Research On The Key Technologies Of Active Probiotic Fermented Beverage With Goat Milk

Nowadays,active probiotic milk drink is widely favored by consumers because of its unique flavor,color and multiple nutritional features.At present,the mainstream of probiotic drink in the market is using cow's milk as basic material,and the probiotic drink based on goat's milk has not yet developed.At present,consumer's demand for goat milk is continuously increasing.In this study,the development of active probiotic average contributes to the diversity of goat milk products,the demand of consumers and the promotion of industrial development.There are many problems in active probiotic milk drink during its shelf life.In order to improve the quality of active probiotic fermented beverage with goat milk,this research studies the fermented culture,prebiotic enrichment capability,fermentation condition,formulation process and quality change of its shelf life,the main conclusions are as followed:?1?Screening of fermentation strains: this article screens among three commercial starter cultures which have good effects in application?A₁?A₂?A₃?and three performanceoptimized cultures owned by laboratory?B₁?B₂?B₃?.Then this article draws growth curves through the measure of active bacteria number,acidity,PH and etc.The result shows that A₁ in goat's milk is better than other five starter cultures in active bacteria number?10⁹ CFU/mL?,acidity?>140°T?and other aspects.Thus,A₁ is a good starter culture for active probiotic fermented beverage with goat milk.?2?Screening and optimizing of prebiotics: this article studies the prebiotic enrichment capability of FOS,GOS,inulin and IMO by using viable count as a index and then finishes the compounding test.The result shows that when the ratio of FOS and inulin is 9:1,the promotional effect for A₁ is the most significant,which is better than using them alone.At this time,the viable count of active probiotic fermented beverage with goat milk is 2.86 ×10⁹CFU/mL.Study on fermentation technology: the acidity of titration and the viable count are evaluated.single factor and orthogonal experiments are used to test the dosage,inoculum size,and fermentation time.The result shows that the optimal fermentation condition for active probiotic goat's milk drink is: the prebiotic dosage is 1.50%,the inoculum size of prebiotic is 4% and the fermentation time is 40 h.?3?Product stability research: this article uses single factor and orthogonal experiments to define the optimal parameter by using centrifugal sedimentation rate,particle size distribution and sensory evaluation as indexes.Heat treatment,sucrose,pH,stabilizer and homogeneous pressure were studied as single factors.The result shows the best fermentation processing is 20 MPa of the homogeneous pressure,the browning time is 120 min,8% of the sucrose dosage and 0.55% of the stabilizer dosage.?4?Evaluation of product storage period: quality changes are compared under the temperature of 4?,25? and 37? by using the active bacteria number,titratable acidity,pH,centrifugal sedimentation rate,particle size distribution and sensory evaluation as indexes.The result shows that the optimal storage temperature is 4?.No significantly change is found in the quality of active probiotics beverage which fermented in goat milk during 28 days.