PROBLEM TO BE SOLVED: To provide a method for producing a highly purified acid type sophorolipid-containing material substantially not containing acetic acid.SOLUTION: The method comprises the steps of (i) and (ii-b): (i) adjusting pH of crude acid type sophorolipid (SL)-containing material to an acidic region lower than 7 and (ii-b) leaving standing still the acidified crude acid type SL-containing material obtained in the step (i) under a low temperature condition determined as in the following conditions (a) - (d) according to its pH, and then washing the generated gelled material with a cold, water-containing solvent of 15°C or lower to obtain gelatinous acid type SL-containing material. The conditions are:(a) pH4 or lower: -25°C-15°C (b) higher than pH4 and not higher than pH5: -25°C-10°C (c) higher than pH5 and not higher than pH6: -25°C--10°C and (d) higher than pH6 and lower than pH7: -25°C--20°C.COPYRIGHT: (C)2014,JPO&INPIT【課題】酢酸を実質的に含まないことを特徴とする高純度な酸型ソホロリピッド(SL)含有物を製造する方法を提供する。【解決手段】下記工程(i)及び(i-b)を実施する:(i)粗精製酸型SL含有物のpHを7未満の酸性領域に調整する工程、及び(ii-b)前記工程(i)で得られた酸性化粗精製酸型SL含有物を、そのpHに応じて下記の低温条件下に静置し、生じたゲル化物を15℃以下の水を含む冷溶媒で洗浄し、ゲル状の酸型ソホロリピッド含有物を取得する工程:(a)pH4以下の場合、-25℃~15℃、(b)pH4より高くpH5以下の場合、-25℃~10℃、(c)pH5より高くpH6以下の場合、-25℃~-10℃、(d)pH6より高くpH7未満の場合、-25℃~-20℃。【選択図】なし
