采用真空浓缩方法，获得固形物含量为12%，14%，16%，18%的羊乳，用其生产酸羊奶，探索不同乳固形物浓度对酸羊奶品质的影响。从凝乳特性，质构特性，风味物质，乳酸菌数等方面对不同固形物浓度的酸羊奶进行分析，并且采用扫描电镜对其微观结构进行比较。结果显示，随着羊乳固形物浓度的提高，酸羊奶的凝乳时间显著降低，酸度逐渐增大，持水性显著增高；酸羊奶的双乙酰浓度和乙醛浓度在乳固形物含量为16%时达到最高；随着羊乳固形物浓度的提高，酸羊奶的黏度增加了149.07%，酸羊奶的硬度，粘性，胶黏度显著增加，凝聚力显著降低；乳酸菌总数在羊乳固形物浓度为16%时达到最大值6.35×10⁹?cfu/mL；羊乳固形物浓度为16%时，酸羊奶的微观结构非常致密，空隙直径最小为2.85?μm；综上，羊乳固形物浓度为16%时，酸羊奶风味最佳，凝乳质地较硬，黏度较高，乳酸菌总数最高，其品质最好。

In this study, goat milk was concentrated by vacuum concentration to study the effect of different concentration of goat milk (12%, 14%, 16% and 18%) on the quality of yogurt.The quality of goat milk yogurt was analyzed by determination of the coagulation characteristics, texture, flavor substances, and viable counts of lactic acid bacteria. Meanwhile, the microstructure of yogurt fermented with different concentration goat milk was observed by scanning electron microscope. The results showed that the fermentation time decreased with the increase of goat milk concentration, accompanied by the increment in acidity and water holding capacity; High concentrations of 2,3-butanedione and acetaldehyde were recorded in yogurt fermented with goat milk with solids of 16%. The viscosity of goat milk yogurt increased by 149.07% with the total solids of goat milk increased.Yogurt fermented with goat milk with solids of 16% displayed with goodtexture characteristics evaluated by the hardness, adhesiveness and gumminess and cohesiveness; The viable counts of lactic acid bacteria in the yogurt was 6.35×10⁹?cfu/mL which is the highest among different milk concentration.The most compact microstructure was measured in yogurt fermented with 16% goat milk with pore diameter of 2.85?μm. In conclusion, when the concentration of goat milk is 16%, goat milk yogurt showed the best quality measured by the flavor and texture characteristics, and viable counts of lactic acid bacteria.