The use of ultraviolet radiation as a non-thermal treatment for the inactivation of alicyclobacillus acidoterrestris spores in water, wash water from a fruit processing plant and grape juice concentrate

摘要

Alicyclobacillus acidoterrestris is a non-pathogenic, spore-forming bacteriumthat can survive the commercial pasteurisation processes commonly usedduring fruit juice production. Surviving bacterial endospores germinate, growand cause spoilage of high acid food products. Fruit juices can be treatedusing ultraviolet light (UV-C) with a wavelength of 254 nm, which has agermicidal effect against micro-organisms. In this study, A. acidoterrestris wasinoculated into water, used wash water from a fruit processing plant and grapejuice concentrate. Ultraviolet dosage levels (J L−1) of 0, 61, 122, 183, 244, 305and 367 J L−1 were applied using a novel UV-C turbulent flow system. The UVtreatment method was shown to reliably achieve in excess of a 4 log10reduction (99.99%) per 0.5 kJ L-1 of UV-C dosage in all the liquids inoculatedwith A. acidoterrestris. The applied novel UV technology could serve as analternative to thermal treatments of fruit juices for the inactivation ofAlicyclobacillus spores as well as in the treatment of contaminated wash water used in fruit processing.