Rapid detection and control of psychrotrophic microorganisms in cold storage foods: A review

Background: Psychrotrophic microorganisms reproduce rapidly, producing some high thermal stability lipases and proteases in refrigerated foods, which have negative effects on food quality. There are many researches on the detection of psychrotrophic microorganisms in foods, especially on the development of rapid and automatic technologies. Scope and approach: The present review focuses on the development of rapid detection methods of psychrotrophic microorganisms in cold storage foods, including direct epi-fluorescent filter technique, flow cytometry method, real-time polymerase chain reaction, fluorescence in situ hybridization, temporal temperature gradient gel electrophoresis, and loop-mediated isothermal amplification. Furthermore, the advantages and disadvantages of the methods and applications are compared, and methods for controlling the multiplication of psychrotrophic microorganisms are also discussed. Key findings and conclusions: For better control of psychrotrophic bacteria, a significant number of studies have been performed by employing different detection methods such as polymerase chain reaction, fluorescence in situ hybridization, quartz crystal microbalance, etc., and most of the detection techniques are based on combination of immunoassay and electronic sensors. Although these rapid detection technologies show some obvious advantages, there still exist great challenges in achieving high accuracy and sensitivity. More rapid and convenient detection methods such as microscopic hyperspectral imaging should thus be developed for realizing online microbial detection in the food industry in future.