Conditions of the Stepwise Cooling Algorithm for Stable Supercooling Preservation and Freshness of Pork Loin

Supercooling has the advantage of maintaining the freshness of foods without a phase transition. However, it is hard to sustain the supercooled state. Static temperature control, one of the various supercooling technologies, is used for stable supercooling storage. In this experiment, the effect of following external factors in maintaining the supercooled state of foods was investigated. Three main parameters had an effect on the supercooled state of food: (1) properly setting the lower-temperature limit of the supercooling algorithm, (2) slow cooling to the target temperature, and (3) minimizing temperature fluctuation. Accordingly, the following stepwise cooling algorithm for pork loin was designed: a lower-temperature limit of −3.0 °C and a storage period = 36 h followed by a lower-temperature limit of −3.5 °C for 24 h. The samples conserved at −3.0 °C displayed a 100% supercooled state. Physicochemical properties including drip loss, cooking loss, texture, color, total volatile basic nitrogen (TVBN), and total aerobic count (TAC) of pork loin were analyzed. The drip loss values of the supercooled meat samples were lower than those of the superchilled ones. Furthermore, TVBN and TAC of the treated samples were not significantly different from those of the fresh samples (p > 0.05). In conclusion, supercooling storage extended the freshness and quality of pork loin better than refrigerated storage.