Step 1: Concept Overview:
The question identifies the specific starter culture required for Mozzarella cheese production. The appropriate culture is determined by the cheese's processing conditions.
Step 2: Detailed Explanation:
Mozzarella is a pasta filata, or stretched-curd, cheese. Its production involves cooking the curd at a high temperature (approximately 40-45°C), followed by heating and stretching in hot water (around 75-85°C) once the pH reaches about 5.2.
This process necessitates thermophilic (heat-loving) cultures that can survive and produce acid at these elevated temperatures.
Analyzing the options:
(A) S. thermophilus and L. delbrueckii subsp. bulgaricus: Both are thermophilic lactic acid bacteria. This combination is commonly used for yogurt and is well-suited for Mozzarella production because of its ability to rapidly generate acid at high temperatures.
(B) This option contains Propionibacterium freudenreichii subsp. shermanii, which is responsible for the characteristic "eyes" (holes) and nutty flavor in Swiss cheese and is unsuitable for Mozzarella.
(C) Leuconostoc mesenteroides subsp. cremoris: This mesophilic (moderate-temperature) culture is known for producing gas (CO\(_2\)) and aroma compounds (diacetyl). It's used in products like buttermilk, but not Mozzarella.
(D) Propionibacterium: As stated above, this culture is for Swiss cheese production.
Step 3: Final Answer:
The correct thermophilic culture combination for Mozzarella cheese is Streptococcus thermophilus and a thermophilic Lactobacillus species, such as Lactobacillus delbrueckii subsp. bulgaricus.