Carotenoids can offer numerous health benefits when consumed consistently (Table 4). Nevertheless, for this purpose, there must be a first release from the food matrix followed by carotenoid diffusion into oil droplets. The bile salts help to create micelles to assist the digestion of lipid forms, converting them in free fatty acids, mono- and diacylglycerides, lysophospholipids, and free cholesterol [48]. The harsh conditions throughout the absorption and assimilation process might conduct lycopene degradation due to exposure to pH changes, increased temperature, and oxidation [49]. Consequently, bio-availability and absorption are much lower than water-soluble molecules [50].

Strategies have been created to control problems related to the practical application of lycopene, which is strongly restricted due to its high sensitivity when exposed to light, oxygen, and heat, as well as contact with metal ions, besides processing conditions and low water solubility [11,51].

Encapsulation is one of the techniques that frequently uses oligosaccharides, such as cyclodextrins, to associate compounds in a hydrophobic core, while on the outside it forms a hydrophilic shell. The encapsulation protects lycopene from degradation and isomerization besides increasing its solubility in aqueous environments [51]. A report on the lycopene/α- and β-CD complexes pointed that both could provide stable associations in water with profound differences in structure [66]. Maltodextrins were used during tomato processing to powders aiming to increase lycopene stability [67].

Respective delivery systems have been created to enhance lycopene bio-availability and absorption rates (Figure 1) in the gastrointestinal environment [57,68]. During digestion, carotenoids are assimilated with other lipids into mixed micelles containing bile salts and phospholipids, which perform as carriers to solubilize the carotenoids and transport them to the zone of maximum absorption in the intestine. Incorporating lycopene into the oil phase of emulsions is an alternative to protect it from oxidation and chemical degradation, providing better bio-availability and prolonging shelf-life [48]. Nano-emulsions have been reported to be suitable delivery systems with favorable results for the encapsulation of low-solubility compounds, such as lycopene [51]. Recent works have shown efficient delivery systems for lycopene: its incorporation in oil-in-water emulsions for orange beverages [69], lycopene encapsulated in isolate-Xylo-oligosaccharide protein conjugates made by Maillard reaction [68], and oil-in-water emulsions with long- to short-chain triglycerides [57]. The literature also reports the formation of liposomes and nanoliposomes, which are spherical vesicles created with a concentric phospholipid bilayer of hydrophilic center. It was reported that lycopene tends to be entrapped in the hydrophobic bilayer, enhancing bio-accessibility when exposed to the gastrointestinal tract and with increased antioxidant capacity compared with the free form [70,71].

Oil–water nano-emulsions are nanoparticles dispersed in heterogeneous systems with an inner lipidic and an external aqueous phase stabilized by one or two surfactants. Unlike the nano-emulsions, lipid nanoparticles have an internal solid lipid phase since these nanoparticles are totally or mainly composed of solid lipids at room temperature. Such a solid matrix allows the controlled release of the encapsulated molecules and protects them from degradation while increasing the long-term stability of the system [72]. Lycopene-loaded SLNs demonstrated stability in an aqueous medium for two months, producing an applicable system for future in vivo trials in nutraceutical industries [59]. The encapsulation in SLN showed an improvement in lycopene oral delivery, and an ex vivo assessment determined that this carotenoid had better permeation besides causing more cytotoxicity against breast cancer cells [62]. Lycopene loaded into nanostructured lipid carriers (NLC) composed of Eumulgin SG, orange wax, and rice bran oil, employing high pressure in homogenization process, showed chemical stability and delayed degradation when put into cold storage [73].

Moreover, lycopene nano-emulsions have provided more thermal stability for lycopene and significantly inhibited edema formation. For this reason, these nanoparticles may be considered to be a potential candidate for anti-inflammatory therapy [16]. Lipid-core nanocapsules of lycopene, in turn, optimized stability for 7 months at 5 °C storage, and improved its toxicity against breast cancer cells. The nanocapsules also inhibited the production of intracellular peroxyl radicals in human microglial cells and maintained the membrane integrity of erythrocytes, highlighting its potential to be employed in cancer treatment [12].

Lycopene encapsulated in polymeric nanoparticles showed high anti-tumor potential, with cytotoxicity against cancer cells at low concentrations and no toxicity against Galleria mellonella. Additionally, nanoparticles with sizes of 162.10 ± 3.21 nm were efficient with a passive mechanism of permeability for targeting tumor tissues [11].

On the other hand, lycopene powder produced by complex coacervation and freeze-drying after microencapsulation had promising results as a biopolymeric composite with inhibitory effect potential on α-amylase associated with metabolic syndrome, and demonstrated high antioxidant activity in formulations [3].