Assessment of the effect of marination with broccoli (Brassica oleracea var. italica) juice and balsamic vinegar on tenderness and quality of beefsteak

Due to the increasing demand for natural foods with fewer artificial additives, broccoli is considered by the consumers and researchers due to its taste, nutritional values and biochemical components. Therefore, this research was conducted to investigate the effect of broccoli juice and balsamic vinegar on the physicochemical and textural attributes of the beefsteak aimed at tenderizing it and decreasing the ageing period. Experiments were carried out through marinating the beefsteak with three different treatments containing 3.00 units protease g^-1 beefsteak of broccoli juice and 10.00% (v/w) of balsamic vinegar during 48 hr storage at 4.00˚C. A significant reduction in pH and Warner-Bratzler shear force as well as the increase in myofibrillar fragmentation index and myofibrillar protein solubility were obtained showing that the beefsteak was tendered in the presence of broccoli juice and broccoli juice+balsamic vinegar. Scanning electron microscopy images showed the destruction of endomysium collagen and sarcolemma areas of muscle filaments in the above-mentioned treatments. The electrophoretic analysis of isolated myofibrillar proteins indicated that the rate of troponin-T breakdown was quicker in all treatments compared to the control and its degradation was progressively obvious with 20.00 and 28.00 kDa protein bands in mentioned treatments. Based on the results, marinades of broccoli juice and balsamic vinegar could be utilized as a beneficial additive for improving beefsteak tenderness.