Question:
Surface ropiness in milk is caused by:
Surface ropiness in milk is caused by:
Show Hint
Surface ropiness is often a result of contaminated cooling water or poorly sanitized equipment on the dairy farm. It is usually inhibited by acid production.
Updated On: Jul 4, 2026
- Escherichia coli
- Klebsiella oxytoca
- Streptococcus lactis
- Alcaligenes viscolactis
Show Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Concept:
Ropiness is a common defect in milk characterized by an increase in viscosity and the formation of slimy threads.
• It is caused by the synthesis of extracellular polysaccharides (gums).
• These gums are produced by specific bacteria as capsules or slime layers.
Step 1: Identifying the specific causative agent.
Alcaligenes viscolactis is the most common cause of surface ropiness. It is an aerobic bacterium, which explains why the ropiness appears at the surface.
Step 2: Understanding the mechanism.
The bacteria utilize the nutrients in milk to produce a viscous capsular material. When a spoon is lifted from the milk, long "ropes" or threads of slime are pulled up.
Step 3: Comparing other organisms.
Streptococcus lactis is primarily involved in the normal souring of milk. E. coli can cause "stormy fermentation" but not typically surface ropiness. Final Answer: (D)
• It is caused by the synthesis of extracellular polysaccharides (gums).
• These gums are produced by specific bacteria as capsules or slime layers.
Step 1: Identifying the specific causative agent.
Alcaligenes viscolactis is the most common cause of surface ropiness. It is an aerobic bacterium, which explains why the ropiness appears at the surface.
Step 2: Understanding the mechanism.
The bacteria utilize the nutrients in milk to produce a viscous capsular material. When a spoon is lifted from the milk, long "ropes" or threads of slime are pulled up.
Step 3: Comparing other organisms.
Streptococcus lactis is primarily involved in the normal souring of milk. E. coli can cause "stormy fermentation" but not typically surface ropiness. Final Answer: (D)
Was this answer helpful?
0
0
Top TS PGECET Food Technology Questions
- Which of the following is the primary product of photosynthesis?
- A complex group of reactions is
- What is the generic name of glycans?
- Which of the following is an extract from red algae?
- .......... serve as a fuel molecule in foods
View More Questions
Top TS PGECET Food Microbiology Questions
- Cell arrangement of microorganisms fall in
- The logarithmic order of death for bacterial population is described by
- The bacteria that grows in both aerobic and anaerobic conditions is termed as
- The minimum and maximum temperatures required for the shigella species to grow is
- Vinegar is produced by alcoholic fermentation followed by acetic fermentation with
View More Questions
Top TS PGECET Questions
- If \( P = \begin{pmatrix} 1 & 1 & 1 \\ 0 & 1 & 2 \\ 0 & 0 & 1 \end{pmatrix} \) is the modal matrix of \( A = \begin{pmatrix} 1 & 1 & 0 \\ 0 & 2 & 2 \\ 0 & 0 & 3 \end{pmatrix} \) then the sum of all the elements of \( P^{-1}AP \) is
- If the system of equations \( kx + y + z = k - 1 \), \( x + ky + z = k - 1 \), and \( x + y + kz = k - 1 \) has infinite solutions, then \( k \) is
- The value of the integral \( \int_C (2xy - x^2) \, dx + (x^2 + y^2) \, dy \) where \( C \) is the boundary of the region enclosed by \( y = x^2 \) and \( y^2 = x \), described in the positive sense, is
- Let \( f(x) = \log x \). The number \( C \) strictly between \( e^2 \) and \( e^3 \) such that its reciprocal is equal to \( \frac{f(e^3) - f(e^2)}{e^3 - e^2} \) is
- The solution of the differential equation \( (D^2 + 2)y = x^2 \) is
View More Questions