An innovative method of vacuum cooling for cooked pork meat: Uninterrupted operation between immersion vacuum cooling and vacuum cooling.

To address the challenges associated with cooling large, cooked meat products, we developed a novel cooling method: uninterrupted operation between immersion vacuum cooling and vacuum cooling (UO-IVC&VC) while comparing its performance with traditional methods, including air blast (AB), vacuum cooling (VC), and immersion vacuum cooling (IVC). Our results showed that UO-IVC&VC effectively integrated IVC and VC under isobaric conditions. The time required to reduce the core temperature from 72 to 4 °C with UO-IVC&VC was 59.9 min, longer than VC (44.4 min) but shorter than IVC (90.2 min) and AB (356.8 min) (p < 0.05). UO-IVC&VC significantly shortened the cooling time in the later phase (20-4 °C) to 29.5 min, which was slightly faster than VC (31.5 min) (p > 0.05). The weight loss rate for UO-IVC&VC-treated sample was 3.81 %, lower than that of AB (4.32 %) (p > 0.05) and VC (9.23 %) (p < 0.05), but slightly higher than IVC (3.36 %) (p > 0.05). The color coordinates (a*, L*), relaxation time T24, and texture (Warner-Bratzler shear force, Hardness, Gumminess and Chewiness) of UO-IVC&VC-treated sample were intermediate between VC and IVC, which improved color and quality. Additionally, UO-IVC&VC, IVC, and AB treatments resulted in uniform moisture distribution, while VC, IVC, and UO-IVC&VC exhibited slightly more disordered muscle fiber structures compared to AB. In conclusion, UO-IVC&VC demonstrates potential for effective application in the cooling of large, cooked meat products.