식품첨가물로 허용되어 있는 알긴산나트륨, 알긴산프로필렌글리콜(PGA), 카르복시메틸셀룰로오스나트륨(CMC), 펙틴 등 4종의 다당류를 이용하여 달걀 노른자의 수용성 단백질을 분리하기 위한 조건을 반응표면 분석법으로 조사하였다. Rotatable hexagon design으로 실험을 계획하여 다당류의 사용농도 5개 수준, 반응 pH 3개 수준에서 상층액 중의 단백질과 지방질 함량을 각각 측정하여 2차 회귀모형을 구하였다. 통계분석 결과 반응 pH가 다당류의 농도보다 난황 단백질-다당류 상호작용에 더 영향을 미치는 요인으로 밝혀졌다. 각 반응도의 contour plot을 작성, 분석하여 수용성 난황 단백질 분리의 조건으로 알긴산나트륨; 농도 $0.23{sim}0.25%$, $pH;5.9{sim}6.0$, PGA; 농도 $0.15{sim}0.17%$, $pH;4.3{sim}4.5$, CMC; 농도$0.30{sim}0.31%$, pH 3.0 펙틴; 농도 $0.09{sim}0.10%$, $pH;5.6{sim}5.8$을 설정하였다.
Response surface methodology was employed to investigate the conditions for separating water-soluble proteins from egg yolk using sodium alginate, propylene glycol alginate (PGA), sodium carboxymethylcellulose (CMC) and pectin which are approved as food additives. Effects of plysaccharide concentration and pH of the reaction system on protein and lipid contents in the supernatant were evaluated at respectively five and three levels of concentration and pH using rotatable hexagon design. Statistical analysis showed that pH of the system was a more important factor than polysaccharide concentration as it significantly affected all two responses. Separating conditions established by a graphical optimization technique were $0.23{sim}0.25%$ of sodium alginate at $pH;5.9{sim}6.0$, $0.15{sim}0.17%$ of PGA at $pH;4.3{sim}4.5$, $0.30{sim}0.25%$ of CMC at pH 3.0, and $0.09{sim}0.10%$ of pectin at $pH;5.6{sim}5.8%$.
