Electron Beam Pasteurization and Complementary Food Processing Technologies. http://dx.doi.org/10.1533/9781782421085.2.127 Copyright © 2015 Elsevier Ltd. All rights reserved. 8 High pressure processing (HPP) of foods and its combination with electron beam processing T. Bolumar, E. Georget, A. Mathys German Institute of Food Technologies (DIL), Quakenbrueck, Germany 8.1 Introduction The irst contact with high pressure processing (HPP) technology in food was in the late nineteenth century. Bert Hite (1899) at West Virginia University Agricultural Experimental Station published the irst detailed report on the use of high pressure as a food preservation method. He reported that milk “keep sweet for longer” after a pressure treatment of around 650 MPa for 10 min at room temperature (Hite, 1899). However, it was not till the 1980s, one century later, that the irst industrial developments in the area of food technology were accomplished. In the 1990s the irst commercial HPP products were produced in Japan (Yaldagard et al., 2008), and following in the twenty-irst century steady growth has been observed in many food sectors worldwide. HPP is currently an alternative to thermal processing, mainly applied in the food industry as a post-packaging pasteurization in order to ensure food safety. HPP provides a gentle pasteurization method, in comparison to conven- tional thermal processing, with minimal effects on sensorial quality and nutritional content. In the present chapter, a comprehensive overview of the thermodynamic aspects under high pressure conditions and the equipment used for HPP application are pre- sented. The chapter then addresses the effect of the application of high pressure on microorganisms and thus the use of HPP as a food preservation method. High pres- sure effects on vegetative and sporulated forms of microorganisms are discussed sep- arately. Next, the chapter describes the use of HPP in relation to the structural changes that HPP treatments induce in food systems, a topic that has been gaining attention from the food industry in more recent years. These structural changes are based on the effect of high pressure on the biopolymers present in the food, and can lead to diverse food applications such as the creation of novel textures, the improvement of the water binding and the mediation of gelation processes. After that, the chapter lists the main commercial applications so far. Beverages, sauces, meat products and sea- food products already beneit for the use of HPP technology, mainly for preservation purposes. Novel and future potential applications of the HPP are highlighted. Finally, the combined use of HPP and electron beam (eBeam) is presented as an alternative of hurdles addition, which may result in optimized food preservation.