in the nonfat substance similar to that in its full-fat counterpart without the need for modifying the standard cheese-making protocol. Such cultures might accumulate hydrophobic (bitter) peptides if they do not contain the system able to hydrolyze them. For making high quality reduced-fat Cheddar cheese, EPS-producing cultures should be used in conjunction with debittering strains.

Effect of Different Packaging Materials on the Physico-Chemical, Microbiological and Sensory Quality of Thirattupal during Storage

“…moisture content, acidity and pH were determined as per methods given in BIS (1981), BIS (1980b) and Awad et al, (2005), respectively. The method prescribed by Deeth et al, (1975) was used to estimate the FFA content of Thirattupal.…”

Changes in transcription profiles reflect strain contributions to defined cultures of Lactococcus lactis subsp. cremoris during milk fermentation

“…Additional attributes such as bacteriophage resistance and production of inhibitory substances are also considered for the selection of strains (Cleveland et al 2001). Correct proportions of capsule-forming and ropy strains increase elasticity of the product by releasing optimal concentrations of different exopolysaccharides (EPS) to enhance cheddar rheological properties (Dabour et al 2006), but many of these EPSproducing strains need to be mixed with strains possessing the capacity to remove bitter peptides (Awad et al 2005). However, improper microbial activities can lead to acidification problems, rheological defects, or products with atypical flavors caused by overproduction of molecules such as p-cresol, phenylethanol, phenylacetaldehydes, indole, and skatole (Christensen et al 1999).…”

Some perspectives on the use of cheese as a food ingredient

“…Over the past 10 years there have been numerous studies on the impact of using EPS-producing cultures on the texture of low fat Mozzarella (e.g., [69]) or reduced fat Cheddar cheeses [3,12]. The formation and structural properties of the various types of EPS produced by lactic acid bacteria have been reviewed [15,84].…”