Question:
The ‘foam theory of churning’ has been put forth by following scientist(s):
The ‘foam theory of churning’ has been put forth by following scientist(s):
Show Hint
N/A
Updated On: Aug 7, 2026
- Rahn
- King
- Fisher and Hooker
- Van Dam and Holwerda
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Step 1: Understanding the Concept:
The churning of cream into butter is a physical process that involves destabilizing the fat emulsion.
Different theories have been proposed to describe the mechanism of this phase transition.
Step 2: Detailed Explanation:
The "foam theory of churning" was proposed by the scientist Otto Rahn in 1922:
1. Role of Air and Foam: Rahn proposed that the incorporation of air and the subsequent formation of foam are necessary for churning.
During churning, rapid agitation incorporates air into the cream, creating a large foam surface area.
2. Concentration of Fat Globules: Fat globules gather at the air-water interface of the foam bubbles.
3. Destabilization of the Membrane: The surface tension forces at the interface, combined with mechanical friction, disrupt the protective milk fat globule membrane (MFGM).
This release of liquid fat allows the globules to adhere to one another and form butter granules.
As the foam collapses, the gathered fat globules aggregate into butter granules, while the aqueous phase is released as buttermilk.
In contrast:
King's theory focuses on the continuous fat phase and partial coalescence mechanisms.
Fischer and Hooker proposed the phase reversal theory, which describes churning as a transition from an oil-in-water to a water-in-oil emulsion without requiring foam formation.
Step 3: Final Answer:
Therefore, the foam theory of churning was proposed by Rahn.
The churning of cream into butter is a physical process that involves destabilizing the fat emulsion.
Different theories have been proposed to describe the mechanism of this phase transition.
Step 2: Detailed Explanation:
The "foam theory of churning" was proposed by the scientist Otto Rahn in 1922:
1. Role of Air and Foam: Rahn proposed that the incorporation of air and the subsequent formation of foam are necessary for churning.
During churning, rapid agitation incorporates air into the cream, creating a large foam surface area.
2. Concentration of Fat Globules: Fat globules gather at the air-water interface of the foam bubbles.
3. Destabilization of the Membrane: The surface tension forces at the interface, combined with mechanical friction, disrupt the protective milk fat globule membrane (MFGM).
This release of liquid fat allows the globules to adhere to one another and form butter granules.
As the foam collapses, the gathered fat globules aggregate into butter granules, while the aqueous phase is released as buttermilk.
In contrast:
King's theory focuses on the continuous fat phase and partial coalescence mechanisms.
Fischer and Hooker proposed the phase reversal theory, which describes churning as a transition from an oil-in-water to a water-in-oil emulsion without requiring foam formation.
Step 3: Final Answer:
Therefore, the foam theory of churning was proposed by Rahn.
Was this answer helpful?
0
0
Top ICAR AIEEA Dairy Technology Questions
- As per legal standards (FSSR, 2011), the acidity (%LA) of chakka should not be more than:
- Which of the following food additive is permitted as preservative in paneer?
- Given below are four statements:
Statement (I) : Homogenisation breaks down fat globules in milk into smaller entities.
Statement (II) : Homogenisation breaks down fat globules and casein micelles in milk into smaller entities.
Statement (III) : Homogenisation slightly increases viscosity of milk.
Statement (IV) : Homogenisation improves the appearance of milk.
In light of the above statements, choose the most appropriate answer from the options given below. - With regard to temperature of operation, place the following unit operations in sequence in an increasing order of temperature:
(i) Sterilisation
(ii) Thermisation
(iii) Homogenisation
(iv) Bactofugation and
(v) HTST pasteurization.
Choose the correct answer from the options given below : - “Narampak” and “karapak” refer to varieties of sandesh with reference to which of the following parameters ?
View More Questions
Top ICAR AIEEA Dairy Product Technology Questions
- Given below are four statements:
Statement (I) : Homogenisation breaks down fat globules in milk into smaller entities.
Statement (II) : Homogenisation breaks down fat globules and casein micelles in milk into smaller entities.
Statement (III) : Homogenisation slightly increases viscosity of milk.
Statement (IV) : Homogenisation improves the appearance of milk.
In light of the above statements, choose the most appropriate answer from the options given below. - “Narampak” and “karapak” refer to varieties of sandesh with reference to which of the following parameters ?
- In sensory evaluation of dairy products, maximum marks are allotted to which of the following attribute ?
- Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : During paneer manufacture, pressing of coagulum in hot condition is essential.
Reason (R) : Pressing in hot condition can fuse the coagulum into a firm single block.
In light of the above statements, choose the correct answer from the options given below. - Match List-I with List-II
\begin{tabular{ll} List-I (Name of the cheese) & List-II (Country of origin)
(A) Limburger & (I) Portugal
(B) Queso-Blanco & (II) Germany
(C) Requeijao & (III) Peru
(D) Ziger & (IV) Belgium
Match the name of the cheese with its country of origin :
View More Questions
Top ICAR AIEEA Questions
- Which of the following statements is false?
- Which of the following is an example of an inventory?
- According to Adam Smith, productivity gains could be brought about through .
- The supply curve for an artificially scarce good is .
- Which of the following would not be considered an opportunity cost of paid employment?
View More Questions