In food industry there are two process mechanical and cryogenic
In mechanical freezing air is passed over food items causing them to slowly cool down and freeze
while in cryogenic or flash freezing ,food items are either directly sprayed or immersed in refrigerates like liquid nitrogen or carbon dioxide thus freezing the food instantly.
Frozen foods do have certain advantages
Firstly nutritional loss is almost negligible
Secondly while transporting and storing fresh food items ,harmful bacteria can grow and contaminate the food , however this will not happen in case of frozen foods because bacteria don’t usually grow in low and freezing temperature ,however some frozen foods may contain stabilizer and trans-fat, which is harmful
Canning Is basically a method in which food and items are processed and then packed into air tight containers. This helps in preserving the food for a longer period
However there are disadvantages of canned food
Firstly: Canned food can be high in sugar and salts so they can be risk for people with high blood pressure, diabetes and obesity e.t.c.
Secondly: Most cans have a coating of “bis-phenol A “ to prevent corrosion ,studies suggest that “bis-phenol A” can leak into the food and have negative affect on our hormones and reproductive system
Thirdly: Acids present in food can react with metal Can and produce hydrogen gas thus making food unsafe to eat.
Lastly: Improper canning process can lead to the growth of dangerous bacteria called clostridium botulinum. It produces a lethal toxin which if consumes can paralyses our muscles and cause death if left untreated.