Question

The process of yoghurt manufacture involves the following sequence
(A). Homogenization of milk
(B). Standardization of milk
(C). Pasteurization, cooling followed by addition of starter culture
(D). Fermentation, packaging and storage
Choose the most appropriate answer from the options given below:

• A. (C), (A), (B), (D)
• B. (B), (C), (A), (D)
• C. (B), (A), (C), (D)
• D. (A), (B), (C), (D)

Hint:

For dairy processing sequences, always start with adjusting the raw material (Standardization). Heat treatment (Pasteurization) comes before adding live cultures, and the biological process (Fermentation) is the core manufacturing step before final packaging.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Yoghurt production is a controlled process that transforms milk into a fermented dairy product. Each step is performed in a specific order to ensure the final product has the desired safety, texture, and flavor.
Step 3: Detailed Explanation:
The standard sequence for yoghurt manufacturing is as follows:
1. (B) Standardization of milk: The process starts with adjusting the milk's composition. This primarily involves modifying the fat and milk solids-not-fat (MSNF) content to meet legal standards and achieve the desired final texture.
2. (A) Homogenization of milk: The standardized milk is then homogenized by forcing it through small orifices under high pressure. This breaks down the fat globules, preventing cream separation and resulting in a smoother, more viscous yoghurt.
3. (C) Pasteurization, cooling followed by addition of starter culture: The milk is pasteurized at a high temperature (e.g., 85-95\(^{\circ}\)C) to kill spoilage and pathogenic bacteria and to denature whey proteins, which helps create a more stable gel. The milk is then cooled to the optimal fermentation temperature (40-45\(^{\circ}\)C) before the starter culture ({Lactobacillus bulgaricus} and {Streptococcus thermophilus}) is added.
4. (D) Fermentation, packaging and storage: The inoculated milk is incubated at the set temperature. During this time, the starter bacteria ferment lactose into lactic acid, causing the milk pH to drop and the casein proteins to coagulate, forming the characteristic yoghurt gel. After the desired acidity is reached, the yoghurt is cooled, packaged, and stored under refrigeration.
Step 4: Final Answer:
The correct chronological sequence of the steps is (B) \(\rightarrow\) (A) \(\rightarrow\) (C) \(\rightarrow\) (D). This matches option (C).