Question:
Sweetened condensed milk contaminated with rennin like enzyme producing bacterial strain may cause:
Sweetened condensed milk contaminated with rennin like enzyme producing bacterial strain may cause:
Show Hint
Bacterial thickening in sweetened condensed milk is caused by enzymatic proteolysis of casein, which destabilizes the protein micelles and leads to gelation. This is distinct from chemical age thickening, which is driven by physicochemical protein interactions.
Updated On: Jul 23, 2026
- Bloating
- Mould buttons
- Bacterial thickening
- Sugar separation
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Understanding the Concept:
Sweetened condensed milk can undergo a defect known as age thickening during storage, which is characterized by a gradual increase in viscosity that can progress to gelation.
This thickening can be driven by chemical changes or biological contamination.
Step 2: Detailed Explanation:
Let us analyze the biological causes of age thickening in sweetened condensed milk:
- When the product is contaminated with certain bacterial strains (such as some spore-forming Bacillus species) that produce heat-stable extracellular proteases or rennin-like enzymes, enzymatic deterioration can occur.
- Despite the high osmotic pressure, these active enzymes slowly hydrolyze and destabilize the casein micelles.
- This enzymatic cleavage causes the proteins to aggregate and form a continuous gel network, leading to a defect known as "bacterial thickening."
- Let us review the other options:
- Bloating is caused by gas-producing yeasts (such as Torulopsis spp.).
- Mould buttons are caused by the surface growth of molds (such as Aspergillus spp.).
- Sugar separation is a physical defect caused by gravity sedimentation of large lactose crystals.
Therefore, contamination with rennin-like enzyme-producing bacteria leads to bacterial thickening.
Step 3: Final Answer:
Contamination with rennin-like enzyme-producing bacteria causes bacterial thickening. Hence, the correct option is (C).
Sweetened condensed milk can undergo a defect known as age thickening during storage, which is characterized by a gradual increase in viscosity that can progress to gelation.
This thickening can be driven by chemical changes or biological contamination.
Step 2: Detailed Explanation:
Let us analyze the biological causes of age thickening in sweetened condensed milk:
- When the product is contaminated with certain bacterial strains (such as some spore-forming Bacillus species) that produce heat-stable extracellular proteases or rennin-like enzymes, enzymatic deterioration can occur.
- Despite the high osmotic pressure, these active enzymes slowly hydrolyze and destabilize the casein micelles.
- This enzymatic cleavage causes the proteins to aggregate and form a continuous gel network, leading to a defect known as "bacterial thickening."
- Let us review the other options:
- Bloating is caused by gas-producing yeasts (such as Torulopsis spp.).
- Mould buttons are caused by the surface growth of molds (such as Aspergillus spp.).
- Sugar separation is a physical defect caused by gravity sedimentation of large lactose crystals.
Therefore, contamination with rennin-like enzyme-producing bacteria leads to bacterial thickening.
Step 3: Final Answer:
Contamination with rennin-like enzyme-producing bacteria causes bacterial thickening. Hence, the correct option is (C).
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 Introduction to Dairy Microbiology Questions
- Given below are the characteristics of Breribacterium linens, a secondary flora of cheese.
(A) Gram +ve, mesophilic organism, rod-shaped colonies
(B) Produces a yellow orange carotenoid pigment that colours the surface of cheese, colour production is enhanced by exposure to light.
(C) It grows best at neutral pH, use lactose or citrate, grows well at high salt concentration.
(D) Highly proteolytic, degrade whey protein and casein, contribute to flavour production in surface ripened cheese by producing metabolites.
Choose the correct options associated with the given bacteria : - Given below are two statements pertaining to bacteria used in cheese making.
Statement (I) : Propionibacteria species are Gram +ve rods that cause eye by lactate metabolism in Swiss type of cheese.
Statement (II) : Leuconostoc mesemteroids subsp. cremoris is Gm +ve cocci produce eye in Gouda and Edam cheese by lactate metabolism.
In light of the above statements, choose the most appropriate answer from the options given below. - Match List-I with List-II
\begin{tabular{ll} List-I (Microorganism) & List-II (Butter defect)
(A) Achromobacter putrefaciens & (I) Rancid flavour
(B) Pseudomonas ichthyosmia & (II) Putrefactive taint
(C) Pseudomonas nigrificans & (III) Fishy flavour
(D) Achromobacter lipolyticum & (IV) Black discolouration
Choose the correct answer from the options given below : - Ricotta is a soft, unripened variety of whey cheese. Ricotta cheese may be considered as a protein co-precipitate having low shelf-life. Probiotic Ricotta cheese was prepared by incorporation of probiotic organism in Ricotta cheese. Ricotta cheese is a good carrier medium of probiotic organism because of high moisture, high pH, low salt and oxygen.
Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): It was observed during the study that survival of probiotic organism in Ricotta cheese matrix is higher as compared to MRS medium during experimental digestion process.
Reason (R): Higher salt content of cheese might be helpful to provide better protection to organism during harsh digestive condition.
In light of the above statements, choose the correct answer from the options given below. - The following statements are describing the production of vitamins through from fermentation of whey. Choose the correct answer from the options given below:
(A) Vitamin B12 production by Propionibacterium shermanii can be done by using several substrates including cheese whey
(B) This organism (P. shermanii) grows aerobically and produces propionic acid, which accumulates in the medium.
(C) Most industrial processes for the production of vitamin B12 by P. shermanii require neutralization of the accumulated propionic acid to keep the culture growing logarithmically.
(D) The formation of vitamin take place during the later part of the fermentation after the organism approaches maximum growth.
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