Q. How does dehydration work to preserve food
- Provides an acidic environment
- Removes oxygen exposure
- Removes water content
- Removes water content by freezing water particles
Answer: c)
Dehydration, in food processing, means by which many types of food can be preserved for indefinite periods by extracting the moisture, thereby inhibiting the growth of microorganisms. Dehydration is one of the oldest methods of food preservation and was used by prehistoric peoples in sun-drying seeds. The North American Indians preserved meat by sun-drying slices, the Chinese dried eggs, and the Japanese dried fish and rice.
Hot-air dehydration was developed in France in 1795, enabling the commercial production of dehydrated food products, particularly spaghetti and other starch products.
Q. How does freezing work to preserve food
- Provides an acidic environment
- Removes oxygen exposure
- Removes water content
- Removes water content by freezing water particles
Answer: d)
Freezing has been successfully employed for the long-term preservation of many foods, providing a significantly extended shelf life. The process involves lowering the product temperature generally to -18 °C or below (Fennema et al., 1973). The physical state of food material is changed when energy is removed by cooling below freezing temperature. The extreme cold simply retards the growth of microorganisms and slows down the chemical changes that affect quality or cause food to spoil.
Competing with new technologies of minimal processing of foods, industrial freezing is the most satisfactory method for preserving quality during long storage periods.
Q. Which food preservation technique works by providing an acidic environment
- Adding sugar
- Sun drying
- Adding lactic acid
- Pickling
Answer: d)
Preservation techniques to produce lactic acid in sour foods such as sauerkraut, dry sausages, kimchi, and yogurt; and in the pickling of foods with vinegar (acetic acid).
Q. Which of the following are not examples of food preservation techniques
- Adding sugar, dehydrating & pickling
- Freezing, Adding Lactic acid & Dehydrating
- Adding salt, canning and vacuum sealing
- Baking, Frying and boiling
Answer: d)
- Salt can be used to prevent from fungi
- Drying takes away the wetness which won’t allow the bacteria to grow
- Pickling too helps the food to last longer
- But we can’t say that boiling doesn’t help the process because boiling of milk is also a process of prevention but frying and baking don’t prevent.
Q. Preservation of food means
- To keep food safe
- To retain quality of food
- To prevent decomposition of food
- All the above
Answer: c)
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