Physicochemical, microstructural, and sensory attributes of frozen Buffalo loins treated with sodium tripolyphosphate and sous-vide cooking

This study investigates the effects of sous-vide cooking with varying concentrations of sodium tripolyphosphate (STPP) on the physicochemical properties (pH, cooking loss, water-holding capacity, colour properties, and shear force), lipid oxidation (thiobarbituric acid reactive substances, TBARS), secondary protein structures (Fourier transform infrared, FTIR), microstructure (scanning electron microscope, SEM), and sensory attributes (descriptive analysis) of frozen buffalo loins. Commercial buffalo loins (Black Gold) imported from India were used as samples (n = 15). They were sliced into steaks of 2 cm thickness, injected with 0 %, 0.15 %, and 0.3 % STPP, vacuum-sealed, and tumbled at 4 °C for 1 h. Subsequently, they were cooked sous-vide at 60 °C for 6 h. Results indicated that STPP significantly increased pH, reduced cooking loss, and enhanced water-holding capacity. Higher STPP concentrations increased lightness and redness while lowering shear force values. TBARS reached 2 mg MDA/kg in the 0 % STPP group by day 7, while buffalo loins with 0.15 % and 0.3 % STPP reached this level by days 21 and 28, respectively. FTIR showed similar secondary protein structure patterns in buffalo loins with 0.15 % and 0.3 % STPP, while the untreated sample had irregular patterns. SEM analysis revealed porous muscle fibres and thinner perimysium in the 0.3 % STPP samples, indicating greater tenderness. Sensory evaluation confirmed improvement in visual appeal, juiciness and aroma with 0.3 % STPP concentration.