基于特征风味定向筛选酸奶用乳酸菌

Selection of Lactic Acid Bacteria for Yoghurt Based on Characteristic Flavor Orientation

针对国内酸奶发酵剂成本高,菌剂被国外垄断的问题。本实验基于特征风味物质乙醛和双乙酰,从市售酸奶产品和菌剂中定向筛选出高风味物质含量菌株,经复配和感官评定,得到适合生产菌株。实验共分离鉴定出58株乳酸菌,包括嗜酸乳杆菌(9株)、鼠李糖乳杆菌(2株)、德氏乳杆菌(4株)、嗜热链球菌(39株)、乳酸乳球菌乳酸亚种/乳酸乳球菌(4株)。产乙醛能力呈现出德氏乳杆菌>嗜热链球菌>乳酸乳球菌>嗜酸乳杆菌>鼠李糖乳杆菌,最高达到25.57μg/g。产双乙酰能力呈现出鼠李糖乳杆菌>嗜酸乳杆菌>嗜热链球菌>乳酸乳球菌>德氏乳杆菌,最高达到3.57μg/g。德氏乳杆菌和鼠李糖乳杆菌产酸能力较强。菌株复配后大多风味物质含量提高,在一定条件下,呈现出乙醛/双乙酰比例越高,乙醛含量越高,感官风味越好。

For the domestic yogurt culture starter cost is high, the culture starter was monopolized by foreign coun- tries. In this study, the high flavor content strains were screened from the commercially available yoghurt products and culture starter based on the characteristic flavored acetaldehyde and diacetyl, and the strain was prepared by complex and sensory evaluation. A total of 58 lactic acid bacteria were identified, including Lactobacillus aci- dophilus （9 strains）, Lactobacillus rhamnosus （ 2 strains）, Lactobacillus delbrueckii （ 4 strains）, Streptococcus ther- mophilus （39 strains）, Lactocaccuslactis subsp. Lactis/Lactococcuslactis （4 Strain）. The ability to produce acetalde- hyde showed Lactobacillus delbrueckii〉Streptococcus thermophilus 〉Lactococcuslactis 〉LactobaciUus acidophilus 〉Lacto- bacillus rhamnosus, up to 25.57μg/g. The ability to produce diacetyl is Lactobacillus rhamnosus 〉Lactobacillus acidophilus 〉Streptococcus thermophilus〉Lactacoccuslactis 〉Lactobacillus delbrueckii, up to 3.57μg/g. Lactobacillus delbrueckii and Lactobacillus rhamnosus have strong ability to produce acid. After the strain was mixed, the flavor content increased, under certain conditions, showing the higher proportion of acetaldehyde/diacetyl, the higher the content of acetaldehyde, the better the sensory flavor.