The sous-vide technique (SV) enables precise control of time and temperature during thermal treatment and has recently been extended to sequential or multi-step protocols. This Master’s thesis investigated the effects of single-step (SV1: 10 h/60 °C) and two-step (SV2: 3 h/45 °C + 7 h/60 °C) sous-vide processing on the quality of bovine Triceps brachii (TB), a muscle rich in collagen, in comparison with in meat science reference Longissimus dorsi (LD) muscle, which contains less collagen. Physicochemical traits (cooking loss, pH, proximate composition), instrumental measurements of texture (share force, TA.XT Plus® Texture Analyser) and colour (L*a*b*, Minolta chromameter), lipid oxidation (TBARs, spectrophotometry), myofibrillar fragmentation index (MFI), amino acids and collagen content (total and released; LC-MS/MS) were determined. Sensory evaluation (descriptive analysis) complemented the instrumental analyses, and statistical significance was assessed by using analysis of variance (ANOVA). Two-step processing (SV2) did not reduce cooking loss, improve water-holding capacity, or result in a statistically significant increase in tenderness compared with single-step processing (SV1). Although instrumental measurements suggested that TB was more tender than LD, sensory evaluation consistently rated TB as tougher, indicating inconsistency between perceived and measured texture. The total collagen content of TB was approximately four times higher than that of LD, whereas its released fraction was lower, suggesting greater thermal stability of collagen in TB. Furthermore, processing regime had no significant effect on lipid oxidation (TBARs) or proteolysis (MFI). The results suggest that more effective tenderization of collagen-rich beef muscles may require longer cooking times or the integration of complementary processing techniques.
|
