Background. Gluten-free binary gels (BGs) composed of polysaccharides and animal proteins appear to be food products of great practical importance due to the constantly increasing risk of coeliac disease. Moreover, understanding the factors influencing the stability of aroma compounds (ACs) is very important because consumer acceptance of food is mainly dependent on aroma. The objective of this research was to determine the thermodynamic and kinetic behavior of ACs in BGs prepared with starches varying in amylose content depending on the concentration of myofibrillar proteins (MPs). BGs were prepared with 8 % of waxy rice starch (WRS) or tapioca starch (TS) and MPs ranged from 2 to 12 %. BGs were aromatized with: 1-heptanol, nonanal, 2-butanone, ethyl acetate, s-(+)-carvone. The studies included measurements of: rheological properties of BGs, non-covalent interactions between myosin and ACs, retention and release of ACs and enthalpy of ACs vaporization (ΔH_vap).
Results and conclusions. The main non-covalent interactions between myosin and ACs were hydrogen bonds and hydrophobic interactions. Retention and release parameters, determined during refrigerated storage (12 days) were statistically significantly (p ≤ 0.05) dependent on: starch type, MPs concentration and physicochemical properties of ACs. The ACs release rate constants were statistically significantly (p ≤ 0.05) correlated with those of rheological parameters derived from first order kinetic equation. ΔHvap values found in TS-based BGs were generally lower (p ≤ 0.05) than in counterparts prepared using WRS. BGs with a relatively high protein content can be intended for direct consumption and as subsystems for other food products to increase ACs stability.