초록
$\beta$-cyclodextrin adsorption and saponification methods were applied to isolate and purify cholesterol from the by-product of the low-cholesterol egg yolk product. They by-product was prepared from processing low-cholesterol egg yolk followed by extracting with chloroform to remove $\beta$-cyclodextrin and concentrated to 3,069 mg% cholesterol. When $\beta$-cyclodextrin method between two purification methods was applied, 50% ethanol as a solvent showed higher cholesterol concentration of 5.82% rather than the other solvents. Repeated purification of 3 times could not improve the cholesterol concentration significantly(p<0.05). In case of purification using saponification method, hexane as a solvent for extraction of unsaponificated materials was more efficient to increase cholesterol concentration than chloroform and ether. 60 times(v/w) saponification solution (95% ethanol:33% KOH = 94:6) of sample weight was most effective to increase the cholesterol concentration of 35.7%. Repeated purification process by saponification method could increase cholesterol concentration to 95.7% by 4 times repetition.