SFB 564, TP E1.2: Multi-layer drying models for optimization of high value crop drying in small scale food industries

For quality analysis, experiments on the functional interaction between drying conditions (temperature, humidity, air velocity), of relevant index enzymes activities (peroxidase POD, polyphenoloxidase, PPO; lipoxygenase, LOX) and the quality determining criterions (flavour, aroma, texture, colour, vitamin content) will be followed by quality evaluation and optimising the drying conditions. Using adequate simulation programmes, the mathematical modelling of the drying process including the enzyme kinetics and the temporal changes of quality attributes will lead first to simulate the drying process for a single fruit and further on to simulations of stationary high-temperature drying processes as well as solar drying processes at unsteady conditions. The development and validation of the simulation model based on the results of the drying tests including an economical analysis will enable the development and optimisation of a flat bed dryer for unpeeled longans and lychees, the most important fruits in the area of interest. Partly recirculation of the exhaust air is expected to have a significant impact on energy consumption and processing costs.

Funded by the Deutsche Forchungsgemeinschaft (DFG), Germany and co-funded by the National Research Council of Thailand with a sum of 285 000 Euro