Binding of aroma compounds by isolated myofibrillar proteins: Effect of protein concentration and conformation

Actomyosin and G-actin were isolated from post-rigor porcine muscle and used to study their binding ability with selected volatile aroma compounds (3-methyl-butanal, 2-methyl-butanal, 2-pentanone, hexanal, methional and octanal). The binding ability was determined by measuring the headspace concentration of the volatile compounds in the presence of each protein using solid-phase microextraction (SPME) and gas chromatography analysis. Actomyosin was able to bind to all the assayed volatile compounds, although the binding was dependent on protein concentration and conformation, and highly affected by frozen storage. On the other hand, G-actin was unable to bind any of the assayed volatile compounds and furthermore, it caused the release of several of them (3-methyl-butanal, hexanal, methional and octanal) at the highest protein concentration. However, the polymerized form (F-actin) was the isolated myofibrillar protein that was able to bind higher quantities of the assayed volatile compounds.