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Chen H.,Shaanxi University of Science and Technology | Zhang Q.,Shaanxi University of Science and Technology | Wan H.,Shaanxi Yatai Dairy Co. | Shu G.,Shaanxi University of Science and Technology | Li H.,Shaanxi Yatai Dairy Co.
Advance Journal of Food Science and Technology | Year: 2015

In order to obtain the optimum inoculum size of goat milk fermented by probiotics, the total inoculum size containing L. acidophilus or L. casei on pH, acidity and viable counts and sensory during fermentation were studied on the basis of S. thermophilus and L. bulgaricus as starter cultures. The results showed as follows: the optimum inoculum size of L. acidophilus and L. casei were all 7% and goat milk was fermented at 39°C for 4.5h. The pH, acidity, the viable counts of L. acidophilus and the total viable counts were respectively 4.48, 91°T, 1.60×107cfu/mL and 1.69×109cfu/mL. The pH, acidity, the viable counts of L. casei and the total viable counts were respectively 4.38, 96°T, 2.80×108cfu/mL and 2.20×109cfu/mL. © Maxwell Scientific Organization, 2015. Source


Shu G.,Shaanxi University of Science and Technology | Lei N.,Shaanxi University of Science and Technology | Wan H.,Shaanxi Yatai Dairy Co. | Chen H.,Shaanxi University of Science and Technology | Li H.,Shaanxi Yatai Dairy Co.
Carpathian Journal of Food Science and Technology | Year: 2015

In order to obtain the optimum parameters of goat milk fermented by starter cultures containing B. bifidum and L. casei, the effect of incubation temperature and inoculum size on the fermentation were studied by single factor test. Incubation temperature was 35°C, 37°C, 39°C, 41°Cand 43°C, the inoculum size was 1%, 3%, 5%, 7% and 9%, respectively. The results showed that the optimum incubation temperature was 39°C, the viable counts of B. bifidum, L. casei, the total viable counts, pH, acidity and sensory evaluation in BC-goat yogurt were 1.40×107cfu/ml, 1.30×107cfu/ml, 1.98×109cfu/ml, 4.58, 80.0°T and 7.36, respectively. The optimum inoculum size was 7%, the viable counts of B. bifidum, L. casei, the total viable counts, pH, acidity and sensory evaluation in BC-goat yogurt were 8.40×107cfu/ml, 8.50×107cfu/ml, 2.30×109cfu/ml, 4.17, 102.2°T and 7.13, respectively. Source


Chen H.,Shaanxi University of Science and Technology | Zhang J.,Shaanxi University of Science and Technology | Wan H.,Shaanxi Yatai Dairy Co. | Dang Y.,Shaanxi University of Science and Technology | Shu G.,Shaanxi University of Science and Technology
Advance Journal of Food Science and Technology | Year: 2014

Response Surface Methodology (RSM) was advantageously used to optimize production conditions of immobilization of β-galactosidase onto chitosan beads. The influence of immobilization conditions on the immobilized enzyme activity was studied by using Box-Behnken experimental design, resulting in the appropriate average values of OD420 and the maximum value of immobilized enzyme activity. This illustrated that the experimental model was reliable and the experimental results were of good stability. Analysis of variance was performed to determine the adequacy and significance of the quadratic model. Various model parameters also could be seen from F value that the interaction between three factors was not particularly obvious, but effects of X1, X1 2, X2 2 and X3 2 on the activity of immobilized enzyme were very obvious. The optimisation parameters studied in accordance with the results were: the appropriate average values of OD420 loaded in the range from 0.713 to 0.721. Furthermore the immobilized enzyme activity reached about 162U/g when the adsorption time, adsorption pH and cross-linking pH were 4h, 7 and 7, respectively. Thus, the relative activity of β-galactosidase immobilized increased more than 37% compared with the previous single factor research. © Maxwell Scientific Organization, 2014. Source


Chen H.,Shaanxi University of Science and Technology | Song Y.,Shaanxi University of Science and Technology | Wan H.,Shaanxi Yatai Dairy Co. | Wang Y.,Shaanxi University of Science and Technology | Shu G.,Shaanxi University of Science and Technology
Advance Journal of Food Science and Technology | Year: 2014

This present study is based on the single factor test and the significant factors of emulsification conditions, which influence the process of microencapsulation of B. bifidum BB28 and BB01, will be screen out by Plackett-Burman experimental. Bifidobacterium BB0I and BB28 were encapsulated by using emulsion method respectively. Several factors, such as alginate concentration, cell suspension-alginate ratios, CaCl2 concentration, Tween 80 concentration, emulsification time, encapsulating time and oil-water ratios have been investigated, the results showed that sodium alginate concentration, cell suspension-alginate ratios, encapsulating time and emulsification time have a significant effect for Bifidobacterium BB01 microcapsules; CaCl2 concentration, cell suspension-alginate ratios, sodium alginate concentration and emulsification time have a significant effect for Bifidobacterium BB28 microcapsules. © Maxwell Scientific Organization, 2014. Source


Chen H.,Shaanxi University of Science and Technology | Song Y.,Shaanxi University of Science and Technology | Liu N.,Shaanxi University of Science and Technology | Wan H.,Shaanxi Yatai Dairy Co. | And 2 more authors.
Acta Scientiarum Polonorum, Technologia Alimentaria | Year: 2015

Background. Lactobacillus acidophilus has become increasingly popular because of their beneficial effects on health of their host, and are called proboscis. In order to exert beneficial effects for probiotics, they must be able to tolerate the acidic conditions of the stomach environment and the bile in the small intestine. Microencapsulated form has received reasonable attention, since it can protect probiotic organisms against an unfavourable environment, and to allow their release in a viable and metabolically active state in the intestine. The aim of this study was to investigate some factores, such as chitosan solution pH and concentration, xanthan concentration, cell suspension-xanthan ratio, mixed bacteria glue liquid-chitosan ratio, which impacted the process of microencapsulation of L. acidophilus. Material and methods. In this study, L. acidophilus was immobilized with xanthan/chitosan gel using extrusion method. The viable counts and encapsulation yield of L. acidophilus encapsulated in different chitosan solution pH (4.5, 5, 5.5 and 6), in different chitosan concentration (0.5%, 0.7%, 0.9% and 1.1%), in different xanthan concentration (0.5%, 0.7%, 0.9% and 1.1%), in different cell suspension-xanthan ratios (1:5, 1:10, 1:15 and 1:20), in different mixed bacteria glue liquid-chitosan ratios (1:3, 1:4, 1:5 and 1:6), have been investigated by single factor experiment method. Results. The optimum conditions of microencapsulated L. acidophilus have been observed. The optimum chitosan solution pH for L. acidophilus was 5.5; the optimum chitosan concentration was 0.9%; the optimum xanthan concentration was 0.7%; the optimum cell suspension-xanthan ratio was 1:10; the optimum mixed bacteria glue liquid-chitosan ratio was 1:3. Conclusions. These results will be helpful to further optimize the process of L. acidophilus microencapsulation, and provide reference for obtaining higher viable counts and entrapped yield of L. acidophilus microcapsules. © by Wydawnictwo Uniwersytetu Przyrodniczego w Poznaniu. Source

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