Effect of meat particle size and different value cuts on the quality and ultrastructure of restructured mutton slices

• Meat particle size and cuts affect the quality of restructured mutton slices. • Key myofibrillar proteins involved in the binding of meat chunks were identified. • Deciphered the role of extractable proteins in the ultrastructural integrity. • Quality improvement was achieved using low-value cuts of small particle size. The impact of meat particle size and different value cuts was evaluated on the quality of restructured mutton slices (RMS). RMS were developed using meat of different particle sizes (T1 and T2 = 1.5 cm; T3 and T4 = 2.5 cm) and value cuts (T1 and T3 = 100% high-value cuts; T2 and T4 = 80% high-value cuts + 20% low-value cuts) through a hot-set binding system. The addition of low-value cuts and increasing the particle size negatively affected some of the quality parameters of RMS (such as batter stability, total protein extractability, collagen content, collagen solubility, water holding capacity (WHC), and cooking yield). The particle size and the meat cuts affected (P<0.05) the proximate composition, texture and instrumental colour [redness (a*) and lightness (L*)] of the products. Electrophoretic analysis of the T1 samples showed increased protein fragmentation within the molecular weight ranges of 35-48 kDa and 180-245 kDa. RMS samples prepared using 1.5 cm meat particles (notably T1) displayed a more homogeneous and regular microstructural arrangement, characterized by a denser protein network. Both particle size and type of meat cuts were found to differentially influence the sensory attributes of RMS, indicating a critical role in the product quality.