Hydrostatic pressure pulse

Toepfl, S., Mathys, A., Heinz, V., and Knorr, D. (2006). Review Potential of high hydrostatic pressure and pulsed electric fields for energy efficient and environmentally friendly food processing. Food Rev. Int. 22, 405-423. 

Non-thermal processes other than ionizing irradiation are processes such as ultrasound, high hydrostatic pressure (HHP) and pulsed electric fields (PEFs) (Raso and Barbosa-Canovas, 2003 Ross el al., 2003). 

High hydrostatic pressure (HHP) and pulsed electric fields (PEFs) are rather novel technologies where relatively little research has been carried out. These methods have mostly been tested in combination with other decontamination methods and also mostly on either microorganisms in vitro or on foods of animal origin (e.g. milk, eggs and meat) (Raso and Barbosa-Canovas, 2003 Ross et al., 2003). More research is needed in order to find out if such methods are applicable to the fresh produce industry. 

Corrales M, Toepfl S, Butz P, Knorr D and Tauscher B. 2008. Extraction of anthocyanins from grape byproducts assisted by ultrasonics, high hydrostatic pressure or pulsed electric fields a comparison. Innov Food Sci Emerg Technol 9(1) 85-91. 

The momentum of the water as it moves outward causes the gas bubble to over-expand so that its pressure drops below the hydrostatic pressure, and then to collapse as liquid flows back in. The return flow also overshoots the gas pressure rises again, but to nowhere near the detonation pressure. However, the bubble expands again in rebound, behaving in effect as a second explosion. Several successive rebounds may occur, each becoming weaker. To evaluate the total damage, both the shock wave and the subsequent bubble pulses must be considered... 

The recent introduction on the market of a new category of health-promoting functional food has created a need to develop appropriate novel technologies in order to optimise the desired beneficial properties of bioactive ingredients. To this end, novel techniques, such as high hydrostatic pressure, supercritical fluid extraction, microencapsulation and pulsed electric field techniques may provide feasible options in the future (Korhonen, 2002). 

DNA is a large and highly charged molecule with very limited diffusion capacity by itself. Injechon in suspension may add a hydrostatic pressure that can aid the distribution in a tissue. However, there is also an advantage to this situation, which is that DNA also does not readily diffuse out of the injected area easily. Thus it has been shown that pulse delivery even minutes after DNA injection still leads to excellent levels of transgenic expression [16, 17]. 

Corrales, M., Toepfl, S., Butz, P, Knorr, D., and Tauscher, B. 2008a. Extraction of anthocya-nins from grape by-products assisted by ultrasonics, high hydrostatic pressure or pulsed electric fields A comparison. Innovative Food Science and Emerging Technologies 9 85-91. 

Heinz, V. and Knorr, D. 2000. Effect of pH, ethanol addition and high hydrostatic pressure on the inactivation of Bacillus subtilis by pulsed electric fields. Innovative Eood Science and Emerging Technology 1 151-159. 

Raso, J., Calderon, M.L., Gongora-Nieto, M.M., Barbosa-Canovas, G.V., and Swanson, B.G. 1998. Inactivation of Zygosaccharomyces bailii in fruit juices by heat, hydrostatic pressure and pulsed electric fields. Journal of Food Science 63 1042-1044. 

C. C. Y. Poon, Y. T. Zhang and Y. B. Liu, Modeling of pulse transit time under the effects of hydrostatic pressure for cuffless blood pressure measurements, in Proceedings of the 3rd lEEE-EMBS International Summer School and Symposium on Medical Devices and Biosensors, U.S.A., pp, 65-68,2006. 

A radioactive solution containing Co of the total radioactivity of ca. 4000 counts/100 sec was anployed as a radioactive feed. The respective radioactivity counting rate (pulse/sec), treated as the intensity of the y-radiation of a 5 cm liquid sample containing Co, was measured by a y-analyzer, LG-IB (INCT). The obtained values were compared with the radiation intensity of the Co standard sample. Therefore, the specific activity of the feed (Ap), the retentate (Ar), and the permeate (Ap) were calculated. The parameters (/ ), (DF), and if) were determined when the radioactive solutions were treated. In all the experiments, the transman-brane hydrostatic pressure was maintained at 0.22 MPa and the feed flow rate at 401/h. Substantially high DFs for radioactive Co were obtained for the SMM-modified membranes used in the UF/complexation process 223 for SMM3/PES and 163 for SMM41/PES (Table 1.2). For the unmodified membranes, the DFs were lower 44 for the commercial PES membrane and 75 for the prepared unmodified PES membrane. Additionally, the SMM-modified membranes showed smaller adsorption of the radioactive cobalt than the modified membranes, which was beneficial, taking into account the considered applications. After a 2 h operation, the adsorption of Co by the SMM-modified membranes was four to five times smaller than that of the unmodified PES membrane. 

Corrales, M Toepfl, S Butz, P Knorr, D Tauscher, B. Extraction of anthocyanins fi om grape by-products assisted by ultrasonies, high hydrostatic pressure or pulsed electrie fields A comparison. Innovative Food Science Emerging Technologies, v. 9, p. 85-91, 2008. 

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