Which of the following processes is not used to preserve the food? - India Site (2024)

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1. Irradiation (A): This process involves exposing food to ionizing radiation to eliminate bacteria, insects, and other pathogens. It disrupts the DNA and cellular structure of microorganisms, preventing them from reproducing. Irradiation has been proven effective in preserving the freshness and safety of certain foods.

2. Addition of salts (B): Salting is a traditional method of food preservation. It works by drawing out moisture from the food, creating an environment where bacteria and fungi cannot thrive. The high concentration of salt acts as a natural preservative, inhibiting the growth of spoilage microorganisms.

3. Addition of heat (C): Heat treatment, such as pasteurization and canning, is a widely used method to preserve food. Pasteurization involves heating food to a specific temperature for a set duration to kill harmful bacteria. Canning involves sealing food in airtight containers and heating to eliminate microorganisms, preventing spoilage.

4. Hydration (D): The correct answer is (D) Hydration. Unlike the other processes mentioned, hydration is not a method used for food preservation. In fact, adding water to food promotes microbial growth and accelerates spoilage, making it counterproductive for preservation.

Moving on to the additional topics mentioned in the article:

• Chromyl chloride test: This test is used to detect the presence of chloride ions. The equation for the reaction involves the formation of chromyl chloride (CrO2Cl2) when a chloride ion reacts with chromate or dichromate ions.

• Lanthanide contraction: This phenomenon refers to the decrease in ionic radii of lanthanide elements as you move across the series. It occurs due to poor shielding of nuclear charge by inner electrons.

• Oxidation properties of potassium permanganate in acidic medium: Potassium permanganate ((KMnO_4)) is a strong oxidizing agent in acidic medium, where it undergoes reduction, changing from a purple color to a colorless solution.

• Double salt vs. complex salt differences: Double salts are compounds formed by the combination of two different salts, while complex salts involve a central metal ion bonded to one or more ligands.

• DNA vs. RNA differences: Differences include the sugar present (deoxyribose in DNA, ribose in RNA), the presence of thymine in DNA and uracil in RNA, and the structure (double-stranded helix in DNA, single-stranded in RNA).

• Tetrahedral geometry: The compound with tetrahedral geometry is (c) (\left[\mathrm{PdCl}_{4}\right]^{2-}) in the given options.

• Oxidation number of gold metal: The correct answer is (b) 0. Gold typically exhibits an oxidation state of 0 in its elemental form.

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