Effect of ultraviolet (UV-C) radiation on spores and biofilms of Alicyclobacillus spp. in industrialized orange juice

• Published in: International journal of food microbiology Vol. 305; p. 108238
• Main Authors: Prado, Daniela Biral do, Szczerepa, Márcia Maria dos Anjos, Capeloto, Otávio Augusto, Astrath, Nelson Guilherme Castelli, Santos, Naiara Caroline Aparecido dos, Previdelli, Isolde Terezinha Santos, Nakamura, Celso Vataru, Mikcha, Jane Martha Graton, Abreu Filho, Benício Alves de
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 16-09-2019; Elsevier BV
• Subjects: Alicyclobacillus; Alicyclobacillus acidocaldarius; Alicyclobacillus acidoterrestris; Biofilms; Food processing industry; Fruit juices; Juices; Orange juice; Oranges; Reduction; Rubber; Scanning electron microscopy; Spores; Stainless steel; Stainless steels; Ultraviolet radiation; Ultraviolet-C; Alicyclobacillus; Biofilms; Ultraviolet-C; Orange juice; Spores
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2019.108238

Bacteria of the genus Alicyclobacillus pose serious quality problems for the juice processing industries that have sought effective alternatives for its control. The present study evaluated the effect of UV-C radiation on the reduction of spores and biofilm formation of Alicyclobacillus spp. on stainless steel and rubber surfaces using industrialized orange juice as a culture medium. Four reference Alicyclobacillus spp. species and different UV-C dosages were investigated. After exposed for 20 min (16.8 kJ/m2) to UV-C, the spores of Alicyclobacillus acidoterrestris, Alicyclobacillus herbarius, and Alicyclobacillus cycloheptanicus decreased drastically more of 4 log CFU/mL, with counts below the detection limit of the method (<1.7 log CFU/mL), while the Alicyclobacillus acidocaldarius spores were more sensitive to UV-C, once this spore reduction was observed within 15 min (12.6 kJ/m2). Morphological changes in the Alicyclobacillus acidoterrestris spores were observed by scanning electron microscopy. A reduction of biofilm formation was observed for all UV-C treatments, and the higher reductions (approximately 2 log CFU/mL) were found for the Alicyclobacillus acidocaldarius species after 30 min (26.2 kJ/m2), on the stainless steel and rubber surfaces. The results suggest that UV-C can be used to reduce the biofilm formation and could be a promising alternative for controlling Alicyclobacillus spp. spores in industrialized orange juice.
•Efficiency of UV-C radiation in reconstituted orange juice was examined.•Alicyclobacillus spp. are vulnerable to UV-C.•External morphological changes were observed with UV-C.•UV-C can be promising to treatment Alicyclobacillus spp. spores and biofilms.