Melt and Rheological Characteristics of Low Moisture Part Skim Mozzarella Cheese as Affected by the Starter Culture and Coagulating Enzymes

<p>Mozzarella cheeses were made from cows' milk standardized to 1.6% fat. There were two different types of starter cultures comprising only Streptococcus thermophilus. (SC) or a combination of Streptococcus thermophilus and Lactobaci/lus helveticus (MC). Rennet or Cryphonectria parasitica protease at two different levels (1 X and 6X) were used as the coagulating enzymes. MC cheeses had higher moisture and protein contents and lower fat content. Cheeses made with rennet showed a greater hydrolysis of α_S- casein, whereas, cheeses made with sure curd showed a greater hydrolysis of β-casein. The extent of hydrolysis was found to be greater in MC cheeses at 6X level of coagulating enzyme. Maximum hydrolysis of α_S- casein was ~70% in case of MC cheeses made with 6X rennet, but that of β-casein was -50% for MC cheeses made with 6X sure curd. Meltability of cheese as measured by modified Schreiber test showed significant differences for cheeses made with different type of cultures, and also for different types and level of coagulating enzymes. However, when the meltability was measured by Creep test, it was found that the differences were not significant between the types of coagulating enzyme. This indicated that, even if the cheeses soften to a similar extent, their flowability could be different. Meltability as measured by the Schreiber test was correlated best to the hydrolysis of β-casein, which was comparable with soluble nitrogen, but correlated least to α_S -casein. Values of elastic modulus (G') and viscous modulus (G") decreased with the age of the cheese and the decrease was higher in MC cheeses compared to SC cheeses. MC cheeses had higher counts for both lactobacilli and streptococci. Higher number of starter bacteria in MC cheeses might also have contributed to their better meltability through bacterial channel similar to the fat-serum channels.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - University Access Only

Discipline thesis:degree_discipline

Dairy Science

Year dc:date.available

2001

Author dc:creator

• Sharma, Pragati

Contributors dc:contributor

• Rajiv I. Dave

• Dairy Science

Statement dc:rights

• <p>In Copyright - Non-Commercial Use Permitted<br /><a href="http://rightsstatements.org/vocab/InC-NC/1.0/">http://rightsstatements.org/vocab/InC-NC/1.0/</a></p>

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/1504

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-2514