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Title
Abstract
Ready to be utilised various substrates in ripening cheeses make possible growing of secondary microflora, especially lactobacilli strains. Due to protection effect of fat and protein Non-starter lactic acid bacteria survive pasteurisation of milk and start growing up quite quickly, especially in milk heat treated several times (termisation, bactofugation, ultrafiltration, pasteurisation). The subject of examination was Gouda cheese, that was produced from milk after all the above mentioned heat treatments with use of working leaven multiplied in buffer base. During this experiment besides starter cultures addition of selected lactobacilli (L. casei, L. acidophilus, L. casei ssp.rhamnosus) was used for experimental cheese production. Cheeses were exposed to chemical analysis immediately after salting. Changes of acidity and extend of paracasein degradation (soluble N, amino acid N and peptide N) was determined during the cheese ripening. Paracasein degradation in control cheese took place under the influence of rennet, enzymes synthesised by starter cultures and non-starter lactic acid bacteria. However in the experimental Gouda cheese except non-starter lactic acid bacteria, Lactobacillus strains added to cheese milk were also active. Addition of lactobacilli for Gouda cheese production had no influence on cheese acidity immediately after manufacturing and during ripening. Considerable differences in water content (40.6 – 42.6%) were found. Comparison of paracasein degradation dynamics in control and experimental cheese was possible due to referring separate forms of nitrogen compounds content to total N content. Higher increases (about 2%) of peptide N, amino acid N and soluble N compounds content were determined in experimental cheese produced with Lactobacillus strains addition than in control ones. Higher, in comparison to the rest experimental cheeses, content of amino acid N and peptide N compounds in cheeses with L. acidophilus resulted of the higher (on average of 1%) content of water.
Keywords
Gouda cheese, Lactobacillus, proteolysis, nitrogen compounds