Techniques to detect electroporation in food tissues

Abstract

Recent academic experiments provided many evidences for disintegration of membrane in biological tissues with pulsed electric fields (PEF) having the strength and duration of order of E = 100-1000 V/cm and tPEF = 10 μs-0.1 s, respectively. Commonly, this disintegration is selectively applied to the membranes without significant impact on the cell walls and other constituents of the tissues. The phenomenon of membrane electroporation is intensively studied during the last decades. Many practical efforts were initiated in the field of PEF application to the processing of food tissues (fruits, vegetables, animal tissues). PEF-assistance for selective extraction, pressing, osmotic treatment, freezing, and drying was already tested. The advantages of PEF for the retention of quality, color, texture, aroma, and other positive qualities of fresh foods were demonstrated. Up to date the different techniques to detect electroporation in food tissues were proposed. They evolve analysis of the microscopic structure and changes in electrical, diffusion, textural, and acoustic properties. In this chapter, the examples of estimation of the membrane disintegration index by different techniques are illustrated. The chapter is concise and covers various type of tissues and as well as the benefits and disadvantages of techniques. Practically all techniques to detect electroporation are destructive (invasive), and they can violate independently the structure of the tissues and misrepresent extend of electroporation. Moreover, the applied procedures of measurements are not universal and require careful adaptation for the selected type of food tissue. In each part of the chapter, emphasis is placed on the particular details of application of these techniques, and their advantages and disadvantages are compared in the conclusion part.