Abstract:
To explore the feasibility of microcapsule technology in ice cream production,
Lactobacillus acidophilus CICC 6075 microcapsules were prepared by emulsification with lactoprotein as the wall material. In this experiment,the effects of microcapsules(group C)and naked probiotics(group B)on the physical and chemical properties and sensory properties of ice cream were investigated by using ice cream without probiotics(group A)as blank control. As the results showed,neither the addition of naked
Lactobacillus acidophilus CICC 6075 nor microcapsule had significant effect on the properties of ice cream. However,during the processing and storage of ice cream,microcapsules provided good protection for CICC 6075 due to their dense structure,which significantly increased the number of viable bacteria of CICC 6075.The number of viable CICC 6075 in group B decreased(1.20±0.08)lg CFU/g during stirring and freezing,while the number of viable CICC 6075 only reduced(0.09±0.07)lg CFU/g in group C. After storage at-18 ℃ for 150 d,the number of viable CICC 6075 decreased to(5.54±0.03)lg CFU/g in group B,lower than the minimum threshold for probiotics to play their health benefits. While group C only decreased(0.60±0.08)lg CFU/g,and the final viable count was as high as(8.09±0.03)lg CFU/g. In addition,it was also found in digestive characteristics test that the gastric acid tolerance and adhesion of CICC 6075 to epithelial cells of small intestinal significantly decreased in group B(6.16%±0.04%,16.76%±0.05%)during the low temperature storage of 150 d,and were significantly higher than those of group C(1.92%±0.07%,4.47%±0.09%). In conclusion,microcapsule technology could significantly improve the resistance of probiotics to adverse environments(such as low temperature and gastric juice)during the processing and storage of ice cream,so it could not only guarantee the good quality and characteristics of ice cream,but also improve its functional activity,which had a certain application prospect.