Application of pef on orange juice products

Among nonthermal technologies, the application of pulsed electric fields (PEFs) is considered a very promising alternative to pasteurization processes for some liquid foods. One example would be fruit juices. The studies carried out so far have shown adequate inactivation levels after very short treatment periods at low temperatures for a number of spoilage and pathogenic microorganisms, molds, and yeasts that can survive in juices, such as Saccharomyces cerevisiae (Grahl et al., 1992; Grahl and Märkl, 1996; McDonald et al., 2000; Jagus et al., 2001; Molinari et al., 2002), Escherichia coli (McDonald et al. 2000; Rodrigo et al., 2003), and Lactobacillus plantarum (Rodrigo et al., 2000). Moreover, studies suggest that PEF has a minimal effect on the quality and nutritive value of fruit juice (Zhang et al., 1996; Qiu et al., 1998; Jia et al., 1999; Yeom et al., 2000a, b; Ayhan et al., 2001a; Min et al., 2002a, b). On the other hand, PEF seems to be less effective on the inactivation of some fruit juice enzymes, such as pectin methyl esterase (PME) or poliphenoloxidase (Zhang et al., 1996; Giner et al., 2001; Yeom et al., 2000a, b, 2002; Rodrigo et al., 2001; Min et al., 2002a, b). With the aid of this technology, these factors all suggest that it may be possible to obtain microbiologically safe juices of high quality with adequate shelf life under refrigerated conditions.