Hanna Kowalska's scientific research is oriented towards the influence of osmotic dehydration parameters on the process kinetics and properties of fruit and vegetables. She is especially interested in mass transfer in and the physical properties of dried and osmotically dehydrated food products and different drying methods. She has been working on lightly processed fruit and vegetables for many years. Some of her studies concerned the osmotic dehydration of fruit and vegetables and the impregnation of fruit and vegetables with vitamins or minerals at a low temperature. The purpose of these studies was to obtain food of high quality and safety with health benefits for consumers.