Gas used to manufacture vanaspati from vegetable oil: Hydrogen

Explanation:
Vanaspati is a form of hydrogenated vegetable oil that is solid at room temperature. It is commonly used as a substitute for ghee (clarified butter) in cooking. The process of manufacturing vanaspati involves the use of hydrogen gas.

Process of manufacturing vanaspati:
1. Hydrogenation: The first step in manufacturing vanaspati is the hydrogenation of vegetable oil. This process involves the addition of hydrogen gas to vegetable oil under specific conditions of temperature and pressure.

2. Catalyst: The hydrogenation process is catalyzed by the presence of a catalyst, such as nickel or palladium. The catalyst helps in the breaking of double bonds present in the unsaturated fatty acids of vegetable oil and facilitates the addition of hydrogen atoms.

3. Saturation of fatty acids: During hydrogenation, the unsaturated fatty acids present in vegetable oil are saturated with hydrogen atoms. This process converts liquid vegetable oil into a solid form, which is characteristic of vanaspati.

4. Trans fatty acids: In the process of hydrogenation, some of the unsaturated fatty acids undergo a partial rearrangement, resulting in the formation of trans fatty acids. Trans fatty acids are known to have adverse health effects and are considered unhealthy when consumed in excessive amounts.

5. Deodorization and refining: After the hydrogenation process, the vanaspati undergoes further refining steps, including deodorization to remove any undesirable odors and impurities. This refining process helps in enhancing the quality and shelf life of vanaspati.

6. Addition of flavor and color: Finally, flavoring agents and food-grade colors may be added to the refined vanaspati to enhance its taste and appearance.

Conclusion:
Hydrogen gas is used in the manufacturing process of vanaspati from vegetable oil. The hydrogenation process involves saturating the unsaturated fatty acids in vegetable oil with hydrogen atoms, resulting in the solid form of vanaspati.