29th Annual Marschall Italian Cheese Seminar
Three 375 lb vats of cultured low moisture pan skim Mozzarella cheese were produced from the same batch of standardized milk and rennet, but using three different rod (Lactobacillus bulgaricus - Marschall ProduciS - Thennorod) and coccus (Streptococcus thermophilus - Mar chall Product - Thennococcus) ratios (9R:IC, 5R:5C, and !R:9C). The total volume and total colony fonning units of culture added was kept constant for all ratios (i.e., I 02 ml/375 I b). Cheese was made with the ·'no-brine·· chee e making method using a I06°F (41° ) cook temperature, 6.4 draw pH *whey), 5.25 milling pH, and 135°F (57°C) stretching temperature. Cheese making was replicated on three different days as a 3 X 3 Latin square des ign. Tit ratable acid ity increase and pH decrease were slower, while make time was longer wi th the 9R: I C ratio. The number of both rod and coccus per gram increased during cheese making, but differential enumeration of rod and coccus revealed that coccus was the dominant organi sm in the curd at milling regardless of initial rod:coccus ratio added to the milk. The number of viable coccus was not decrea ed by stretching and remained con tan! during 50 days of refrigerated storage. The number of viable rods seemed to decrease as a result of stretching and may continue to decrease during storage. The amount of inoculation (given contant ripening time) may be as important or more important than the ratio of rod-to-coccus.
There were no significant differences in initial chemical composition (moi lure. fat, protein, salt) and pH among cheeses made using different rod:coccus ratios. soluble protein content (i.e., pH 4.6 acetate soluble -extent of proteolysis; 12% TCA oluble depth of proteolysis) in the chee e increased with time for all cheeses, but proteolysis of cheese with higher rod:coccus ratio increased at a faster rate. Rod:coccu ratio had a greater impact on 12% TCA soluble protein, than on pH 4.6 so luble protein. The highest rod:coccus ra tio produced more 12% TCA soluble nitrogen during refrigerated storage. Thus, the higher the number of viable rods present during cheese manufacturing, the greater the depth of proteolysis.
Various Authors, "Proceedings from the 29th Annual Marschall Italian Cheese Seminar" (1992). Cheese Industry Conference. Paper 17.