M0043: Use of Magnetic Resonance Imaging (MRI) and Low Resolution NMR Relaxometry to Follow Physicochemical Changes in Foods, Detect Quality and Asses Stability of Colloidal Systems
Drying of foods is an ancient practice that has been adopted to preserve foods beyond their natural shelf life. Among the numerous methods used for food conservation, drying is unquestionably the most ancient but still very much used nowadays. The process started with the exposure of foods to the sun, to extract from them a great proportion of the water, thus contributing for their conservation. The traditional solar dying with direct exposure to the sun had many disadvantages and presently more modern methods are used, such as hot air drying, spray drying, lyophilization, infrared, microwave or radiofrequency drying, osmotic dehydration or many combined processes. In drying water is removed from the food, thus reducing its availability for degradation reactions of chemical, enzymatic or microbial nature. The main objectives of drying include to preserve foods and increase their shelf life; avoid the need for use of refrigeration systems for transport and storage (expensive) reduce space requirements for storage and transport; diversify the supply of foods with different flavours and textures, thus offering the consumers a great choice when buying foods. Many foods can be preserved through drying, but their organoleptic and nutritional properties are greatly altered as compared to the fresh counterparts. Thus, during drying it is of interest to minimize chemical changes, such as enzymatic and non enzymatic browning, and to maximize nutrient retention, such as macronutrients (proteins, sugars, fibres, micronutrients (vitamins, minerals, or bioactive compounds (phenolic compounds, carotenoids, isoflavones, One effect frequently observed when drying foods is shrinkage, which considerably affects their structure and texture. This work describes the most relevant drying methods and advances in drying technology and the effects of this operation on the attributes of the dried foods, including physical characteristics, chemical components and nutritional value or sensory properties like aroma, texture and colour. 2017 BUDAPEST CONFERENCE 9 Keynote Speaker II