Question:
Mold button formation in sweetened condensed milk is caused by
Mold button formation in sweetened condensed milk is caused by
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To prevent mold button defects in condensed milk:
- Maintain a high vacuum during canning to remove all oxygen from the headspace.
- Ensure strict plant hygiene and use HEPA filters to prevent mold spores from contaminating the canning area.
- Maintain a high vacuum during canning to remove all oxygen from the headspace.
- Ensure strict plant hygiene and use HEPA filters to prevent mold spores from contaminating the canning area.
Updated On: Jul 23, 2026
- Aspergillus repens
- Proteus vulgaris
- Thermobacterium mathiacelle
- Torulopsis globosa
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The Correct Option is A
Solution and Explanation
Step 1: Understanding the Concept:
Sweetened condensed milk is preserved by adding sucrose to create high osmotic pressure, which inhibits the growth of most vegetative microorganisms.
However, certain highly specialized osmophilic and xerophilic fungi can survive and grow in these low-water-activity environments if oxygen is present.
Step 2: Detailed Explanation:
The "button" defect in sweetened condensed milk is a well-known form of mold spoilage:
- Physical Appearance:
Buttons appear as firm, colored, button-like masses of mold mycelium floating on the surface of the milk inside the can.
They can range in color from light brown to reddish-brown or yellow.
- Causative Agent:
This defect is primarily caused by Aspergillus repens (also classified as Eurotium repens), a xerophilic mold that can tolerate high sugar concentrations.
- Mechanism of Formation:
If oxygen is left in the headspace of the can due to insufficient vacuum sealing, any mold spores present on the surface will germinate.
The mold grows slowly using this limited oxygen supply, utilizing the sucrose and milk nutrients.
It secretes proteolytic enzymes that hydrolyze casein, causing localized protein coagulation that forms a firm, cohesive button-like disk.
Once the oxygen is completely consumed, the mold dies, but the stable button remains on the surface.
Step 3: Final Answer:
The formation of mold buttons on sweetened condensed milk is caused by Aspergillus repens.
Sweetened condensed milk is preserved by adding sucrose to create high osmotic pressure, which inhibits the growth of most vegetative microorganisms.
However, certain highly specialized osmophilic and xerophilic fungi can survive and grow in these low-water-activity environments if oxygen is present.
Step 2: Detailed Explanation:
The "button" defect in sweetened condensed milk is a well-known form of mold spoilage:
- Physical Appearance:
Buttons appear as firm, colored, button-like masses of mold mycelium floating on the surface of the milk inside the can.
They can range in color from light brown to reddish-brown or yellow.
- Causative Agent:
This defect is primarily caused by Aspergillus repens (also classified as Eurotium repens), a xerophilic mold that can tolerate high sugar concentrations.
- Mechanism of Formation:
If oxygen is left in the headspace of the can due to insufficient vacuum sealing, any mold spores present on the surface will germinate.
The mold grows slowly using this limited oxygen supply, utilizing the sucrose and milk nutrients.
It secretes proteolytic enzymes that hydrolyze casein, causing localized protein coagulation that forms a firm, cohesive button-like disk.
Once the oxygen is completely consumed, the mold dies, but the stable button remains on the surface.
Step 3: Final Answer:
The formation of mold buttons on sweetened condensed milk is caused by Aspergillus repens.
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