Vacuum Frying Technology For Healthier Fried Foods Production

Fresh fruits and vegetables are highly perishable, shelf life is so short.

- K. Shunmugapriya, T. R. Thirumuruga Ponbhagavathi and T. Aruna

If not handled properly, fruits and vegetables that have been harvested will undergo physiological, physical, chemical, and microbiological changes that become damaged or rotten. Meanwhile, the tubers usually have a longer shelf life, although some will soon rot in storage, such as cassava. One effort to maintain quality and shelf life of fruit and have a pretty good market is processed into chips. Chips are more durable than the stored fresh fruits or vegetables (incl. tubers) because of the low water contents. Deep-fat (ordinary, atmospheric) frying is one of the oldest food preparation processes and is widely used in the food industry. Frying temperature can range from 130-190°C, but the most common temperatures are 170-190°C. The high temperature of the frying fat typically leads to the appreciated surface color and mechanical characteristics of fried foods; and besides that, heating the reducing sugar affects a complex group of reactions, called mailard reaction and producing acrylamide compound which is genotoxic.

Vacuum frying is a promising technology that could be an option for the production of novel snacks such as fruit and vegetable crisps that present the desired quality attributes and respond to new health trends. The operating pressure used is usually lower than 7 kPa which produces a good reduction in the boiling point of water and allows the frying temperature to be lower than 90oC. Some of the vacuum fried fruits and vegetables are apple, apricot, banana, jackfruit, green and gold kiwifruits, carrot, mushroom, potato, shallot, sweet potato and purple yam.

Types of frying

Fried products can be processed at atmospheric, high, and low (vacuum) pressures.