Peppermint essential oil is encapsulated by inverse ionotropic gelation in core–shell systems, composed of alginate (ALG) alone or alginate with shellac gum (SHL) and/or carrageenan (CRG). A mixture design approach is used to evaluate the correlation between the formulation composition and some properties of the final products. Immediately after the preparation, capsules appear rounded with a smooth and homogeneous surface, having a similar particle size ranging from 3.8 mm to 4.5 mm. The drying process, carried out at 40 °C in an oven for 3 h, reduces capsules’ diameters by at least 50% and has a negative impact on the shape of the systems because they lose their regular shape and their external membrane partially collapses. The peppermint essential oil content of dried capsules is between 14.84% and 33.75%. The swelling behaviour of the systems is affected by the composition of their outer shell. When the external membrane is composed of alginate and shellac gum, the capsule ability to swell is lower than that of the systems containing alginate alone. The swelling ratio reaches 31% for alginate capsules but does not exceed 21% if shellac is present. Differently, when the second polymer of the shell is carrageenan, the swelling ability increases as a function of polymer concentration and the swelling ratio reaches 360%. In the case of systems whose outer membrane is a polymeric ternary mixture, the swelling capacity increases or decreases according to the concentrations of the individual polymers. The obtained results suggest that carrageenan could be a useful excipient to increase the swelling behaviour of the systems, while shellac gum makes the system shell more hydrophobic. The use of a mixture design (i.e., the use of ternary diagrams and related calculations), in which each single component is chosen to provide specific properties to the final mixture, could be the right approach to develop improved formulations with a tailored essential oil release profile.

Spray congealing technique was exploited to produce solid lipid microparticles (SLMp) loaded with a highly water-soluble drug (metoclopramide hydrochloride) dissolved in the aqueous phase of a water in oil (W/O) emulsion. The use of an emulsion as starting material for a spray congealing treatment is not so frequent. Moreover, for this application, a W/O emulsion with a drug dissolved in water is a totally novel path. A ternary diagram was built to optimize the emulsion composition, a factorial design was used to identify the factors affecting the properties of the microparticles and a Design of Experiment strategy was applied to define the impact of process conditions and formulation variables on the SLMp properties. SLMp were characterized by particle size distribution, morphology, residual moisture, drug content, release behavior, FT-IR analysis and XRPD. The obtained microparticles presented a spherical shape, particle size distribution between 54–98 µm depending on atomizing pressure used during the production step and 2–5% residual moisture 4 days after the preparation. XRPD analysis revealed that lipid polymorphic transition alfa-beta occurs depending on the presence of water. In vitro drug release tests highlighted that all the formulations had a reduced release rate compared to the drug alone. These results suggest that spray congealing of a W/O emulsion could be proposed as a good strategy to obtain SLMp with a high loading of a hydrophilic drug and able to control its release rate.

The ionotropic gelation technique was chosen to produce vitamin D3-loaded microparticles starting from oil-in-water (O/W) Pickering emulsion stabilized by flaxseed flour: the hydrophobic phase was a solution of vitamin D3 in a blend of vegetable oils (ω6:ω3, 4:1) composed of extra virgin olive oil (90%) and hemp oil (10%); the hydrophilic phase was a sodium alginate aqueous solution. The most adequate emulsion was selected carrying out a preliminary study on five placebo formulations which differed in the qualitative and quantitative polymeric composition (concentration and type of alginate selected). Vitamin D3-loaded microparticles in the dried state had a particle size of about 1 mm, 6% of residual water content and excellent flowability thanks to their rounded shape and smooth surface. The polymeric structure of microparticles demonstrated to preserve the vegetable oil blend from oxidation and the integrity of vitamin D3, confirming this product as an innovative ingredient for pharmaceutical and food/nutraceutical purposes.

Spray drying is a practical solution to convert oil in water emulsion into solid microparticles. In this work, a formulation study was conducted to identify the best composition of vitamin D3 loaded oil-in-water emulsion to process via a lab-scale spray dryer. The emulsion was composed of vitamin D3 oily solution (7 % w/w) and maltodextrin (21 % w/w), arabic gum (9 % w/w) and pea protein hydrolysate (1 % w/w) aqueous solution and was characterized by optimal stability (> 24 h). The spray drying process (T_in: 160 °C; T_out: 94 °C; Gas atomization: 1.75 bar; Feeding rate: 8.75 g/min) was successful: the process yield was good, and the obtained powder had an acceptable residual humidity. The average diameter of microparticles was 23 µm with a quite wide particle size distribution. The oil and vitamin D3 recovered from the powder were 85.69 ± 3.91 % and 80.10 ± 9.94 % of the expected respectively. The accelerated stability and photostability study results showed that the percentage of vitamin D3 present in the powder after storage was twice compared to vitamin D3 in oil solution stored at the same conditions. Moreover, the scale-up of the process from lab- to pilot-scale spray dryer was encouraging. Regardless of the top or bottom spray set-up, the pilot scale treatments increased the production rate and improved drying efficiency. The top spray configuration and a low inlet temperature guaranteed a yield of over 86 %, about 3 % residual humidity in the powder, and preserved the oil quality, maintaining a peroxide value comparable to the initial one.

Artemisia absinthium L. is a medicinal plant well known for the bitterness of its sesquiterpenoids. To mask its intense taste while preserving these active compounds, an ethanolic extract (AAE) was prepared, and two microencapsulation techniques (spray drying and ionotropic gelation) were investigated under different process conditions. The best-performing formulation was selected for larger-scale production and a characterisation of the microparticles (MPs) was carried out. MPs were then incorporated into baked products (biscuits), which were subsequently characterised for proximate composition, total phenolic content (TPC) and antioxidant activity (AA). Bitter compounds were quantified through HPLC-DAD. A panel test was conducted on 50 volunteers, which compiled a satisfactory questionnaire. Ionotropic gelation proved to be the most suitable technique for producing AAE alginate-based MPs for incorporation into biscuit dough, yielding a product with a desirable particle size and flowability. The biscuits still retained a significant amount of TPC and AA, indicating that microencapsulation is a suitable strategy. Data from the acceptance questionnaire revealed that biscuits containing MPs loaded with absinthin-rich extract were comparable to the control ones regarding overall acceptance. In conclusion, a promising product was developed that effectively masks the bitterness of appetite-modulating bioactive compounds, with significant health-promoting potential. However, further investigation into the biological effects (e.g., hormonal responses, feelings of hunger, etc.) of these baked products is required.

The valorization of agri-food by-products generated during juice extraction represents a key strategy within circular economy frameworks, as it reduces the environmental impact of waste disposal while creating added value and improving the food supply chain. In this work, five betaine-based natural deep eutectic solvents (NaDES) differing in their hydrogen-bond donors, namely citric acid, lactic acid, acetic acid, glycerol, and ethylene glycol, were used for the green extraction of blueberry pomace, a largely underutilized by-product that is nevertheless rich in bioactive compounds. The extracts were characterized by liquid chromatography coupled with diode-array and tandem mass spectrometric detection, allowing targeted profiling of anthocyanins and non-anthocyanin phenolics, including phenolic acids, flavonoids, and phenolic aldehydes. The extraction performance of NaDES was benchmarked against conventional solvents (water and ethanol) to evaluate differences in selectivity and efficiency toward distinct phenolic classes. Antioxidant capacity was determined using DPPH and ABTS radical scavenging assays. Among the NaDES systems, the betaine–citric acid NaDES extract exhibited notable phenolic recovery together with marked radical scavenging activity. After evaluating its inhibitory activity against elastase and tyrosinase, enzymes involved in the skin aging process, the selected NaDES extract was incorporated into a natural-based antiaging cosmetic formulation, and its main physicochemical properties were assessed to verify suitability for topical application. This study demonstrated that the use of NaDES represents an environmentally friendly and sustainable approach to transform blueberry by-products into high-value, safe, and ready-to-use cosmetic functional ingredients without the need for solvent removal.