INFLUENCE OF CARCASS VASCULAR RINSING WITH CALCIUM CHLORIDE ON NON-ELECTRICALLY STIMULATED AND STIMULATED CARCASSES ON MEAT QUALITY OF LAMBS

Abstract

Infusing calcium chloride into carcasses before rigor mortis presents a promising avenue for enhancing meat quality and tenderness. This technique targets the activation of µ-calpain and m-calpain, two key enzymes responsible for the postmortem breakdown of myofibrillar and cytoskeletal proteins (Huff Lonergan et al., 2010). The effectiveness of intra-arterial infusion of lambs with a 0.3 M solution of CaCl2 (10% live weight) was previously demonstrated, resulting in reduced shear force across varying postmortem intervals 1, 7, 14 days (Koohmaraie et al., 1991). The emergence of Rinse & Chill® technology (MPSC Inc., Hudson, United States) has further facilitated the commercial viability of calcium chloride infusion into carcasses, fostering opportunities for continued exploration and application of such methods (Hwang et al., 2022). This study aimed to assess the impact of calcium chloride infusion into lamb carcasses on pH decline, meat color and Warner-Bratzler shear force (WBS). It was hypothesized that the infusion of calcium chloride would lead to a reduction in shear force, thereby contributing to increased meat tenderness. The study was conducted over three different trial periods with lambs (n=40) which consisted of various breeds (commercial crossbred, Dorset, Hampshire, Suffolk, Polypay, Southdown), age (6-9 months), and live body weight (59.4 ±29.5 kg). Lambs were randomly

assigned to three vascular rinse treatments (TRT) that included: (RC= Rinse & Chill® solution; saccharides, phosphates), (CA= 0.3M CaCl2 + RC), (ES-CA= electrical stimulation, 800mA current, peak 350V for two consecutive 30-second applications, followed by CA). Animals were stunned by penetrating captive bolt. The vascular rinsing process entailed inserting a catheter into the heart and rinsing the carcass at 10% of its body weight. Treatments were applied to the carcass immediately upon exsanguination. Carcasses were skinned, eviscerated, and chilled (3℃, 24 h). Carcass temperature and pH were recorded (semimembranosus, SM) from 1 to 20 h postmortem (PM). At 24 h PM, the longissimus dorsi (LD), SM, and triceps brachii (TB) were excised, vacuum packaged, or overwrapped in oxygen-permeable film. Color measurements (CIE L*, CIE a*, chemical states of myoglobin) were determined during storage (3 and 7 d PM). Purge, (WBS) on cooked (68.3 ℃ internal) LD, SM, and TB chops, and cook loss (3 and 7 d PM) were determined. Concentrations of calcium and phosphorus in the muscles were analyzed. Data was analyzed as a split-split plot design with means (P<0.05) separated using PROC MIXED (SAS Institute). Live animal weights were not different (P>0.05) among the treatments. Hot carcass weights were not different (P>0.05) among the treatments. For carcass pH, the ES-CA treatment was lower (P<0.05) than the Ca and RC treatments, while CA was lower (P<0.05) than the RC treatment. The RC treatment had greater CIE L*, CIE a*, Chroma C, and oxymyoglobin, and lower values for metmyoglobin (P<0.05). The SM muscle had lower CIE L* (P<0.05) than the LD and TB muscles. At day 3 PM, CIE a* was lower (P<0.05) in the LD muscle compared to TB and SM. On day 7 PM, CIE a* was higher (P<0.05) in the TB muscle compared to LD and SM. RC had the least (P<0.05) purge in the LD and SM muscles. RC had lower (P<0.05) cook loss than ES-CA. The LD in CA and ES-CA had lower (P<0.05) WBS than RC. With ES-CA, the SM

exhibited the lowest (P<0.05) WBS. RC had the greatest WBS at day 3 (P<0.05), with no differences (P>0.05) found among TRT on day 7. In the LD muscle, calcium had a lower (P<0.05) concentration in the RC treatment than CA and ES-CA. In the TB muscle, there was a lower (P<0.05) concentration of calcium in RC than in ES-Ca. In the SM muscle, calcium had a lower (P<0.05) concentration in the RC treatment than Ca and ES-Ca. No treatment differences were found in phosphorous concentrations. The SM muscle had greater (P<0.05) phosphorous concentrations than the LD and TB. The LD had higher (P<0.05) phosphorous concentrations than the TB muscle. The implications of vascularly delivering calcium chloride throughout the carcass on meat quality are noteworthy, particularly shear force reduction, suggesting the potential to enhance tenderness. More rapid chilling to reduce the effect of the rapid drop in pH may benefit meat color and moisture retention.