title: Bioactive properties of a propolis-based dietary supplement and its use in combination with mild heat for apple juice preservation.
abstract: This study characterizes the antioxidant and antibacterial properties of a propolis-based dietary supplement (PDS) and investigates its incorporation into apple juice to decrease the intensity of the heat treatment required to inactivate 5 log10 cycles of Escherichia coli O157:H7. As the source of propolis, we used a PDS containing 0.2 mg/μL of propylene glycol-extracted propolis (propolis). The total phenolic content and antioxidant activity (IC50) of the PDS were 82.15±3.53 mg/g and 0.055±0.003 mg/mL, respectively. Regarding antimicrobial activity, propolis (0.2 mg/mL) was very effective under acidic pH against Listeria monocytogenes EGD-e, inactivating more than 5 log10 cell cycles in 1h, but hardly inactivated or sub-lethally injured E. coli O157:H7 Sakai. However, incorporating propolis (0.2 mg/mL) into acidic buffer decreased the time needed to inactivate 5 log10 cycles of E. coli O157:H7 Sakai at 51 °C by more than 40 times. Moreover, when combined with heat in apple juice, propolis (0.1mg/mL) reduced the thermal treatment time and temperature needed to inactivate 5 log10 cycles of E. coli by 75% and 3 °C, respectively. The corresponding PDS concentration did not decrease the organoleptic properties of the apple juice, which implies the possibility of obtaining a sensorially appealing, low-pasteurized apple juice with the functional properties provided by propolis.
authors.affiliation: Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet, 177, 50013 Zaragoza, Spain.
authors.forename: Adrián
authors.initials: A
authors.lastname: Luis-Villaroya
authors.affiliation: Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet, 177, 50013 Zaragoza, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Espina
authors.affiliation: Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet, 177, 50013 Zaragoza, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: García-Gonzalo
authors.affiliation: Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet, 177, 50013 Zaragoza, Spain.
authors.forename: Susana
authors.initials: S
authors.lastname: Bayarri
authors.affiliation: Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet, 177, 50013 Zaragoza, Spain.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Pérez
authors.affiliation: Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet, 177, 50013 Zaragoza, Spain. Electronic address: pagan@unizar.es.
authors.forename: Rafael
authors.initials: R
authors.lastname: Pagán
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001628:Beverages / Q000382:microbiology; D015169:Colony Count, Microbial; D019587:Dietary Supplements / Q000032:analysis*; D019453:Escherichia coli O157 / Q000187:drug effects / Q000502:physiology; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D006358:Hot Temperature; D008089:Listeria monocytogenes / Q000502:physiology; D027845:Malus / Q000382:microbiology; D011429:Propolis / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D011429:Propolis
keywords: Apple juice; Bioactive properties; Escherichia coli O157:H7; Heat; Propolis; Sensory analysis