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Modulation of the bacterial population in commercial cucumber fermentations by brining salt type
Author(s) -
PérezDíaz I.M.,
Dickey A.N.,
Fitria R.,
Ravishankar N.,
Hayes J.,
Campbell K.,
Arritt F.
Publication year - 2020
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.14597
Subject(s) - fermentation , food science , weissella , lactococcus , leuconostoc , population , chemistry , lactobacillaceae , pediococcus , lactococcus lactis , lactobacillus , bacteria , lactic acid , biology , demography , sociology , genetics
Aims Differences in the bacterial population of cucumber fermentations brined with no salt, 100 mmol l −1 (1·1%) calcium chloride (CaCl 2 ) or 1·03 mol l −1 (6%) sodium chloride (NaCl) were studied. Methods and Results Changes in the microbiology and chemistry of commercial and laboratory scale cucumber fermentations occurring as a function of time were monitored using colony counts and metagenetic analysis, and a pH probe and high‐performance liquid chromatography analysis respectively. Dissolved oxygen and carbon dioxide content were monitored in commercial fermentations. Fermentations brined with calcium chloride (CaCl 2 ) or no salt sustained faster microbial growth and reduction in pH than those brined with 1·03 mol l −1 NaCl. Leuconostoc , Lactococcus and Weissella dominated in fermentations brined with no salt or 100 mmol l −1 CaCl 2 on day 1 as compared to Weissella and enterobacteria in fermentations containing 1·03 mol l −1 NaCl. Lactobacilli dominated all fermentations by the third day, regardless of salt type, and was followed, in relative abundance by Pediococcus , Leuconostoc , Lactococcus and Weissella . From 84 to 96% of the population was composed of Lactobacillus by day 7 of the fermentations, except in the no salt fermentations in which a mixed population of LAB remained. The population of LAB found in commercial cucumber fermentations brined with 100 mmol l −1 CaCl 2 ( n = 18) or 1·03 mol l −1 NaCl ( n = 9) mimicked that of laboratory fermentations. A declining population of aerobes was detected in commercial fermentations brined with CaCl 2 on day 1. Conclusion A reduced NaCl content in cucumber fermentation enhances microbial diversity. Significance and Impact of the Study This study fills a knowledge gap and aids in the design of improved reduced NaCl cucumber fermentations.