The continuous development of food production technologies is essential because of the uninterruptedly growing food production; the transportation of these food products, which means longer and longer transport; and because of the increasing consumer demands concerning the applied technologies, which assure the safe and healthy nutrition. This modernisation trend today has already reached the development of minimally food processing technologies, which make possible the creation of food products preserving their original nutritional values and having a higher added value. Concerning the application of any new technology, it is a more and more important demand that the environmental impact should be lower compared to the earlier technologies. This lower impact can be manifested in less energy and water use, in less wastes production or in more rational energy use.
J. KERRY, J. KERRY and D. LEDWARD (Eds): Meat processing. Improving quality,RC Press, Boca Raton, Boston, New York, Washington, DC, Woodhead Publishing Limited, Cambridge, England, ISBN 1 85573 583 0, 464 pages C. ROBIN (Ed.): Extrusion cooking. (Technologies and applications) CRC Press Boca Raton, 2001, ISBN 0-8493-1207-8; Woodhead Publishing Ltd, 2001, ISBN 1 85573 559 8, 206 pages
Authors:S. Ferenczi, Zs. Cserhalmi, B. Visnyei, V. Szűcs and B. Czukor
Microwave vacuum drying is a novel and mild food preserving technology. Beside its basic preserving function, it can be combined with other technologies, like hot-air drying. As a result of this combination, special snack can be produced from apple. The product is characterized by its unique consistency, high nutritional value, and consumer preference. In this work physical (dry mass content, hardness, bulk density, and colour), sensory (appearance, colour, odour, taste, texture) and nutritional (antioxidant activity and total phenolics) properties of dried apple snack were investigated as a function of pre-drying, microwave energy input, and batch weight. For evaluation of data, central composite experimental design was applied. According to the results, the physical properties of products produced by microwave vacuum drying combined with hot-air pre-drying (CMVD) mainly depend on the specific energy input. Higher specific energy input results higher dry mass content, which is associated with harder consistency, lower bulk density, and positive consumer perception as well. Bulk density had an optimum point of batch weight at 336 g. Higher value of pre-dried dry mass content resulted lighter colour but less antioxidant activity and less total phenolics, therefore shorter hot-air drying and prolonged microwave vacuum drying is recommended.