25 Nov 2013
Deep-fat frying is one of the oldest and most popular cooking methods, which provides unique textures and flavours that improve overall food palatability. The frying process, normally carried out at 150° - 180°C, is a complex operation due to the combination of heat and mass transfer between the food and the frying medium, illustrated in the figure below.
The system becomes more complicated as the frying operation goes on, because the composition of the food being fried and the frying medium is changing continuously due to the progressive deterioration of the frying oil. Apart from a variety of chemical reactions (such as oxidative, hydrolytic and polymerisation) occurring in the oil, several other changes also take place in the frying food, such as gelatinisation of starch, denaturation of protein, and a decrease of moisture. These changes bring about a swelling of the product, formation of a crusty layer, appearance of golden colour, good texture and taste.
During the last two decades, frying and fried foods have come under fire because of the types of oils used and their possible contribution to health problems and obesity. The industry has responded to these concerns by researching healthier oils, and manufacturing products lower in fat content. The production of low fat and better quality items are achieved by good oil management and selecting correct frying equipment for the application.
Tastier snack products containing low in saturated, high in monounsaturated and practically zero in trans fatty acids have appeared in the shops in recent years. As fried food products will always exist, new developments in frying process techniques and frying equipment design will continue to satisfy the ever changing demand of today's food consumers.
The advancement of new and different frying techniques, including vacuum frying and ultra-fine control systems, will result in producing high value, improved nutritional profile and functional fried food products. The future of frying, pre-fried foods, and fried snacks looks healthy and bright.
The Deep Fat Frying international conference organised by the Lipids Group, and to be held on 5 - 6 June 2014 in Reading will provide insight into developments in frying to produce high quality and healthier products to meet the needs of consumers.
Dr Parkash Kochhar
- Lipids Group
- Developments in Deep Fat Frying for Health and Quality - 5 - 6 June 2014