title: Impact of NaCl reduction on lactic acid bacteria during fermentation of Nocellara del Belice table olives.
abstract: Table olives are widely consumed worldwide but, due to the presence of NaCl in fermenting brines, they contain high levels of sodium. A promising strategy to lower sodium content is the reduction or substitution of NaCl in brines with other chlorides. However, these procedures may impact safety, spoilage, as well as quality and technological properties, including the evolution and final composition of the fermenting microbiota. In the present work the effects of partially replacing NaCl with KCl in fermenting brines on the microbiological quality of Nocellara del Belice olives produced by Spanish style (Sivigliano) or Castelvetrano methods have been analyzed. In both cases, the fermentation steps were performed in parallel, in brines containing either NaCl alone, or partially replaced with different proportions of KCl (25, 50 and 75%), while maintaining a final saline concentration of 9% (Sivigliano method) or 7% (Castelvetrano). To compare microbial dynamics in the experimental brines, changes in bacterial ecology were monitored during fermentation with a polyphasic approach, including both microbiological methods and culture-independent techniques based on DGGE and NGS analysis. The main microbial groups detected in the olive microbiota from both production procedures were LAB and yeasts. Overall, the data demonstrate that partial replacement of NaCl with KCl does not increase the risk of contamination, nor the overgrowth of pathogens or spoiler microbes.
authors.affiliation: CREA-NUT Food and Nutrition Research Center, Via Ardeatina 546, 00178 Rome, Italy. Electronic address: paola.zinno@crea.gov.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Zinno
authors.affiliation: CREA-NUT Food and Nutrition Research Center, Via Ardeatina 546, 00178 Rome, Italy. Electronic address: barbara.guantario@crea.gov.it.
authors.forename: Barbara
authors.initials: B
authors.lastname: Guantario
authors.affiliation: CREA-NUT Food and Nutrition Research Center, Via Ardeatina 546, 00178 Rome, Italy. Electronic address: giuditta.perozzi@crea.gov.it.
authors.forename: Giuditta
authors.initials: G
authors.lastname: Perozzi
authors.affiliation: CREA-NUT Food and Nutrition Research Center, Via Ardeatina 546, 00178 Rome, Italy. Electronic address: gianni.pastore@crea.gov.it.
authors.forename: Gianni
authors.initials: G
authors.lastname: Pastore
authors.affiliation: CREA-NUT Food and Nutrition Research Center, Via Ardeatina 546, 00178 Rome, Italy. Electronic address: chiara.devirgiliis@crea.gov.it.
authors.forename: Chiara
authors.initials: C
authors.lastname: Devirgiliis
mesh_terms: D044822:Biodiversity; D019149:Bioreactors; D005285:Fermentation; D005516:Food Microbiology; D059022:Food Safety; D006863:Hydrogen-Ion Concentration; D007777:Lactobacillaceae / Q000187:drug effects* / Q000235:genetics; D064307:Microbiota / Q000235:genetics / Q000502:physiology*; D031658:Olea / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011189:Potassium Chloride / Q000032:analysis / Q000494:pharmacology; D012492:Salts / Q000737:chemistry*; D012965:Sodium Chloride / Q000032:analysis* / Q000494:pharmacology; D015003:Yeasts / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology
chemical_list: D012492:Salts; C017082:brine; D012965:Sodium Chloride; D011189:Potassium Chloride
keywords: Castelvetrano; Halophilic bacteria; KCl; Lactic acid bacteria; Sivigliano