Fermentation of agri-food by product/waste to obtain bioactive compounds enriched foods

The fermentative approach represents a valuable and sustainable strategy to recover and valorize agri-food by-products and waste. The bioconversion process by bacteria, yeast and moulds, contributes to improving the availability of bioactive compounds (such as proteins, amino acids, peptides, inulin, phenolic compounds, and antimicrobials) in waste matrices and the shelf-life and safety of innovative derived food products. Food by-products and waste can also be a valuable source of beneficial microorganisms with functional biotechnological traits and able to produce metabolites with biological properties. In this project, fermentative procedures will be developed using selected bacterial (i.e. LAB), yeast, and/or fungal strains to treat waste matrices deriving from different agri-food chains aimed to develop innovative food ingredients/products with high added value. Furthermore, the characteristics of the microbial population and its dynamics in spontaneous or controlled fermentations will be examined to optimize bioconversion processes.

The activity will focus on three main topics.

Isolation and characterization of bacteria/yeasts/moulds from agri-food by-products /waste.
1) Identification and selection of bacteria and yeasts from by-products of the artichoke production chain (outer bracts, stalks), able to carry out fermentation (CNR).
2) Genomic analyses of fungal genera (Aspergillus, Fusarium, Penicillium) contaminating cereal by-products and/or waste from the malting industry for the prediction of the potential production of microbial bioactive compounds (CNR).

Optimization of fermentative processes for the development of innovative food ingredients/products.
1) Spontaneous microflora, selected bacteria/yeasts, and LAB strains (e.g., Lactiplantibacillus plantarum) will be used for the fermentation of by-products/waste from agri-food chains (cereals, artichokes, legumes, coffee, tomato, grape pomace, apple, malting industry) to obtain fermented products (bread, cereal, bakery products, patè, beverages) enriched in bioactive compounds (polyphenols, carotenoids, anthocyanins, riboflavin, inulin, proteins, amino acids, exopolysaccharides, organic acids, carbohydrates, fibers) and improved nutritional/technological/sensorial/digestibility/nutritional value (CNR).
2) Selected by-products will be subjected to the auto-hydrolysis process before fermentation after assessing the optimal operating conditions based on times, temperatures, and solid-to-liquid ratios (UNICAT).

Characterization of microbial population dynamics in fermented matrices.
The microbial population dynamics in some fermented matrices (tomato/grape pomace, artichoke residues) will be studied and monitored by applying high-throughput sequencing technologies and metagenomics analysis. The evolution of the microbial population will be linked to the increased bioaccessibility of bioactive compounds in the fermented matrices (CNR).

1. Selection and collection of bacteria/yeast/moulds species/strains isolated from agri-food by-products/waste based on their biotechnological characteristics and ability to produce bioactive metabolites suitable to be used in fermentative processes.

2. Development of fermentative processes and definition of optimized procedures for producing food ingredients/ products enriched in bioactive compounds.

3. Production of at least one bread product and/or cereal product supplemented with fermented waste material and showing improved shelf-life/digestibility/nutritional value.

4. Identification of the optimal operating conditions of the autohydrolysis process before fermentation.

5. Characterization of bioactive compounds produced during fermentative processes.

6. Report on the potential pro-technological use of selected lactic acid bacteria for biocontrol activities.

7. Characterization of microbial population composition and dynamics of agri-food by-products/waste fermented by naturally present microbiota or selected microbial strains.