Effects of Proteolytic Starter Cultures on Melt Characteristics of Low Moisture Part Skim Mozzarella Cheese

The study assessed the feasibility of using selected starter cultures and different types and levels of coagulating enzyme for making Mozzarella cheese with desired functionality. LMPS Mozzarella cheeses were made from cow\u27s milk standardized to 1.8% fat made with four different types of starter cultures comprising Streptococcus thermophilus (ST), Lactobacillus helveticus (strain SH-Z or L-11), and Lactobacillus delbrueckii ssp. bulgaricus (LB-12). Cheeses were made with ST and combination of ST and SH-Z, ST and L-11 or ST and LB-12. Rennet and Cryphonecteria parasitica (CP) were used at two different levels (lx or 6x) as coagulating enzymes. Cheeses were analyzed for fat, protein, moisture, total solids, calcium, salt, and ash on day 1. Changes in melt characteristics and proteolysis during storage (4°C) were monitored on 1, 7, 15, and 30 days (d). Meltability of cheese as measured by modified Schreiber test showed differences for cheeses made with different types of starter cultures, and also for different types and level of coagulating enzymes. Cheeses made with ST+ SH-Z with coagulant CP at 6x level of enzyme resulted in highest melt area. Softening time and temperature, and melting time and temperature as measured by melt profile analysis were affected by the type of starter culture and storage period. Extent of flow and flow rate were higher for ST+ SH-Z cheeses and it increased further upon 4°C storage of 30 d. Soluble protein as measured by 12% TCA also increased during storage and was highest for cheeses made with ST+ SH-Z with coagulant CP at 6x level of enzyme. As the aging progressed, faster breakdown of intact caseins by CP and proteolytic lactobacilli SH-Z took place resulting in a faster weakening of the protein matrix of the cheese, which in tum translated into favorable changes in functional characteristics, especially meltability. LMPS Mozzarella cheese made with proteolytic culture along with CP at 6x level has a clear advantage to cheese manufacturers and end users to achieve the desired melt properties in cheese