Raso-Pueyo / Heinz Pulsed Electric Fields Technology for the Food Industry

Fundamentals and Applications
1. Auflage 2010
ISBN: 978-0-387-31122-7
Verlag: Springer US
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 246 Seiten, eBook

Reihe: Food Engineering Series

In an attempt to improve, or replace, existing food processing methods, several novel technologies have been investigated. Some of these emerging technologies have become alternative means of developing new foods or improving the safety and quality of existing ones while reducing energy consumption for the food industry.Among all emerging nonthermal technologies, high intensity pulsed electric fields (PEF) is one of the most appealing due to its short treatment times and reduced heating effects. Its capability to enhance extraction processes and to inactivate microorganisms at temperatures that do not cause any deleterious effect on flavor, color or nutrient value of foods, opens interesting possibilities for the food processing industry. Pulsed Electric Fields Technology for the Food Industry presents the information accumulated on PEF during the last 15 years by experienced microbiologists, biochemists, food technologists, and electrical and food engineers. It offers to anyone interested in this subject a comprehensive knowledge in this field.

Zielgruppe

Research

Autoren/Hrsg.

Raso-Pueyo, Javier

Heinz, Volker

Inhaltsverzeichnis

Pulsed Electric Fields Processing of Foods: An Overview.- Generation and Application of High Intensity Pulsed Electric Fields.- Fundamental Aspects of Microbial Membrane Electroporation.- Effects of Pulsed Electric Fields.- Microbial Inactivation by Pulsed Electric Fields.- Effect of PEF on Enzymes and Food Constituents.- Extraction of Intercellular Components by Pulsed Electric Fields.- Applications and Equipments.- Applications of Pulsed Electric Fields Technology for the Food Industry.- Pulsed Power Systems for Application of Pulsed Electric Fields in the Food Industry.

Leseproben

"CHAPTER 1 PULSED ELECTRIC FIELDS PROCESSING OF FOODS: AN OVERVIEW (p. 3-4)

Gustavo v. Barbosa-Canovas and Bilge Altunakar

1. INTRODUCTION

The ever-increasing trend toward nutritionally qualified foods has challenged food technology to produce fresh-like foods by replacing thermal treatments with alternative methods of preservation. Thermal processing is a major technology that has been commonly used in the food industry to increase shelf life and maintain food safety with low processing costs (Knorr et al., 1994). To qualify as an alternative method, a new technology should have significant impact on quality while at the same time maintain the cost of technology within feasibility limits. In recent years, several technologies have been investigated that have the capability of inactivating microorganisms at lower temperatures than typically used in conventional heat treatments (Lado and Yousef, 2002).

Therefore, nonthermal methods correspond to the expectations for minimally processed foods of fresh quality, which have higher nutritional value because of color and flavor retention. Among all emerging nonthermal technologies, high intensity pulsed electric fields (PEF) is one of the most appealing technologies due to its short treatment times and reduced heating effects with respect to other technologies. High intensity pulse electric fields is highly appreciated as a nonthermal food preservation technology that involves the discharge of high voltage electric short pulses through the food product.

With the use of electric fields, PEF technology enables inactivation of vegetative cells of bacteria and yeasts in various foods. As bacterial spores are resistant to pulsed electric fields, applications of this technology mainly focus on food-borne pathogens and spoilage microorganisms, especially for acidic food products. In addition to the volumetric effect of PEF technology in controlling the microbiological safety of foods in a fast and homogenous manner, successful application provides extended shelf life without the use of heat to preserve the sensory and nutritional value of foods. PEF technology has the potential to economically and efficiently improve energy usage, besides the advantage of providing microbiologically safe and minimally processed foods.

Successful application of PEF technology suggests an alternative substitute for conventional thermal processing of liquid food products such as fruit juices, milk, and liquid egg (Mertens and Knorr, 1992; Bendicho et al., 2002a; Hodgins et al., 2002). This chapter gives an overview of the basics of pulsed electric field processing of foods within the food industry. Evolution of technology and certain factors involved are summarized with emphasis on a general review of PEF technology.

1.1. Historical Evolution and Chronological Developments in Pulsed ElectricField Processing

There are several ways to use an electrical source for food pasteurization, in the form of ohmic heating, microwave heating, and high intensity pulsed electric fields (HIPEF). Among these, ohmic heating is one of the earliest methods. Ohmic heating relies on the use of heat generated when an electric current passes through the food, and has already been approved for viscous and particulate products, especially for aseptic processing. Application of electric fields to preserve foods first appeared with the Electro-pure method for pasteurization of milk. In this early process, heat generated by an alternating electrical current (220-4200 V) was used as a method of thermal sterilization in which heat flowed through the milk."