In recent years, scientific research and industries have been focusing on the application of biological treatments aimed at imparting functional properties to waste products from food industries according to the principles on which the circular economy model is based, namely, the recovery, valorisation, and reuse of wastes. This work aimed at exploring the possibility of valorising waters from the blanching process of dried navy beans through lactic acid fermentation using Lacticaseibacillus paracasei CBA L74 as a starter. Two samples at different solid concentrations (0.75 °Bx and 1.25 °Bx) were fermented, and, in both cases, a bacterial load of 8 Logs and a lactic acid concentration of approximately 1.3 g/L were reached, despite the lack of nutrients. An unusual pH trend, characterised by an initial decrease and unexpected final rise, was observed during the fermentation of both samples: simultaneously, an increase in protein content was observed, suggesting that the proteolytic action of the microorganism could be responsible for the release of pH-increasing substances. In both cases, a slight increase in total polyphenols (approximately 23.3–33.72%) and flavonoids (approximately 42.3–52%) due to fermentation was observed, with a corresponding improvement in antioxidant capacity (approximately 25.32–37.72%). A significant increase in saponin concentration was determined for the most concentrated blanching water (from 2.87 ± 0.28 to 6.68 ± 0.69 mgOAE/mL), leading to an improvement in foaming properties and an enhanced capacity to produce stable emulsions. The obtained results confirmed the possibility of reducing water consumption from blanching operations, as well as finding valorisation opportunities for this side stream through a safe and inexpensive fermentation treatment.

The concept of postbiotic has been attracting the attention of the scientific community and several industrial realities to develop new claims and new market segments for functional fermented products. The aim of this work was to develop a process to produce an oat-based postbiotic ingredient to be used in personal care cosmetic formulations. A hydrolyzed oatmeal suspension was fermented using Lacticaseibacillus paracasei CBA L74 as starter culture, at 37 °C for 48 h by controlling the pH; then the bacterial charge was inactivated by a mild thermal treatment at 80 °C for 30 s, obtaining a postbiotic. The effect of different process steps, hydrolysis, sterilization, fermentation, and inactivation phases, on lactic acid concentration, total polyphenolic content, antioxidant activity, tyrosinase inhibition activity and Sun Protection Factor value was investigated, demonstrating the potential cosmetic applications. The maximum bacterial growth and lactic acid production were achieved after 24 h of process, with a cell density and a lactic acid concentration of 3.05 × 10⁹ CFU/mL and 8.60 g/L, respectively. The total phenolic content and the antioxidant activity reached their maximum values (2.5 mgGAE/mL, EC₅₀ = 2.2 mg/mL and 1.38 × 10⁻² mmol Fe²⁺/g and 7.3 × 10⁻³ mmol TE/g, respectively) after the sterilization treatment; the maximum tyrosinase inhibition of 50.6%, corresponding to a sample concentration of 16 mg/mL, was found after 24 h of fermentation process. Fermentation did not show an impact on UV shielding ability and the SPF value decreased during the process.

Postbiotics, a type of fermented functional food, are attracting attention alongside the more common pro- and prebiotics. The main production stages—fermentation, thermal inactivation, and drying—significantly influence the functional effects of these foods. This study investigated the impact of pH control during the fermentation of oat flour suspension and optimized spray-drying parameters to produce oat-based postbiotic powders. A Lacticaseibacillus paracasei CBA L74 fermented hydrolyzed oat suspension was analyzed at 37 °C for 24 h, with and without pH control. Both pH conditions produced similar bacterial growth (~10⁹ CFU/mL) and lactic acid (~9 g/L). No significant differences were observed in polyphenols, flavonoids, or antioxidant activity, indicating that pH control did not noticeably improve productivity or the phytochemical properties. The best results—57.40% drying yield and 3.9% relative humidity—were achieved when the postbiotic suspension (diluted 1:4 with water) was mixed 1:1 with maltodextrins, and the spray drying process was conducted with 50 L/min air flow, 200 °C, 3.2 bar atomization pressure, and 5 L/min feed flow. These results support the possibility of scaling the production process from laboratory-optimized parameters and represent a first step toward a cost-effective and industrially feasible route for manufacturing stable oat-based postbiotic powders.

According to the main principles of the circular economy, recovering bioactive compounds from food waste has significant potential to deliver financial, environmental, and health benefits by incorporating them into food products as additives, emulsifiers, antioxidants, and antimicrobial agents to enhance nutritional and functional value and/or extend product shelf life. This work investigated the potential of a food waste material, such as chickpea aquafaba from industrial processing, as a fermentation substrate using promising lactic acid bacteria, including L. plantarum AME-01, L. paracasei CBA L74, and L. mesenteroides, under non-controlled pH conditions, and evaluated the antioxidant/chelating capacity of the postbiotic obtained from the process. Fermented substrates were thermally inactivated to produce postbiotic preparations, which were characterized in terms of inactivated biomass and lactic acid concentration. Subsequently, liquid postbiotics were spray-dried using a lab-scale spray dryer, and the resulting powders were characterized in terms of antioxidant and chelating properties. While the postbiotic preparations using L. paracasei CBA L74 showed significantly lower activity (23.78 ± 7.25%) compared to non-fermented aquafaba (56.85 ± 2.79%), those using L. plantarum AME-01 (84.60 ± 5.57%) and L. mesenteroides (82.56 ± 1.11%) exhibited increased chelating activity. The antioxidant power of all fermented powders was significantly improved, confirming the potential of postbiotic ingredients as stabilizing additives in food formulations.

The aim of this study was to design an innovative oat fermentation process using capsules to produce postbiotics with anti-inflammatory and antioxidant potential. Capsule fermentation led to higher bacterial growth (3.30*10⁹ CFU/mL) and lactic acid production (20.49 mg/mL), compared to traditional free-cell fermentation (4.73*10⁸ CFU/mL and 9.08 mg/mL, respectively), along with increased cell and product yields. The dried postbiotics were also subjected to in vitro digestion, mimicking the gastrointestinal one. A functional characterization of the four postbiotics, undigested and digested postbiotics from both capsule and free-cell fermentation, was performed using the HCT116 colon cell line. All four products prevented LPS- induced activation of the inflammatory pathway, protein oxidative damage, and impaired glutathione reductase activity, with digested postbiotics being more effective than undigested ones. These findings demonstrate that the capsule-based postbiotic is a promising candidate as a functional food with potential applications in nutraceuticals, animal feeding, and cosmetics.