Combining eutectic solvents and pressurized liquid extraction coupled in-line with solid-phase extraction to recover, purify and stabilize anthocyanins from Brazilian berry waste

Pressurized techniques are straightforward for high-scale applications and highly controllable, which seems an excellent strategy for recovering unstable natural compounds. In this work, the main advance was the development of a platform based on the pressurized liquid extraction coupled in-line with a solid-phase extraction step (PLE-SPE) combined with the use of eutectic mixtures as solvents to promote an efficient extraction and purification of natural pigments from food wastes. Eutectic mixtures, conventionally known as (deep) eutectic solvents – (D)ES, are combinations of two or more substances with a lower melting point than any of their components. (D)ES are often referred as “green solvents” because they can potentially be more environmentally friendly than other solvents, especially volatile organic solvents (VOSs). Overall, (D)ES have the potential to contribute to the achievement of several of the SDGs (especially 3, 13, and 14) through their positive impacts on health, environment, and sustainable production and consumption practices. Thus, in this work, (D)ES were used as solvents to valorize Brazilian berry waste (Plinia cauliflora). Anthocyanins are the biomass's main compounds of commercial interest, mainly for food and cosmetic applications. However, there are several technological issues regarding color control due to their high sensitivity to light, heat, oxygen, and pH variations. Thus, the data achieved in this work highlighted the high efficiency and low environmental footprint of the PLE-SPE-(D)ES platform developed. The success of the downstream process here developed was proved by the high extraction efficiency and the purity level of the anthocyanins obtained. Besides, thermal stability analysis was evaluated, demonstrating that (D)ES are not only solvents but also stabilizing agents, improving the shelf-life of the extracted colorants.publishe

Recent progress on the recovery of bioactive compounds obtained from propolis as a natural resource: processes, and applications

Propolis is a functional food ingredient classified by its physical–chemical characteristics, vegetal source, bee species, and geographical origin. Due to its complex nature and variable composition, the massive use of propolis extracts would require standardization. Several techniques for recovering bioactive compounds from propolis have been reported, varying according to their complexity, degree of automation, and energy dependence. The recovery of propolis target compounds must be carried out using the most appropriate extraction process and the optimized conditions, guaranteeing a better use of the raw material, lower process costs, and good extraction selectivity. This work presents and discusses conventional and alternative techniques developed in the last 20 years. The extraction efficiency, selectivity, the type and amount of solvent, and the conditions to optimize and guarantee safe products (e.g., toxicity and biocompatibility) were reviewed. The current trends were reported, and the technological advances, future perspectives, and applications of the natural bioactive compounds obtained from propolis were discussed. A comprehensive determination of the main advantages and disadvantages of the extraction techniques and the impact of operational conditions on the processes’ performance was assessed. Based on the available evidence, some future strategies will be scrutinized, not only regarding the future of using propolis and its products but also considering the impact of a propolis-business model crossing the concept of a circular economy and combining it with the idea of resource efficiency.publishe

Combining eutectic solvents and food-grade silica to recover and stabilize anthocyanins from grape pomace

Concentrated in the skins of red grapes are the anthocyanins, the primary colorants responsible for the fruits' reddish-purple color. These colorants are recognized for their significant antioxidant properties and potent nutraceutical and pharmaceutical ingredients. Nevertheless, their widespread use is compromised by the (i) need for more efficient yet sustainable downstream processes for their recovery and (ii) by the challenges imposed by their poor stability. In this work, these drawbacks were overcome by applying eutectic solvents and stabilizing agents. Besides, the anthocyanins were successfully loaded into a solid host material (approved in both food and pharmaceutical sectors) based on silicon dioxide (SiO2, loading capacity: 1extract:7silica m/m). Summing up, with the process developed, the extraction yield (21 mganthocyanins.gbiomass-1) and the stability (under 55, 75, and 95 °C) of the recovered anthocyanins were over three times better than with the conventional process. Finally, the raw materials and solvents were recycled, allowing an economical and environmentally friendly downstream process.publishe