Abstract
Hurdle technique was used to remove cholesterol efficiently from liquid egg yolk. The quality of the low cholesterol egg products from the process were evaluated. From the 75 % cholesterol reduced egg yolk through $\beta$-cyclodextrin treatment. 2 times weight of soy bean oil was added to the egg yolk and homogenized followed by centrifuged to be maximized to remove cholesterol. When the pH of the yolk was adjusted to 9, 92 % of cholesterol was removed while 95.4 % of cholesterol was removed when 3 times weight of soy bean oil was added to the egg yolk. As the results of application of supercritical carbon dioxide extraction to the 75 % cholesterol reduced egg yolk through ${\beta}$-cyclodextrin treatment, 92.5 % of the cholesterol was removed from the egg yolk at $35^{\circ}C$, 4,500 psi, for 4 hours under co-solvent. The quality characteristics of the produced low cholesterol egg products were analysed. The cholesterol reduced egg yolk produced from ${\beta}$-cyclodextrin and soy bean oil treatment showed the lower emulsion capacity compared with control. The fatty acid composition of the cholesterol reduced egg yolk produced from ${\bet}a$-cyclodextrin and soy bean oil treatment showed increased C18:2 and C18:3 compared with control while decreased C16:1 and C18: 1 compared with control. The saponification method with extracting solvent of hexane showed that cholesterol concentration was 28.1 %. The quantity of hydrolysis solution(95 % ethanol : 33 % KOH = 94 : 6) was varied from 40 to 80 times of sample weights and the cholesterol concentration of 35.7 % was the highest result in the 60 times(v/w) hydrolysis solution. Cholesterol concentration of 35.7 % was recovered at the first trial with saponification method. but it could be improved up to 95.7 % after 4 times repetitive purification.