摘要
以分离自西藏灵菇发酵液的3株产胞外多糖的假肠膜明串珠菌为研究对象,对其产胞外多糖能力、发酵性能及流变学特性进行了研究。结果表明:本研究分离得到的3株假肠膜明串珠菌均具有较高的产孢外多糖的能力,菌株R5的胞外多糖产量最高,达到454.67 mg/L;三株菌生长过程符合细菌生长典型规律,产酸时期主要在菌株的对数生长期,适于发酵乳制品生产,其中菌株R5发酵酸乳的组织状态、风味的感官评分为86分,明显优于其他两株菌。流变学特性表明,三株菌制备的发酵乳的表观黏度都随剪切时间的延长而降低,呈现剪切稀释的流动特征,黏度大小依次为R5>R2>R1;均能够形成触变环,为正触变性流体,R1发酵乳与R5发酵乳触变环面积相近,分别为2301.72、2924.09 1/s Pa,较R2发酵乳(4697.82 1/s Pa)小;三株菌制备的发酵乳的G'值(弹性模量)都高于G″值(粘性模量),均是弹性模量占优势,表现出类固体特性,菌株R5发酵出的酸乳具有较高的弹性和黏性。通过比较三株菌的发酵性能与流变学特性,表明菌株R5相较于其他两株菌具有较强的产胞外多糖的能力,较高的表观黏度,较好的粘弹性,结构恢复能力较强,发酵的酸乳具有更好的组织结构,具有一定的应用潜力。
In this study,the exopolysaccharide content,fermentability and rheological properties of three srains with exopolysaccharide produced were evaluated. The results showed that Leuconostoc peudomesenteroides of three srains produce exopolysaccharide,exopolysaccharide content of R5 was 454.67 mg / L.The growth process three srains was typical bacterial growth,acid production period mainly was logarithmic phase of strain,they were suitable for fermented dairy production,R5 of them had better organization status and flavor and sensory score was 86. The result of rheological properties showed that apparent viscosity was reduced with the shearing time of fermented dairy products from three strains,they presented flow characteristics of the shear thinning,viscosity size was R5 R2 R1.Fermented milk of three strains could form the thixotropic loop,they were the thixotropic fluid,hixotropic loop area of fermented milk of R1 and R5 was 2301.72（ 1 / s Pa） and 2924.09（ 1 /s Pa）.R2 was 4697.82（ 1 /s Pa）.G＇ values were higher than G＂ of fermented milk from three strains and elastic modulus was preferred,fermented milk of R5 has higher elastic and viscous.By comparing their fermentability and rheological properties,strain of R5 had higher exopolysaccharide content,its fermented milk revealed the highest apparent viscosity,viscoelasticity and strongest stability,strain of R5 had potential applications.The result illustrated that exopolysaccharide producing strains could give good texture for fermented milk.
出处
《食品工业科技》
CAS
CSCD
北大核心
2017年第4期106-110,115,共6页
Science and Technology of Food Industry
基金
国家自然科学基金项目(31260395)
关键词
西藏灵菇
胞外多糖
假肠膜明串珠菌
发酵性能
流变学特性
Tibetan kefir
exopolysaccharide
Leuconostoc pseudomesenteroides
fermentability
rheological properties
