PEF research extends apple juice shelf life.Pulsed electric field (PEF PEF peak expiratory flow. ) technology has received a lot of attention in Europe as well as in the United States. This technology inactivates microorganisms and decreases the activity of enzymes in liquid foods, thus increasing the shelf life of treated food products. It causes minimal undesirable changes in food products. The objective of a study at the Central Food Research Institute (Department of Nutrition, Department of Microbiology and Postharvest Technology, Herman Otto ut 15, H-1022 Budapest, Hungary) was to investigate the effect of this technique on the physical, chemical and microbial microbial pertaining to or emanating from a microbe. microbial digestion the breakdown of organic material, especially feedstuffs, by microbial organisms. properties of apple juice. The effects of electric field strength, the number of pulses and the total treatment time were studied on the organoleptic or·gan·o·lep·tic adj. 1. Relating to perception by a sensory organ. 2. Involving the use of sense organs. organoleptic properties, color, flavor, malic acid malic acid: see Krebs cycle. content, vitamin C vitamin C or ascorbic acid Water-soluble organic compound important in animal metabolism. Most animals produce it in their bodies, but humans, other primates, and guinea pigs need it in the diet to prevent scurvy. content, nonenzymatic browning index, hydroxymethylfurfurol content, microbial condition and shelf life of apple juices. Researchers studied the effect of PEF treatment on the microbial condition and shelf life of apple juice samples inoculated with Saccharoryces cerevisiae. The PEF operating conditions, primarily the electric field strength, significantly influenced microbial levels and shelf life without creating undesirable changes in physical and chemical properties. By applying 8.3 pulses of 25 kV/cm or 28 kV/cm electric field intensity, the researchers were able to achieve about 3 log cycles inactivation inactivation /in·ac·ti·va·tion/ (in-ak?ti-va´shun) the destruction of biological activity, as of a virus, by the action of heat or other agent. of inoculated S. cerevisiae. At a fixed electric field intensity (20 kV/cm), the microbial count of S. cerevisiae decreased when scientists increased the number of pulses from 8.3 to 10.4. By using 10.4 pulses at 20 kV/cm electric field intensity, the microbial count of S. cerevisiae decreased by about 4 log cycles. The PEF treatment (28 kV/cm electric field intensity, 8.3 pulses) extended the shelf life of the S. cerevisiae-inoculated apple juice by five days at 5 C storage. There was no significant change in the physical and chemical properties of PEF-treated apple juice. The organoleptic test showed no significant differences between the treated and untreated samples. Further information. Zsuzsanna Cserhalmi; phone: +36 1 355 8244; fax +36 1 212 9853 URL URL in full Uniform Resource Locator Address of a resource on the Internet. The resource can be any type of file stored on a server, such as a Web page, a text file, a graphics file, or an application program. : www.cfri.hu. |
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