ADVANCES IN MICROSTRUCTURAL MODIFICATION AND MONITORING OF FOODS DURING DRYING

摘要

A number of changes food undergoes during drying are related,one way or another,to changes in its microstructure.An ability to modify the microstructure of a food material is therefore highly desirable as this would allow us to produce a product with the desired characteristics.Microstructural modification can be achieved in a number of ways,including the use of appropriate thermal and non-thermal processing,with or without sample pretreatment.This paper presents a brief review on how to use selected drying technologies to create various microstructures.The objectives for microstructural modification range from creating a more porous structure to produce highly-crisp fat-free snacks to modifying the microstructure to enhance the release of a compound from the food matrix and hence increased the bioaccessibility and/or extractability of the compound.The use of fractal dimension as a quantitative indicator of the microstructural changes and as a structure-quality indicator relating the changes at the microscopic level to those at the macroscopic level (apparent changes,which are of direct interest to consumers) is also discussed.