title: Characterization of the microbial diversity in yacon spontaneous fermentation at 20 °C.
abstract: The prebiotic fructooligosaccharide content of yacon makes this root an attractive alternative for the supplementation of a variety of food products. The preservation of yacon by fermentation has been proposed as an alternative to increase the probiotic content of the root concomitantly with its shelf life. Thus the fermented yacon could have significant functional content. The objective of this research was to characterize the biochemistry and microbiology of spontaneous yacon fermentation with 2% NaCl and define the viability of the proposed process. The biochemical analysis of spontaneous heterolactic fermentation of yacon showed a progressive drop in pH with increased lactic and acetic acids, and the production of mannitol during fermentation. The microbial ecology of yacon fermentation was investigated using culture-dependent and culture-independent methods. Bacterial cell counts revealed a dominance of lactic acid bacteria (LAB) over yeasts, which were also present during the first 2 days of the fermentation. Results showed that the heterofermentative LAB were primarily Leuconostoc species, thus it presents a viable method to achieve long term preservation of this root.
authors.affiliation: Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695, United States. Electronic address: ldreina@yahoo.com.
authors.forename: L D
authors.initials: LD
authors.lastname: Reina
authors.affiliation: USDA-Agriculture Research Service, SAA, Food Science Research Unit, 322 Schaub Hall-NCSU, Raleigh, NC 27695, United States.
authors.forename: I M
authors.initials: IM
authors.lastname: Pérez-Díaz
authors.affiliation: USDA-Agriculture Research Service, SAA, Food Science Research Unit, 322 Schaub Hall-NCSU, Raleigh, NC 27695, United States.
authors.forename: F
authors.initials: F
authors.lastname: Breidt
authors.affiliation: Microbiome Core Facility, Department of Cell Biology and Physiology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, United States.
authors.forename: M A
authors.initials: MA
authors.lastname: Azcarate-Peril
authors.affiliation: Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695, United States; Department of Food Biotechnolgy, Instituto de la Grasa, CSIC, Seville, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Medina
authors.affiliation: Microbiome Core Facility, Department of Cell Biology and Physiology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, United States.
authors.forename: N
authors.initials: N
authors.lastname: Butz
mesh_terms: D019659:Asteraceae / Q000382:microbiology*; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics; D058491:Bacterial Load; D018407:Bacterial Physiological Phenomena; D044822:Biodiversity; D005285:Fermentation; D064307:Microbiota / Q000187:drug effects / Q000502:physiology; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012965:Sodium Chloride / Q000494:pharmacology; D013997:Time Factors; D015003:Yeasts / Q000187:drug effects / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S; D012337:RNA, Ribosomal, 18S; D012965:Sodium Chloride
keywords: Fermented vegetables; Heterolactic fermentation; Lactic acid bacteria