Dairy Engineering

Concept: An egg consists of several structural components, each with specific biological functions. The blastodisk plays a crucial role in embryonic development.
Step 1: Understanding blastodisk.
The blastodisk is a small, circular, whitish spot present on the surface of the yolk. It is the site where fertilization occurs and from which the embryo develops.
Step 2: Location of blastodisk.
It is located on the egg yolk, not in the albumen or shell.
Step 3: Functions of other parts.

• Albumen: Provides water and protein to the embryo
• Egg shell: Protective outer covering
• Chalaza: Holds the yolk in position

Step 4: Conclusion.
Thus, the blastodisk is present in the egg yolk.

Concept: Carbohydrates can be identified using several qualitative chemical tests. Among these, one test is considered a general test applicable to all types of carbohydrates.
Step 1: Understanding Molisch Test.
Molisch Test is a general test used to detect the presence of carbohydrates.
Step 2: Principle of the test.
Carbohydrates, when treated with concentrated sulfuric acid, undergo dehydration to form furfural or hydroxymethylfurfural, which reacts with Molisch reagent (α-naphthol) to produce a violet ring.
Step 3: Observation.
Formation of a purple/violet ring at the junction of two layers indicates the presence of carbohydrates.
Step 4: Eliminating other options.

• Biuret Test: Detects proteins
• Benedict’s Test: Detects reducing sugars only
• Iodine Test: Specific for starch

Step 5: Conclusion.
Thus, Molisch Test is the most widely used general test for identifying carbohydrates.

Concept: Milk is highly susceptible to microbial contamination. To ensure safety and extend shelf life, specific heat treatments are applied to destroy harmful microorganisms without significantly affecting nutritional quality.
Step 1: Understanding Pasteurization.
Pasteurization is a controlled heat treatment process in which milk is heated to a specific temperature for a defined time and then rapidly cooled.
Step 2: Purpose of Pasteurization.

• Destroys pathogenic (disease-causing) microorganisms
• Reduces total microbial load
• Preserves taste and nutritional value

Step 3: Types of Pasteurization.

• LTLT (Low Temperature Long Time): 63°C for 30 minutes
• HTST (High Temperature Short Time): 72°C for 15 seconds

Step 4: Eliminating other options.

• Sterilization: Destroys all microorganisms but affects taste and nutrients
• Homogenization: Breaks fat globules, not related to microbes
• Fermentation: Uses microbes intentionally (e.g., curd)

Step 5: Conclusion.
Thus, pasteurization is the treatment used to remove undesirable microbes from milk.

Concept: In food science, especially in bakery technology, various instruments are used to measure dough properties such as elasticity, extensibility, and plasticity.
Step 1: Understanding dough plasticity.
Plasticity refers to the ability of dough to undergo deformation without breaking, which is crucial for bread-making quality.
Step 2: Role of Extensograph.
The Extensograph measures the extensibility and resistance of dough when stretched, which directly reflects its plasticity and handling properties.
Step 3: Functions of other instruments.

• Farinograph: Measures water absorption and dough mixing properties
• Amylograph: Measures starch gelatinization and enzyme activity
• Viscometer: Measures viscosity of fluids

Step 4: Conclusion.
Thus, the Extensograph is primarily used to determine the plasticity of bread dough.