Interactive Effects of Freeze-Thaw Events and Endpoint Cooking Temperature on Water-Holding Capacity and Instrumental Tenderness of Pork Loins Cooked Using Sous Vide

The objective was to determine the interactive effect of freeze-thaw events and endpoint cooking temperature on instrumental tenderness and water-holding capacity of aged pork loins. Pork loins (n = 64) were randomly assigned to 4 aging/freezing treatments (A14-NF, aged 14 d and never frozen; A21-NF, aged 21 d and never frozen; A21-F1, aged 14 d followed by one freeze-thaw event and 7 additional d of aging; A21-F2: aged 14 d followed by one freeze-thaw event, 7 additional d of aging followed by a second freeze-thaw event). Each section was further fabricated into two 2.54-cm-thick pork chops and randomly allocated to an internal endpoint cooking temperature of either 63°C or 71°C using the sous vide cooking technique. Data were analyzed using a split-plot design with aging/freezing treatment as the whole-plot factor and endpoint cooking temperature as the sub-plot factor. Never-frozen pork chops (A14-NF and A21-NF) had lower (P < 0.05) purge loss compared with A21-F1 and A21-F2 pork chops. Significant interactions between aging/freezing treatments and endpoint cooking temperature were present for cooking loss and Warner-Bratzler shear force (WBSF). Treatment A14-NF exhibited the greatest (P < 0.05) cooking loss compared with other treatments within both respective endpoint cooking temperatures. Never-frozen pork chops (A14-NF and A21-NF) had greater (P < 0.05) WBSF values compared with A21-F1 and A21-F2 pork chops when cooked to an endpoint temperature of 71°C. However, when pork chops were cooked to an endpoint temperature of 63°C, similar WBSF values were observed for A21-NF and A21-F1 treatments, and lower (P < 0.05) WBSF values were observed for the A21-F2 treatment. Overall, freeze-thaw events increased purge loss and had limited effects on cooking loss and WBSF. The interactive effects for endpoint cooking temperature highlight the potential interplay and importance between freeze-thaw events and endpoint cooking temperature.