Question

Which among the following cannot control oxidative rancidity in whole milk powder?

• A. Addition of tocopherol
• B. Flushing of inert gas
• C. Vacuum packaging
• D. Addition of sodium alginate

Hint:

Stabilizers like sodium alginate are used for texture and viscosity modification in liquid dairy products, whereas antioxidants and inert gas packaging are required to prevent lipid autoxidation in dry dairy powders.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Oxidative rancidity is a major degradation pathway of lipids in fat-rich dairy powders during storage.
It involves the autoxidation of unsaturated fatty acids in the presence of oxygen, leading to the formation of hydroperoxides and subsequent volatile off-flavor compounds.
Controlling this process requires removing oxygen, utilizing barrier packaging, or adding antioxidants to scavenge free radicals.

Step 2: Detailed Explanation:
To prevent oxidative rancidity in whole milk powder, several industrial strategies are routinely implemented:
Addition of tocopherol: Tocopherols are natural, fat-soluble antioxidants that act as free radical scavengers.
They readily donate hydrogen atoms to lipid peroxyl radicals, terminating the autoxidative chain reaction.
Flushing of inert gas: Replacing oxygen in the package headspace with nitrogen or carbon dioxide reduces the oxygen concentration below the threshold required for oxidation.
Vacuum packaging: Physically evacuating air from the packaging container removes the primary reactant, oxygen, thereby limiting chemical oxidation.
Addition of sodium alginate: Sodium alginate is a hydrophilic polysaccharide extracted from brown seaweed.
It functions primarily as a stabilizer, thickener, and gelling agent to control viscosity and water-binding capacity in liquid systems.
Because sodium alginate has no antioxidant properties and does not act as an oxygen barrier in dry powders, it cannot control lipid oxidation in whole milk powder.

Step 3: Final Answer:
Therefore, the addition of sodium alginate cannot control oxidative rancidity in whole milk powder.