## 4 Discussion
### Yield, Warner-Batzler Shear Force (WBSF), and Sensory Quality  
The free water content, thawing loss, and cooking yield were affected by the muscle type. The SM muscle had a lower IMF content and higher free water content. In lean muscles, most water molecules are distributed between the actin and myosin filaments in sarcomeres. Technological processes such as ageing, freezing, and cooking degrade the bonds between these proteins and push cell fluids into extracellular space [14]. The above could explain the significantly lower yields and higher cooking losses in the SM muscle compared with the LL, which were also noted in our previous studies [28; 35]. Similar cooking losses during SV were reported by other authors (approximately 21%) [6; 17]. In the work of [PERSON] et al. [31], the SV losses were lower (15-18%) in beef ribs subjected to SV at 60 \({}^{\circ}\)C for 12 h and 36 h. [PERSON] et al. [55] analysed the effect of the grilling temperature on the quality of aged ribeye, strip loin, and top sirloin steaks and reported a yield of 78.5%, which is similar to that noted for LL SVGrill (76%) in the present study. The cooking loss noted in the SVMar samples was similar to that reported in studies where acidic marinades were used. This parameter was estimated to be 29% in chicken breast muscles marinated for 48 h in marinades containing fermented beverages [56] and 30% and 37% in pork steaks marinated for 3 h and 12 h, respectively, in keifir, yogurt, and buttermilk [57]. The muscle specificity as well as the water and fat contents (in addition to pre- and post-mortem factors) are closely related to meat tenderness [54; 58]. Protein content is one of the key parameters that determines the nutritional value of lean meat and plays an important role in water binding and meat tenderisation [48]. In this study, the protein content was similar (22.5%) in the LL and SM muscles. However, the muscles differed in IMF content, which affected the WBSF values. The IMF content was higher, whereas the WBSF values were lower in the LL compared with the SM muscles, regardless of the applied treatment. Similar results were noted in our previous study [38], and they confirm the relationship between the fat content and tenderness, as observed by [PERSON] et al. [58]. Moreover, each additional technological treatment (marinating and grilling) decreased the WBSF values, where a significant decrease in this parameter (26.8% in LL and 20% in SM) was induced by marinating. A similar result was noted in our previous study, where commercial marinades increased the SM tenderness by 20% [28]. Other authors also reported that SV [6; 17] and marinating [59; 60] increased meat tenderness by decreasing the WBSF values. [PERSON] and [PERSON] [61] reported that the shear force was reduced by 24% in beef steaks subjected to blade tenderisation and marinated in lime juice and pineapple pure. In the work of [PERSON] et al. [36], the WBSF values were determined to be 39.4 N, 25.7 N, 49.0 N, and 42.1 N in beef marinated in blackberry, briar, grenade, and -grape vinegars. They concluded that meat marinated in briar vinegar was characterised by the highest tenderness and microbial safety. In this study, an attempt was made to identify the most effective methods for enhancing the aroma and taste of SV-treated beef. The influence of marinating and grilling on LL and SM quality was evaluated. According to some reports, the SV technique minimises the differences in the tenderness of meat products obtained from cattle of different sexes and slaughter ages, as well as meat that has been aged for different periods of time [17; 33]. This observation was confirmed in this study. The LL and SM muscles processed by SV were characterised by similar tenderness and juiciness as well as intensity of their aroma and taste. Marinating and grilling are commonly used to enhance the taste and aroma of meat products. Grilling involves three simultaneous chemical reactions which are responsible for the desirable aroma and taste of grilled meats.