Effect of starters on proteolysis of Graviera Kritis cheese

Abstract

Four cheesemakings of Graviera Kritis cheese (chee ses A-D) were made from a mixture of ewe' s and goal' s milk. Three of these were made with mixed cultures of thermophilic + propionic or mesophilic + thermophilic + propionic starters, while the fourth one was made traditionally without starter cultures. The effect of increasing the temperature of ripening was also determined. The pH 4.4-soluble nitrogen (SN) and trichloroacetic acid (TCA-SN) fractions increased mainly during the warm room ripening. The use of starters caused no significant differences in the ratios of nitrogen fractions of the four mature cheeses (age> 90 d), whatever the ripening temperature. Nitrogen fractions were significantly correlated with cheese age. At 180 d of ripening, the percentage of pH 4.4-SN in total nitrogen (TN) was 20.7-22.8 % and that of TCA-SN in TN was 19.1-19.3 %. Polyacrylamide gel electrophoretic (PAGE) results showed that chymosin and plasmin action was intense during the maturation of the cheeses. The proportion of hydrophilic peptides was higher in the water soluble nitrogen (WSN) fraction of the cheeses made with starter cultures at both ripening temperatures. Free amino acids (FAA) were not significantly different in the four types of cheeses, reaching 208-246 mmol·kg-' after 180 d of ripening. The changes in total FAA and in the most abundant FAA during the ripening were significantly correlated with chee se age (r > 0.940). The ripening at higher temperature increased the main FAA and the total FAA content in ail types of cheeses, in particular in the chee se made without starter cultures. © InralElsevier, Paris. * Correspondence and reprints. mg@auadec.aua.gr Graviera Kritis cheese / starter culture / proteolysis Résumé -Effet des levains sur la protéolyse du fromage Graviera Kritis. Quatre fabrications de fromages Graviera Kritis ont été réalisées à partir d'un mélange de lait de brebis et de chèvre. Trois d'entre elles ont été ensemencées en levains mixtes, lactiques thermophiles + propioniques ou lactiques mésophiles + thermophiles + propioniques et la dernière a été réalisée traditionnellement, sans levains. Les fractions azotées solubles à pH 4,4 (pH 4,4-SN) et dans l'acide trichloroacétique 12 % The starters used and the corresponding names of the chee ses were as follows: Cheese A: Streptococcus thermophilus + Lactobacillus helveticus (1: 1) + Propionibacterium freudenreichii subsp. shermanii Cheese B: Lactococcus Lactis subsp. lactis + Lactococcus lactis subsp. cremoris + Str. thermophilus + Lb. helveticus (1: 1: 10:2) + P. freudenreichii subsp. shermanii Cheese C: Le. lactis subsp. lactis + Le. lactis subsp. cremoris + Str. thermophilus + Lb. helveticus (2.5:2.5: 1:1) + P. freudenreichii subsp. shermanii Cheese D: Without starters

Effect of natamycin-containing coating on the evolution of biochemical and microbiological parameters during the ripening and storage of ovine hard-Gruyère-type cheese

“…In general, at 90 d, the SN/TN ratios of the present study were lower than those reported for this cheese type by Moatsou, Kandarakis, Georgala, Alichanidis, and Anifantakis (1999). Average SN/TN values for marketed Graviera Kritis cheeses was 17.3 ± 3.8% (Nega & Moatsou, 2012) and values for this index approximately 20% or more have been reported for experimental cheeses (Moatsou et al, 1999(Moatsou et al, , 2004.…”

Effect of different manufacturing parameters on the characteristics of Graviera Kritis cheese

“…Soluble nitrogenous fractions were similar to those reported for Graviera Kritis cheese by Moatsou et al (1999). The greatest part of the water-soluble nitrogen (> 64%) consisted of nitrogen soluble at 12% TCA, which corresponds to medium-and small-sized peptides with 2 -20 amino acids (Yvon et al 1989).…”

“…The characteristics of Graviera Kritis cheese during ripening have been studied by Kandarakis et al . (1998) and Moatsou et al (1999).…”

Effect of milk pasteurization and curd scalding temperature on proteolysis in Malatya, a Halloumi-type cheese

“…Differences in the levels of pH 4.6-SN between raw and pasteurized milk cheeses were significant (P < 0.05) after 30 days of ripening and these differences became greater as the ripening advanced. This may be attributed to the proteolytic activity of non-starter lactic acid bacteria that dominate toward the end of ripening [18,23]. The expected influence of starter used in the manufacture of P cheeses on the pH 4.6-SN was observed in the inhibitory effect of scalding.…”