LAUSR

Vacuum cooling has notable advantages including fast cooling rate, cleanness, and high energy efficiency. However, the weight loss of food after being vacuum cooled was unsatisfactory, especially for meat products. Immersion vacuum cooling can significantly reduce the weight loss of food compared with traditional vacuum cooling procedures, but the cooling rate is unacceptable. To overcome this problem, here, a novel vacuum cooler, bubbling vacuum cooler, was designed and evaluated for the small-size cubic cooked pork with a side length of 1.5 cm from about 60 to 4 °C. Experimental results indicated that bubbling vacuum cooling can reduce the weight loss (about − 2.3%) of food compared to both vacuum cooling (about 12.4%) and immersion vacuum cooling (about 0.5%) (P < 0.05). Further, bubbling vacuum cooling can cool the sample with a slightly more rapid cooling rate (0.10 °C/s) contrasted with immersion vacuum cooling (0.07 °C/s) (P > 0.05). For the chromatism value of sample, no significant difference was found between immersion vacuum cooling and bubbling vacuum cooling (P > 0.05). The textural property of sample cooled by bubbling vacuum cooling was close to (for hardness, elasticity, chewiness, and shear force, P > 0.05) and better (for cohesiveness, P < 0.05) than that of immersion vacuum cooling. Thus, our experiment demonstrated that cooked pork cooled by bubbling vacuum cooling has a lower weight loss rate and a more rapid cooling rate than that of immersion cooling.