Valorization of Hot Trub: Extraction and Nanoparticle Encapsulation for Antitumor Applications

The brewing industry generates large amounts of waste containing bioactive compounds with potential applications in the pharmaceutical and cosmetic industries. This study optimized the extraction of bioactive compounds from hot trub using 70:30 (v/v) ethanol:water as the extraction solvent, with time and temperature optimized through an experimental design. The optimized extract exhibited high antioxidant activity and was rich in phenolic acids, flavonoids, and xanthohumol. The extract demonstrated promising photoprotective properties, with a sun protection factor of 13.84, suggesting its potential for dermocosmetic use. The extract was encapsulated in zein nanoparticles, including chitosan-coated and sodium caseinate-coated variants, to enhance stability, bioavailability, and bioactivity. The effect of the encapsulated extract on cell viability was evaluated against the MCF-7 breast cancer cell line. Results indicated that encapsulation in zein nanoparticles improved the in vitro effect of the extract on MCF-7 cell viability, with chitosan and sodium caseinate coatings enhancing this effect. These findings highlight hot trub as a sustainable source of bioactive compounds with potential for dermocosmetic applications and as a basis for further investigation in cancer research. Future studies should focus on evaluating the long-term stability of the nanoparticles and on assessing their biological activity in more complex models.