Microbial and Metabolic Dynamics during Fermentation of Vinegar with Rye Bread

Area of Science:

• Food Science
• Microbiology
• Fermentation Technology

Background:

• Vinegar, an acidic fermented product, is made from various sources.
• Investigating novel substrates like rye bread for vinegar production is crucial for food sustainability.

Purpose of the Study:

• To compare spontaneous and backslopping fermentation dynamics for rye bread vinegar.
• To characterize microbial and metabolite profiles during rye bread fermentation.

Main Methods:

• Two fermentation methods (spontaneous and backslopping) were used with rye bread.
• Analysis included pH, microbial community composition, and metabolite profiling at different fermentation stages.

Main Results:

• Both methods decreased pH below 3.5 with increased microbial abundance, more so in the inoculated batch.
• Acetobacter dominated late stages; distinct microbial communities were observed between spontaneous (Clostridium, Gluconacetobacter) and inoculated (Leuconostoc, Lactobacillus, Gluconobacter, Pichia, Wickerhamomyces) batches.
• Acetic acid was the predominant late-stage metabolite; volatile profiles differed significantly, with specific compounds enriched in each batch.

Conclusions:

• Rye bread can be fermented into vinegar using both spontaneous and inoculated methods.
• Backslopping inoculation enhances microbial dynamics and metabolite production.
• Rye bread presents a viable substrate for sustainable vinegar production, utilizing upcycled food resources.