This study pertains the encapsulation of bioactive compounds, specifically phenolic compounds and lycopene, extracted from olive and tomato by-products via oil-in-water (O/W) nanoemulsions and their potential application in functional beverages. The effect of various edible oils (olive pomace oil (OPO), sunflower oil (SFO), corn oil (CO), fish oil (FO), and canola oil (CLA)) in the lipid phase and antioxidants (ascorbic acid and phenolic extracts) in the aqueous phase on the physicochemical properties of oil-in-water (O/W) nanoemulsions enriched with lycopene was evaluated, along with the bioaccessibility of the encapsulated bioactive compounds using the static INFOGEST in vitro simulation protocol for gastrointestinal food digestion. All examined edible oils led to nanoemulsions with uniform droplet sizes (droplet size < 300 nm, droplet distribution < 0.3) and high stability during storage at 4 °C, with FO being the smallest, at 259.3 ± 9.1 nm, and OPO the largest, at 286.6 ± 10.0 nm. Ascorbic acid increased the droplet size by 5–8%, improved droplet distribution, and led to a lower deterioration rate (−0.014 d⁻¹) when compared to the “control” counterparts (−0.037 d⁻¹). Lycopene bioaccessibility was significantly affected by the lipid phase, with OPO exhibiting the highest percentage (53.8 ± 2.6%) and FO the lowest (40.1 ± 2.1%). The OPO nanoemulsion was selected for the development of a functional beverage, showing excellent long-term stability. The phenolic compound concentration remained consistent during storage, and the lycopene degradation rate was minimal, at −0.0088 d⁻¹, resulting in an estimated shelf life of 165 days at 4 °C, based on a 50% reduction in lycopene content. Similarly, phenolic compounds demonstrated high bioaccessibility, without a significant dependence on the lipid phase, and stability during shelf life, enhancing the beverage’s overall antioxidant profile. These results indicate that O/W nanoemulsions are effective delivery systems for functional beverages, offering improved stability and bioaccessibility of lycopene.

Endogenously formed N-nitroso compounds (NOCs) from nitrite use in red meat have been recently linked to the risk of colorectal cancer. Therefore, replacing sodium nitrite (E250) with natural antimicrobials, such as bioactive compounds, is an issue of great industrial and scientific interest. In this research, such compounds were extracted from rose petal (Rosa damascena) and rosemary leaf (Rosmarinus officinalis L.) by-products of the essential oil industry and appropriately introduced in commercial cured meat products, as partial nitrite replacers. Shelf-life tests demonstrated an inhibitory effect of the rose extracts on microbial growth, obtaining similar or reduced growth rates and a prolonged lag phase, when compared to conventionally produced samples (CNT): μ_max,ref = 0.128 vs. 0.166 d⁻¹ and λ_ref = 15.9 vs. 12.4 d at 4 °C, respectively. None of the bacon samples suffered from lipid oxidation in the examined period. The RSE samples (containing the rose extract and half of the nitrites) exhibited a good retention of their red color, receiving an acceptable sensory score throughout storage. Since the proposed partial nitrite replacement leads to an important shelf-life extension, namely 78 d (RSE) vs. 60 d (CNT), our results provide preliminary proof of the potential use and valorization of such side streams as effective natural antimicrobial agents for cured meat products, in order to reduce the use of nitrites.

Tomato processing residues—including peels, seeds, and pomace—are rich in bioactive compounds, such as lycopene, β-carotene, cutin, pectin, and antioxidants, yet are often underutilized. This study evaluates microwave-assisted extraction (MAE) and high-pressure-assisted extraction (HPAE) for the recovery of carotenoids from TP, compared to conventional extraction (CE) using ethyl acetate. Optimal MAE conditions (150 W, 50 °C, 20 min, solid/liquid ratio of 1:10 g/mL) yielded 592.5 mg carotenoids/kg dry weight (dw), exceeding CE yields (505.3 mg/kg dw), while significantly reducing extraction time (20 min vs. 120 min). By contrast, direct HPAE (650 MPa, ambient temperature, solid/liquid ratio of 1:10 g/mL) resulted in lower carotenoid yields (ca. 84 mg/kg dw), but when used as a pre-treatment followed by stirring for 24 h, HPAE enhanced carotenoids extractability to 277.0 mg/kg dw, recovering 55% of carotenoids extracted by CE. Bioaccessibility studies showed low lycopene bioaccessibility across all methods (3.9% for HPAE, 3.4% for MAE, and 1.6% for CE). Incorporation into oils significantly improved bioaccessibility, with olive pomace oil (OPO) achieving 28.1%, compared to 8.1% in corn oil (CO). Overall, MAE and HPAE (as pre-treatment) present efficient strategies that reduce solvent usage and processing time, though they still rely on organic solvents, while strategies to enhance bioaccessibility should further be explored for effective functional ingredient development.