APPLICATIONS OF PULSED ELECTRIC FIELD STEFFIN CHEKOT 1721110030
Introduction Many applications of PEF have been investigated in food within the last decades, utilizing its impact on biological cell membranes. Electropermeabilization and cell disintegration, plays a major role in food processing operations. Due to high intensity treatment, inactivation of microbes can be achieved.
Juice Processing Applying PEF to cellular tissue an increase in mass transfer coefficients due to cell membrane permeabilization. There is 10-12% increase of juice yield when applying electroplasmolysis to apple tissue. Application of PEF for juice processing provides a potential to replace or enhance conventional cell disintegration techniques.
PEF TREATMENT OF MICROALGAE, SEAWEED, AND OTHER AQUATIC SPECIES Different varieties of macro- and microalgae are sources of vitamins, pigments, proteins as well as antixodative and bioactive substances. Algae extracts applying PEF treatment could provide a potential toward a gentler downstream processing. There is an increasing in the yield after PEF treatment, mainly in the case of extractablity of growth hormones.
Plant Oil Extraction Sitzmann and Munch (1988) reported an enhanced separation of tankage emulsions when extracting protein and fat from animal tissue. A similar effect can be expected after PEF treatment of oil seeds prior to recovery. Yield and quality of oils has been studied and high oil yield was developed. Oil recovery from olives was improved by 7.4% after a PEF treatment at 1.3 kV/cm in comparison to the control sample. In soybean oil an increase in iso-flavonoid content was reported.
Meat & Fish Treatment Disintegration of animal cellular tissue is used to enhance the curing of fish or meat products. In case of raw ham a long-term curing and air drying is applied. During such procedures a PEF treatment can be applied to improve mass transfer processes and to accelerate curing, reducing the time requirements. An increase in mass transfer rates, resulting in faster water transport to the product surface and therefore drying time can be reduced. This will lead to drastic saving of energy and better utilization of production capacities during convective air drying.
Sugar Processing In Conventional procedures for production of sugar from beets, disintegration and destruction of cell membranes a thermal treatment at temperatures in the range from 70 to 78°C is applied. The membrane de-naturation results in an acceleration of sugar release into the extraction media, but also cell wall components such as pectin may become soluble and can diminish juice purity and quality. A PEF treatment of sugar beets could increase mass transfer rates and could allow to reduce extraction temperatures and better quality of sugar can be obtained.
MICROBIAL DECONTAMINATION The applicability of PEF for microbial inactivation of liquid food has been proven by a high number of studies investigating the impact of PEF on vegetative organisms in model as well as real food material.