Advances in Use of High Pressure to Processing and Preservation of Plant Foods

Abstract

Fruitand vegetable-derived products are traditionally produced with conventional technologies such as thermal processing, which inhibits microbial spoilage and reduces enzymatic activities. Although thermal processing ensures the safety and shelf life of food, it can dramatically affect quality factors, especially the food’s aroma, vitamin content, and aroma compounds. High-pressure processing has been used as an alternative and is capable of preserving the quality of fresh products much better (Donsi et al., 1996). High hydrostatic pressure treatment reduces the microbial counts and enzyme activity and affects product functionality (Hoover et al., 1989; Cheftel, 1990; Farr, 1990). Thus, it could be used potentially in developing new processes for food preservation or in product modifications (Mertens and Knorr, 1992). The first food products developed using high-pressure treatments were mostly plant products or food products containing plants (Knorr, 1995). In 1990, Meidi-ya Food Co. (Osaka, Japan) introduced apple, strawberry, and kiwi jams that had been sterilized using pressure alone (Mozhaev et al., 1994). Ogawa et al. (1989a, 1990) reported that high-pressure treatment could sterilize juices from various citrus fruits without any major changes in their nutritive components, natural flavor, or taste. Also, these authors reported that some enzymes, such as pectinesterase, were not completely inactivated after pressurization at 3000 or 4000 bar for 10 min, but instead were partially inactivated and thus did not recover under ordinary conditions of storage and commercialization. The application of combined high-pressure and -temperature treatments in the processing of fruitand vegetable-derived products, in some cases without additives, represents an important objective for food researchers and industrial companies. The future of this emerging technology will be closely related to the combined hurdle concept in application, where high pressure, temperature, natural additives, and other new hurdles must be taken into account for the development of improved or new plant food products.