This work was performed to study Castilla Rose (Purshia plicata) as a potential source of polyphenols obtained by solid-state fermentation (SSF)-assisted extraction using the microorganism Aspergillus niger GH1 and to evaluate the antioxidant activity of the extracted compounds. First, water absorption capacity (WAC) of the plant material, radial growth of the microorganism, determination of best fermentation conditions, and maximum accumulation time of polyphenols were tested. Then, a larger-scale fermentation, polyphenols isolation by column liquid chromatography (Amberlite XAD-16) and recovered compounds identification by HPLC-MS were made. Finally, the antioxidant activity of the recovered compounds was tested by ABTS, DPPH, and lipid oxidation inhibition assays. The best fermentation conditions were temperature 25 °C and inoculum 2 × 10⁶ spores/g, while the maximum extraction time of polyphenols was 24 h (173.95 mg/g). The HPLC/MS analysis allowed the identification of 25 different polyphenolic compounds, and the antioxidant activity of the obtained polyphenols was demonstrated, showing ABTS assay the most effective with inhibition of 94.34%.

This study investigated the influence of process parameters on the recovery of phenolic compounds and antioxidant activity from pineapple peel using green extraction technologies: ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE). A two-level factorial design was used to evaluate the effects of the solvent-to-solid ratio, time, temperature, ethanol concentration, and power on the yield of hydrolyzable and condensed polyphenols. The extracts were characterized using HPLC-MS, and their antioxidant activity was assessed using DPPH, ABTS, and FRAP assays. UAE yielded the highest condensed polyphenol content (323.82 mg/g), while MAE extracts demonstrated superior antioxidant activity (FRAP: 90.40 mgEqTrolox/g). The predominant compound identified using both methods was 1-caffeoylquinic acid. The most influential variable in UAE was the solvent-to-solid ratio, whereas extraction time was the most significant variable in MAE. These findings highlight the potential of pineapple peel valorization through sustainable extraction methods, with UAE favoring phenolic yield and MAE enhancing bioactivity, thereby supporting their application in the food and nutraceutical industries.

The giant reed (Arundo donax) is a fast-growing plant adapted to different climatic and soil conditions; although its origin is Asian, the species has spread throughout the world. During its development, it consumes three times more water than typical native vegetation and is responsible for changing the landscape of riparian areas; the high biomass productivity and the annual harvest period make this crop an alternative to produce and/or extract industrial bioproducts. The main objective of this research was to evaluate the feasibility of using giant reed in a bioprocess that produces enzymes by a solid-state fermentation experiment, four fungal species were tested (Aspergillus niger GH1, Aspergillus niger PSH, Trichoderma harzianum, and Rhizopus oryzae); enzyme activities were performed using reported methodologies varying only reaction volumes. The A. niger GH1 and PSH strains were the best adapted to the plant material, A. niger GH1 was capable to produce 4 of the 5 evaluated enzymes (cellulase-endoglucanase (174.39 ± 19.62 U/L), xylanase (1313.31 ± 39.25 U/L), invertase (642.22 ± 23.55 U/L), and polyphenol oxidase (6094.01 ± 306.54) while A. niger PSH was able to produce 3 of the 5 evaluated enzymes (cellulase-endoglucanase (147.09 ± 13.88 U/L), xylanase (1307.76 ± 31.40 U/L), and invertase (603.92 ± 3.14 U/L).

Rambutan peel, an abundant agro-industrial by-product, is a rich source of ellagitannins (ETs) and represents a promising substrate for the sustainable production of ellagic acid (EA) through solid-state fermentation (SSF). This study aimed to optimize EA release from rambutan peel ETs by SSF using Saccharomyces cerevisiae 227 in column reactors. We applied a central composite design (CCD) to evaluate and optimize the effects of temperature, NaCl concentration, and peptone supplementation on EA production. We also used HPLC/ESI/MS to identify and quantify EA. Maximum EA yields were obtained under central experimental conditions (treatments 15 and 16: 35 °C, 0.53 g/L NaCl, and 8 g/L peptone), reaching 8.36 ± 1.58 and 8.23 ± 0.52 mg/g, respectively. The predictive model estimated a maximum EA production of 8.29 mg/g, experimentally validated, at 34.6 °C, 0.58 g/L NaCl, and 8.26 g/L peptone, yielding 8.27 ± 0.47 mg/g. HPLC/ESI/MS analysis further confirmed EA formation and the presence of biodegradation products derived from geraniin and corilagin, indicating effective ET biotransformation. These findings establish optimized conditions for EA production from rambutan peel ETs via SSF and demonstrate the feasibility of implementing a sustainable bioprocess for the valorization of this agro-industrial residue.

Aim: This study aimed to analyze the entrapment processes of polyphenols using sodium alginate and gelatin for the development of potential food supplements and to evaluate biological properties. Methods: Entrapment beads containing pomegranate peel polyphenols were prepared by ionic gelation with sodium alginate and calcium chloride to achieve the optimal concentrations, while the gelatin gums were made artisanally according to the manufacturer’s recipe. To characterize the supplements, total polyphenol content, entrapment efficiency, antioxidant capacity, and prebiotic, antimicrobial, and hemolytic activities were assessed. Results: After the entrapment processes, the polyphenol content was 22.03 ± 0.39 mg/L for alginate beads and 67.00 ± 0.76 mg/L for gums, with entrapment efficiencies of 2.20% and 6.70%, respectively. Regarding biological activities, the antioxidant activity was 77.92% acid 2,2-azino-bis(3-etilbenzotiazolina-6-sulfónico) (ABTS) and 50.06% 1,1-diphenyl-2-picrylhydrazyl (DPPH) for alginate beads, and 39.66% for ABTS and 22.60% DPPH for gums. For prebiotic activity, gums with polyphenols favored the growth of Levilactobacillus brevis (4.10 × 109 cells/mL) and Lacticaseibacillus paracasei (2.49 × 109 cells/mL) strains. Conclusions: These findings suggest that it is possible to develop food supplements with biological properties using naturally occurring bioactive compounds from non-conventional sources through entrapment processes, although process optimization is necessary.