The first part of the project was aimed at investigating the effects of selected pretreatment methods, i.e., soaking in citric acid, blanching in water as well as in citric acid, on the sample structure and subsequent microwave-assisted extraction (MAE); carrots and -carotene (as well as carotenoids) were selected as the test material and bioactive compound, respectively. At the optimized condition the contents of -carotene and total carotenoids extractable from carrots blanched in water and in citric acid were significantly higher than those from the untreated carrots. The antioxidant activity of the extracts obtained from carrots blanched in water and in citric acid was also higher than that from carrots with no pretreatment. The effects of various parameters, i.e., type of solvent, set microwave power and extraction time, on the extraction yield of sulforaphane, which is a naturally potent anticarcinogenic compound, from cabbage residues were also investigated in the second part of the project. The effect of partial drying prior to MAE on the extractable amount of sulforaphane was as well investigated. No significant differences in the highest extractable sulforaphane contents from the fresh and semi-dried samples were noted. Use of different solvents did not lead to any significant effect on the MAE of sulforaphane, either from the fresh or semi-dried sample. Use of intermittent microwave radiation to allow extended MAE without causing excessive thermal degradation of the interested bioactive compounds was investigated in the third part of the project. Use of appropriate intermittency ratio along with optimum microwave power and solvent-to-sample ratio resulted in larger amounts of extractable β-carotene and total carotenoids as compared with the use of the corresponding continuous MAE. Prolonging the off period and subsequently turning on the microwave radiation resulted in higher antioxidant activity of the extracts in almost all cases. Finally, a mathematical model that can be used to describe the evolutions of temperature and concentration of an extract during both continuous and intermittent MAE was developed. The model consists of the Maxwell’s, energy and species balance equations, along with appropriate initial and boundary conditions. Validation of the model was performed by comparing the simulated results with the experimental temperature and -carotene concentration evolutions of the extracts from carrot peels. In general, the model was capable of predicting the evolutions of the temperature and -carotene concentration quite adequately. In some cases, however, the temperature prediction was compromised due to the evaporation of solvent, which was not considered in the model. The empirical constants of the model were noted to depend on the specific absorbed microwave power and the sample-to-solvent ratio.