The Theoretical Predicting And The Experimental Research Of The Relative Humidity In The MAP Of The Fruits And Vegetables

Nowadays, Modified Atmosphere Packaging (MAP) is a new technology used in preserving the fruits and vegetables. After developing for decades, the MAP and the related theories are worked up to be perfect. However, most of the resent researches focus on how to reduce the losing weight and greenness of the fruits and vegetables by controlling their respiration. In fact, the putridity of the products is another harmful phenomenon in storage. At the same time, plenty of studies show that the putridity of the products is deeply related with the Relative Humidity (RH) in their containers. The purpose of the thesis is finding out the varying rules of the RH, and providing new theoretic basis and datum for both RH control in packaging container and MAP technology.This thesis contains the following main points:1. Analyze the respiration mechanism of mushrooms and tomatoes, measure their respiration velocities and build up corresponding respiration models. Design the MAP experiments under different packaging technology. According to the outcomes of the experiments discuss the affections on respiration speed caused by different packaging technology.2. Based on the law of conservation of energy and related theory, build up the respiration-evaporation models of fruits and vegetables. Combining with the evaporation, osmosis and hygroscopic character of desiccant, set up the RH predicting model in MAP container.3. Build up the relationship between the hygroscopic rate and the time through the experiments. Design the experiments measure varying of the RH in MAP containers under different packaging technology. According to the outcomes of the experiments discuss the affections on varying of the RH in MAP of the tomatoes and mushrooms by different packaging technology. And discuss the reason of the error in the predicting model of the RH.