Effect of polyphenol-hydrocolloids interaction on protein oxidation, structure and water distribution properties of thermally processed meat

In order to overcome the weakness and instability of polyphenols during thermal processing, the effect of various food additives including hydrocolloids combined with Gallic acids (GA) on structure, water distribution and oxidative properties of roasted meat was investigated. The findings publicized that the combined addition of GA with carrageenan (CAR) and sodium pyrophosphate (SPP) significantly (P < 0.05) decreased cooking loss, surface hydrophobicity, carbonyl formation and prevented the loss of sulfhydryl groups compared to alone GA and control. The fluorescence spectroscopy and FT-IR analysis showed that combination of GA with CAR and/or SPP decreased hydrophobic aggregation, prevented oxidation of side chain amino acids residues and developed GA-CAR/SPP non-fluorescent complexes with proteins. The inhibitory mechanism of G-CAR and G-SPP was predominated by retaining tightly bound water inside the macromolecules and prevented its seepage from the myofibrillar fiber network, which was also evidenced by high adhesiveness and gumminess of those samples. The microstructure endorsed the compact structure of those samples whereas uneven surface and intercellular spaces were noticed in control samples. Finally, correlation and principal component analysis further differentiated the most influential parameters and mechanism of action. These findings suggest that GA alone is not compatible for thermal processing until supported by an effective additive having potential of creating synergism to improve the thermal stability and quality characteristics of meat.