Investigation of Milk Cholesterol Reduction Using both Free and Immobilized Lactobacillus Acidophilus ATCC1643 in Sodium-Alginate

Lactobacillus acidophilus is one of the major microorganisms which are famous for their effects on cholesterol. In this study we have investigated the effect of lactobacillus acidophilus ATCC1643 on removing the milk cholesterol and additionally we have immobilized lactobacillus acidophilus ATCC1643 cells in sodium-alginate and observed its effect on milk cholesterol removing. Also, we have researched about the effect of some factors including: bacteria cells number (both free and immobilized cells) and immobilized cells bead size on cholesterol removing rate and ultimately the extracted results were compared together. The results presented that free cells could reduce cholesterol to lower than 0.5mg/100ml milk. Also, smaller bead size resulted higher cholesterol reduction. Increasing the number of immobilized cells showed significant effect on cholesterol removal to about 96%. Also reusability of the beads showed that immobilized cells are active in cholesterol processing for three times.