低温发酵乳品质特性研究

Study on the Quality of Yoghurt Fermented at Low Temperature

以青藏高原传统发酵牦牛乳中分离的保加利亚乳杆菌(编号为CGMCC2603)和酸乳球菌(编号为CGMCC1.3920)为研究对象,研究菌株低温发酵酸乳的感官特性、后酸化能力、粘度及双乙酰含量变化。结果表明试验菌株在25°C发酵的酸乳凝乳状态较好,冷藏14d后酸度分别提高29.2°T和8.5°T,后酸化较弱。冷藏期间粘度变化与发酵温度没有直接关系。低温有利于双乙酰的积累,双乙酰含量最高分别为12.04μg/mL和9.78μg/mL。本研究对开发低温发酵剂具有重要意义。

Take Lactobacillus delbrueckii ssp.bulgaricus （accession number is CGMCC2603） and Lactococcus lactis （accession number is CGMCC1.3920） that isolated from Tibetan fermented yak milk at low temperature as starter. Sensory analysis, post acidification, viscosity and diacetyl were measured for all the yoghurt fermented at different temperature. Results indicated that yoghurt fermented at 25℃ with experimental strains had good texture; the titrable acidity increased 29.2°T and 8.5°T respectively during storage and had weak post acidification. Viscosity was not increased with the decreasing of the fermented temperature. Decreases in temperature might contribute to the accumulation of diacetyl, the maximum value of diacetyl were 12.04ug/mL and 9.78ug/mL, respectively. This study had important significance for the development of the starter culture fermented at low temperature.