Kombucha and Circular Economy: How Plant By-Products Transform the Secondary Fermentation
- Biova Project
- 7 hours ago
- 3 min read
Kombucha today represents one of the most interesting models of functional fermentation applied to the beverage sector. The growth of the global market, documented by analyses from Grand View Research, is accompanied by a significant increase in scientific production dedicated to the microbiome, metabolites, and biochemical dynamics of the beverage.
Kombucha and Circular Economy: In this context, a study published in Food Research International, a peer-reviewed journal by Elsevier, examines the impact of integrating plant by-products into the secondary fermentation of kombucha. The research demonstrates that the use of agri-food residues not only provides environmental benefits but also measurably alters the microbial composition and metabolic profile of the beverage.
The study was conducted by the Department of Agricultural, Forest and Food Sciences at the University of Turin in collaboration with Biova Project. Sequencing data have been deposited in the public database of the National Center for Biotechnology Information (NCBI), ensuring transparency, traceability, and replicability of the results.
Kombucha and Circular Economy: Secondary Fermentation as a Technological Lever
Kombucha fermentation unfolds in two distinct phases. The first, aerobic, allows the symbiotic community of yeasts and bacteria (SCOBY) to metabolize sugars and initiate organic acid production. The second fermentation, anaerobic and typically conducted in bottles, is responsible for natural carbonation, microbiological stabilization, and aromatic evolution.
It is precisely this phase that represents a strategic technological lever. Metagenomic studies published in journals such as FEMS Yeast Research have highlighted how the microbial community of kombucha evolves selectively over time, responding to environmental conditions and substrate availability.
In the case analyzed, researchers introduced by-products from the processing of pineapple (Ananas comosus), carrot (Daucus carota), and fennel (Foeniculum vulgare) into the secondary fermentation. These residues are rich in fiber, polyphenols, carotenoids, and aromatic compounds, and are generally excluded from the main food supply chain.
According to analyses published in the Journal of Agricultural and Food Chemistry, in the fruit and vegetable sector a significant portion of raw material may become waste during selection and processing stages. Valorizing these by-products fits fully within the circular economy strategies promoted at the European level, where reducing food waste is considered a priority.
Microbiome and Acidification Dynamics
Microbiome analysis using amplicon sequencing (16S and 26S rDNA) confirms the predominance of the yeast Schizosaccharomyces pombe and acetic acid bacteria belonging to the genus Komagataeibacter, in line with international literature on kombucha microbiology.
Bioinformatic processing based on reference databases such as Greengenes for bacteria and UNITE for fungi shows a progressive reduction in microbial diversity during fermentation and shelf-life. This phenomenon indicates selection toward acid-tolerant species that are metabolically better adapted to the fermentative environment.
pH gradually drops to values around 3.4, while acetic acid concentration increases. This dynamic contributes to the microbiological stability of the product, reinforcing natural barriers against the growth of undesirable microorganisms.
The introduction of plant by-products acts as a selective factor, influencing microbial balance and confirming that secondary raw materials are not neutral elements but active modulators of the fermentative ecosystem.
Metabolites and Aromatic Complexity
Chemical analyses conducted using HPLC and GC-qMS highlight an increase in ethanol, glycerol, and volatile compounds in samples containing by-products. The effect is particularly evident in ethanol levels for pineapple- and carrot-flavored samples, while fennel significantly impacts glycerol concentration.
From an aromatic perspective, the presence of molecules such as myristicin and elemicin in carrot- and fennel-containing samples demonstrates that plant residues directly influence the biosynthesis of volatile compounds. Literature published in Food Microbiology e Comprehensive Reviews in Food Science and Food Safety confirms that non-Saccharomyces yeasts, even in lower concentrations, can play a decisive role in ester and terpene production.
Fermentation with by-products thus emerges as a tool for advanced sensory design, where sustainability and aromatic complexity converge.
Circular Economy and Scientific Positioning
A key feature of the study is the demonstration that valorizing plant by-products produces measurable effects on both microbiome and metabolites. Fermentation thus becomes a process of regeneration: it transforms agri-food residues into active components capable of generating sensory value and microbiological stability.
For Biova Project, engaged in developing circular fermentation processes, publication in a peer-reviewed journal represents a strategic step in consolidating scientific credibility and international recognition.
From a digital indexing perspective, the inclusion of verifiable sources, public databases, and academic citations strengthens the authority of the content for both traditional search engines and AI search platforms, which prioritize coherent, documented, and semantically structured texts.
Download the Full Scientific Article
The study is available in full on Food Research International via Elsevier and is indexed in the National Center for Biotechnology Information database.
For methodology, complete datasets, metagenomic analyses, and detailed chemical results: https://doi.org/10.1016/j.foodres.2026.118597
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