MOZZARELLA CHEESE - IMPACT OF 3 COMMERCIAL CULTURE STRAINS ON COMPOSITION, PROTEOLYSIS AND FUNCTIONAL-PROPERTIES

The impact of different lactobacillus culture strains on chemical comp osition, proteolysis and functional properties of mozzarella cheese du ring refrigerated storage was determined. Three vats of cheese were ma de in one day using three culture strains of rods (L. delbrueckii sap. bulgaricus; R110 and R160, and L. helveticus; R150). Cheesemaking was replicated on three different days using randomised block design. Cha nges in pH and titratable acidity during cheesemaking were significant ly slower with the R110 than R150 or R160. No detectable differences o ccurred in general cheese composition because of culture strain. There was a significant interaction of culture strain with storage time on cheese pH. No significant differences in the rates of increase in the nitrogen soluble in pH 4.6 acetate buffer or 12% TCA were observed. St orage time had a much greater impact on changes in TPA parameters than culture strain. Meltability increased with storage time for all chees e with a significant interaction of culture strain and storage time. A fter 15 days' storage, meltability of cheeses were similar, but by 50 days cheeses made with R110 had lower meltability than those made with R150 or R160. On pizza baking at 15 days, the colour and blistering w ere similar far ail strains. However, after 50 days' refrigerated stor age, the cheese made with R110 strain showed more intensive brown colo ur and a larger number of smaller-size blisters than cheeses made with R150 or R160. Thus, selection of lactobacillus culture strain for moz zarella cheesemaking can influence the cheese's functional properties.