Influence of ultrasound assisted extraction on the molecular, rheological and technological characteristics of actomyosin

Efficient use of by-products can reduce environmental pollution and increase the added value of the meat industry. Protein-rich by-products, including bones or tendon fragments, can be an excellent source of protein such as actomyosin (AM), used in food production. AM is a valuable protein in terms of technology and nutrition. In this work, attention was paid to checking the effect of the use of ultrasound (US) on the improvement of extraction efficiency and the influence of the ultrasonic process on the technological and rheological properties of AM. AM protein was obtained by washing turkey meat with a high content of connective tissue, KCl, and K-phosphate buffer pH 7.0 twice, with modifications in the form of ultrasound. Actomyosin was obtained in buffers of different salt compositions and ionic strength. The resulting solutions were analysed for protein content, and protein recovery; tested using dynamic oscillatory thermorheology to determine the modulus G' and G". The particles were examined by Fourier Transform Infrared spectroscopy (FTIR) and the molecular weight by high-performance liquid chromatography (HPLC analysis using polarized light, refractometric and viscometric detectors. Actomyosin gels were also prepared and tested for their ability to water-holding capacity. Ultrasonic modifications of the AM protein recovery process increase yield by up to 33%. Studies of dynamic oscillatory thermorheology, storage modulus G' and loss modulus G", demonstrate that the actomyosin denaturation process occurs at higher temperatures in ultrasound treated samples. It has been also found that the ultrasonic process has a positive impact on the water-holding capacity of AM gels, this could be the basis for the application of this method in the industry.