Abstract: In this paper, the effects of vacuum treatment combined with soybean protein isolate (SPI)-based composite cryoprotectant on the moisture distribution, freezeable water content and microstructure of quick-frozen dumpling stuffing were studied. The results showed that 60 min vacuum treatment combined with the cryoprotectant had the best effect on improving various indicators of meat stuffing during frozen storage. On day 90 of frozen storage, the thawing loss rate and thiobarbituric acid reactive substances (TBARS) value of the combined treatment group decreased by 61.3% and 85.8% compared with those of the control group without any treatment; by only 39.3% and 3.3% compared with those of the single cryoprotectant treatment group, respectively. The combined treatment significantly improved the hardness, elasticity, chewiness and cohesiveness of meat stuffing, and increased the content of weakly bound water of 16.1% and 2.4% compared with the control and single cryoprotectant treatment groups, respectively. The combined treatment reduced the size of ice crystals in frozen meat stuffing, the length of most ice crystals being less than 10 μm in this treatment group, and protected the microstrcuture of meat stuffing from damage during frozen storage. In conclusion, the combined treatment could improve the water-holding capacity and texture of meat stuffing, delay fat oxidation, and protect the microstrcuture of meat stuffing from damage during frozen storage, thereby improving the quality of quick-frozen dumpling stuffing.

Key words: meat stuffing quality; soybean protein isolate; vacuum treatment; moisture distribution; microstructure