Effect of Different Storage-Temperature Combinations on Longissimus dorsi Quality upon Sous-vide Processing of Frozen/Thawed Pork

This study investigated the effect of storage state (chilled state on sous-vide, CS; frozen state without thawing on sous-vide, FS; and frozen/thawed states on sous-vide, TS) and sous-vide cooking temperature ($65^{\circ}C$ and $72^{\circ}C$) on the longissimus dorsi muscle quality of pork. FS showed a higher moisture content than that of CS and TS (p<0.001), whereas both FS and CS showed higher expressible moisture loss than that of TS (p<0.001). FS showed a lower cooking loss (p<0.001) than that of CS and TS. FS and TS exhibited significantly higher lipid oxidation than that of CS. Carbonyl and sulfhydryl content were not significantly affected by the storage treatment. FS and TS exhibited lower shear force than that of CS (p<0.001). FS and TS showed higher springiness than that of CS (p<0.001), FS exhibited lower gumminess than that of CS and TS (p<0.01). Sous-vide treatment at $65^{\circ}C$ exhibited significantly higher moisture content and lower expressible moisture loss, cooking loss, and total and sarcoplasmic protein than those at $72^{\circ}C$. Shear force and springiness of $65^{\circ}C$-treated groups were lower than those of $72^{\circ}C$-treated groups (p<0.01). Cooking temperature significantly influenced overall acceptability, whereas the storage state did not affect the overall acceptability. These results indicated that meat quality might be improved upon cooking from the frozen or frozen/thawed state using sous-vide when compared with traditional processing.