title: Increased inactivation of exopolysaccharide-producing Pediococcus parvulus in apple juice by combined treatment with enterocin AS-48 and high-intensity pulsed electric field.
abstract: The cyclic peptide bacteriocin enterocin AS-48 was tested (at final concentrations of 0.175, 0.613, and 1.05 AU/ml) against the exopolysaccharide-producing cider spoilage strain Pediococcus parvulus 48 in apple juice in combination with high-intensity pulsed electric field (HIPEF) treatment (35 kV/cm and 150 Hz for 4 mus and bipolar mode). The effect of the combined treatments was studied by surface response methodology, with AS-48 concentration and HIPEF treatment time as process variables. A bacteriocin concentration of 0.613 AU/ml in combination with HIPEF treatment time of 1,000 micros reduced the population of pediococci by 6.6 log cycles in apple juice and yielded an apple juice that was free from pediococci during a 30-day storage period at 4 and 22 degrees Celsius. In contrast, application of HIPEF treatment alone had no effect on the surviving pediococci during storage of juice at 22 degrees Celsius. The combined treatment significantly improved the stability of the juice against spoilage by exopolysaccharide-producing P. parvulus.
authors.affiliation: Area de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071-Jaén, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Martínez Viedma
authors.forename: Angel
authors.initials: A
authors.lastname: Sobrino López
authors.forename: Nabil
authors.initials: N
authors.lastname: Ben Omar
authors.forename: Hikmate
authors.initials: H
authors.lastname: Abriouel
authors.forename: Rosario
authors.initials: R
authors.lastname: Lucas López
authors.forename: Olga
authors.initials: O
authors.lastname: Martín Belloso
authors.forename: Antonio
authors.initials: A
authors.lastname: Gálvez
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D001628:Beverages / Q000382:microbiology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D004574:Electromagnetic Fields; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D006801:Humans; D027845:Malus / Q000382:microbiology; D010376:Pediococcus / Q000187:drug effects* / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D011135:Polysaccharides, Bacterial; C466236:enterocin AS-48, Enterococcus faecalis; C085953:exopolysaccharide, Bacillus