Convenience and a rise in health awareness has increased the demand for ready-to-eat vegetables and fruits; however, along with this increase in demand has been an increase in the number of food poisonings associated with the low-temperature storage and distribution of foods. To maintain the quality and safety of vegetables, we have conducted basic research on the freezing tolerance of plants by using chlorella and yeast. First, two low-temperature inducible genes from Chlorella were investigated by genetic modification techniques. Next, the availability of taurine and trehalose to plants stored at freezing temperatures was investigated. Finally, a rapid detection method for Listeria monocytogenes, a psychrophilic bacterium and a pathogen in foods stored and transported at low temperature, was developed based on subtyping clinical isolates and isolates from food and the environment.