In addition to fulfilling their function of giving color, many natural pigments are known as interesting bioactive compounds with potential health benefits. These compounds have various applications. In recent times, in the food industry, there has been a spread of natural pigment application in many fields, such as pharmacology and toxicology, in the textile and printing industry and in the dairy and fish industry, with almost all major natural pigment classes being used in at least one sector of the food industry. In this scenario, the cost-effective benefits for the industry will be welcome, but they will be obscured by the benefits for people. Obtaining easily usable, non-toxic, eco-sustainable, cheap and biodegradable pigments represents the future in which researchers should invest.

The global concern about the use of disposable plastics has fed the research on sustainable packaging for food products. Among the virtuous materials, chitosan emerges as a valid alternative to conventional polyethylene films because of its abundance in nature. In this work, a novel film for food wrapping was developed by exploiting shellfish waste according to a vision of circular economy. Compared to previous studies, here, novel ingredients, such as polyvinyl alcohol (PVA), fibroin, and essential oils, were used in a synergistic combination to functionally postpone cheese deterioration. The fermentative procedure applied for the obtainment of chitin contributes to filling the existing gap in the literature, since the majority of studies are based on the chemical pathways that dramatically impact the environment. After pretreatment, the shrimp shell waste (SSW) was fermented through two bacterial strains, namely Lactobacillus plantarum and Bacillus subtilis. A deacetylation step in an alkaline environment transformed chitin into chitosan, yielding 78.88 g/kg SWW. Four different film formulations were prepared, all containing chitosan with other ingredients added in order of decreasing complexity from the A to D groups. The novel films were tested with regard to their physico-mechanical and antioxidant properties, including the tensile strength (12.10–23.25 MPa), the elongation at break (27.91–46.12%), the hardness (52–71 Shore A), the film thickness (308–309 μm), and the radical scavenging activity (16.11–76.56%). The performance as a cling film was tested on two groups of cheese samples: the control (CTR), wrapped in conventional polyethylene (PE) film; treated (TRT), wrapped in the chitofilm formulation deemed best for its mechanical properties. The volatiles entrapped into the headspace were investigated by means of the SPME-GC technique. The results varied across soft, Camembert, and semi-hard cheeses, indicating a growing abundance of volatiles during the conservation of cheese. The bacterial growth trends for mesophilic, enterobacteriaceae, and lactic acid bacteria were expressed as the mean colony forming units (CFU)/mL for each type of cheese at different sampling times (day 2, day 8, and day 22): the highest load was quantified as 8.2 × 10⁶ CFU/mL at day 22 in the CTR Camembert cheese. The TRT samples generally exhibited inhibitory activity comparable to or lower than that observed in the CTR samples. The sensory analysis revealed distinctions in cheese taste between the TRT and CTR groups.

Opuntia ficus-indica cladodes are by-products which contain high amounts of fibres, bioactive and functional compounds. Given their high annual productivity per hectare, cladodes represent a cheap and suitable substrate, usable for fermentation processes. We investigated their potential as a substrate for the growth and production of lactic acid from Lactobacillus acidophilus LA-5. A separate hydrolysis and fermentation was performed. The concentration of reducing sugars obtained after the dilute acid and enzymatic hydrolysis was 28.45 g/L. The lactobacillus count ranged from 6.03 to 8.1 log CFU/mL, whereas lactic acid yield and productivity were 0.63 g/g and 0.73 g/L h, respectively. The maximum lactic acid concentration was found to be 17.5 g/L. This study reports the possibility of using the O. ficus indica cladode for lactic acid production by LA-5 aiming to reduce costs for sustainable industrial production.

Natural astaxanthin is a bioactive with high antioxidant power, widely suitable for many applications. This study explores the potential of leftover food as a sustainable and low-cost substrate for producing astaxanthin via direct fermentation using Phaffia rhodozyma. The pretreated and characterized raw materials were fermented in a lab-scale bioreactor under optimized process conditions. The entire process (168 h) was monitored in terms of reducing sugar consumption, yield, and productivity of astaxanthin. The implemented experimental plan achieved high astaxanthin yield and producticity, namely, 230 mg·L⁻¹ and ~1.6 mg·L⁻¹·h, which were attained at 150 h, respectively, with a substrate consumption of around 90% for all samples. The natural astaxanthin obtained showed interesting antioxidant activity, exhibiting a radical scavenging activity of more than 65%, which was evaluated with a DPPH assay. This process not only offers a promising solution for leftover food valorization but also provides a sustainable approach to producing bioactive compounds with significant health value, paving the way for further industrial applications in food, pharmaceutical, and cosmetic sectors.

A functional seafood product was obtained by biofortifying fish fillets with polyphenols extracted from artichoke by-products. Two fortification techniques—vacuum immersion (VI) and spray coating followed by electroporation (SCE)—were applied and compared with untreated control (CTR) samples. The treated by vacuum immersion (TRT-VI) group showed the highest antioxidant power (DPPH scavenging: 42.5 ± 3.2% vs. 19.6 ± 1.5% in CTR. Colorimetry revealed significant shifts in lightness (L*), red-green component (a*), and yellow-green component (b*) values in raw and cooked fillets. In the TRT-VI group the microbiological shelf life was extended by approximately 4–5 days. Sensory analysis revealed that, despite of bitterness and astringency, key attributes were maintained. Phenolic profiling identified caffeoylquinic acids as the dominant compounds in both artichoke extracts and fortified fillets (range 0.5–304.5 mg·100 g⁻¹). In this study the development of functional seafood products has been implemented through the valorisation of an agri-food by-product and the exploitation of emerging fortification technologies. Key outputs include the assessment of the nutritional value of the fortified fish fillets and the extension of shelf life without compromising key sensory attributes. Future studies could be directed toward the optimisation of formulations and bioavailability of the incorporated polyphenols.

Date palm is an age-old cultivated plant that thrives in tropical and subtropical regions. The date palm is a bountiful source of carbohydrates, encompassing sucrose, glucose, and fructose and proteins. The date industry generates a significant volume of unused by-products. Dates offer a diverse range of by-products beyond the agri-food sector. LAB have garnered extensive utilisation across diverse food sectors, spanning meat, vegetables, beverages, dairy products, and other fermented foods. In the quest for establishing a new large-scale fermentation process for lactic acid there has been a concerted effort to utilise more cost-effective medium components. In the present work, date palm residue (DPR) derived from date palm fruit, after sugar extraction, was incorporated into MRS. The fermentation process was executed through two distinct fermentation systems. Initially, experiments were conducted in flasks. Afterward, the optimal conditions for bacterial growth were determined, and the experiment was carried out using a bioreactor. DPR supported the probiotic Lactobacillus spp. growth especially after 48 h incubation. The prebiotic effect of DPR on Lactobacillus spp. was reported. An increase in the total number of bacterial populations was observed in response to the addition the DPR until 48 h. Specifically, the supplementing DPR at a concentration of 1.5% in batch fermentation enhanced the growth and lactic acid production of Lactobacillus casei. This study suggests that DPR could potentially function as an economical prebiotic source and could be seamlessly incorporated as a functional food ingredient, thereby transforming a waste product into an economically sustainable food substrate.