Effects of Lactobacillus helveticus Culture on Physical Properties of Mozzarella Cheese

Abstract

Six-liter vats of Mozzarella cheese were made using either single strains of Lactobacillus helveticus or paired strains of L. helveticus and Streptococcus salivarius ssp. thermophilus. Lactobacillus helveticus strains were either strongly or weakly proteolytic as established by the o-phthaldialdehyde test. Three cheeses were made with each culture type and stored at 4°C. Stretch, melt, color, moisture, and pH values were determined at l, 7, 14, and 28 d. All cheeses lost stretch rapidly from d 1 to 7 and slowly declined between d 7 and 28. Melt increased rapidly for all cheeses from d 1 to 7 and then remained constant. Differences in stretch and melt from one culture type to another were not significant. Cheese made with proteinase-deficient strains had more stretch after holding for 14 and 28 d than cheese made with nondeficient strains. Time of storage significantly affected both stretch and melt over 28 d. Cheeses made from all four culture types decreased in cook color over 28 d of storage. There were no significant strain differences in cook color, but the culture by time interaction was significant. Cheese made with pairs or single strains of L. helveticus had the same melt, more strech, and less cook color than cheese made with paired strains of Lactobacillus delbrueckii ssp. bulgaricus and S. salivarius ssp. thermophilus studied previously.