浓缩牦牛骨汤真空冷冻干燥工艺实验研究

以牦牛骨为原料,采用高压结合常压文火煮制工艺经真空减压浓缩生产浓缩牦牛骨汤,再经真空冷冻干燥技术制成具特色的速溶复合牛骨汤料产品,研究了预冻温度、真空度、冷冻干燥时间、物料厚度等因素对浓缩牦牛骨汤真空冷冻工艺的影响。采用单因素及正交实验,以干品率为依据,结合浓缩牛骨冻干汤料复水后感官质量评分筛选出最佳冻干工艺条件,即:物料厚度3mm、真空度20Pa、冷冻干燥时间6h、预冻温度-40℃。对浓缩牛骨真空冻干汤料产品复水冲调特性、微观表面形貌、风味成分分析结果表明,产品性能稳定,感官品质和风味好。 

Experimental study on technology of vacuum freeze-drying of concentrated soup of yak bone

The concentrated soup of yak bone was firstly prepared by high pressure cooking ways combined with Chinese traditional ways, and then made into instant compound product by vacuum freeze- drying technologies. The technologies were optimized with both the single-factor and the orthogonal experiments, based on the rate of dried products and according to evaluating the effects of the comprehensive indexes, including shape-keep rate, products performance, sensory evaluation and flavor in the process.The results showed that the material thickness was 3mm, the vacuum value of drying chamber was 20Pa, the drying time was 6h, and the pre- freezing temperature was- 40℃. The analysis of the recovery properties of water, the surface morphology and the flavor components indicates that the vacuum freeze- dried concentrated soup of yak bone product has stable performance, high organoleptic quality and good taste.