The objective of this paper is on the one hand to study the effect of heat processing (30 to 130°C for 2 h) on the stability and antioxidant activity of six flavonoids (rutin, naringin, eriodictyol, mesquitol, luteolin, and luteolin 7‐O glucoside), and on the other hand to establish the relation structure–activity–stability of these compounds. The dependency on temperature of the six kinetics was well described by the Arrhenius law and the main parameters provided by this model are determined and compared in this paper. Activation energies found were 107.3 kJ/mol for rutin, 100.6 for naringin, 33.3 for mesquitol, 68.2 for eriodictyol, 51.4 for luteolin, and 120 for luteolin 7‐O‐glucoside. The data collected showed that glycosylated flavonoids are more resistant than aglycon flavonoids to heat treatment. Moreover, it was also observed that despite the total degradation of some flavonoids, the treated solutions still have an antioxidant activity. Practical application Flavonoids are mainly consumed in processed foods. Thus, flavonoids often undergo heat processing. Knowing the thermal stability and the evolution of their antioxidant activity are particularly relevant in the field of food processing. The results of this study allow information to be collected on the relationship between heat stability‐flavonoid structure and antioxidant activity. This information will be useful for the formulation of new food products or for the design of new food processes.

In this study, we carried out simulations at the molecular and mesoscale (MesoDyn and DPD) levels in order to identify the main groups implicated in the solubility and the dispersion of flavonoids in several solvents. The results of the simulation are compared here to the experimental ones (kinetics of solubilization and microscopic observation). The obtained results showed that the Flory−Huggins interaction parameter can help to select the best solvents for the flavonoids solubility. In the three studied flavonoids, the B2 part interacts positively with tert-amyl alcohol, propanol, and isopropanol (χ ij near to 0.5). The g(r) values of B2−tert-amyl alcohol bead pairs are higher and thinner than those of B2−acetonitrile, which implies that the adjacent interactions between B2 and tertamyl alcohol are stronger than those between B2 and acetonitrile. The order parameter of the beads shows phase separation in the case of the quercetin/tert-amyl alcohol system, indicating that quercetin aggregates in tert-amyl alcohol. Molecular and mesoscale modeling simulations corroborate the experimental findings.

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To understand the nanoparticle formation of quercetin in the poly-lactic-co-glycolic acid/water system, a multiscale approach combining experimental, molecular, and mesoscale modelings was carried out. The evolution of interactions occurring between compounds mixed at different ratios was evaluated by the order parameter, calculated using MesoDyn simulations. The obtained results indicated that the studied systems allowed to produce spherical nanoparticles well distributed in the continuous medium (water). The fast kinetics of nanoparticle formation is reached with 10 g L–1 of poly-lactic-co-glycolic acid, 0.5 g L–1 of quercetin, and 0.5% of polyvinyl alcohol. The corresponding order parameter of water (P water) was equal to 0.018. The increase of poly-lactic-co-glycolic acid and quercetin concentrations and the lactic acid content in poly-lactic-co-glycolic acid favor the formation of nanoparticles with a large size. The formed nanoparticles were composed of quercetin in the center of the system, poly-lactic-co-glycolic acid, as the second layer, and polyvinyl alcohol as the third layer. The water is the continuous phase. The shape, the size, and the order organization of nanoparticles were checked experimentally using transmission electron microscopy and dynamic light scattering. The obtained results indicated that experimental investigations are in good agreement with the simulated ones. Therefore, computational mesoscopic modeling can be used as a successful tool to predict the behavior of quercetin/poly-lactic-co-glycolic acid/water systems under different operating conditions.