icularly 10 to 50 mass % of at least one compound of formula (i): r???o-(g)x-h, wherein r is a linear saturated aliphatic radical including 12 to 22 carbon atoms, g is the remainder of a reducing sugar selected from the group including glucose, xylose and arabinose, and x is a decimal number greater than or equal to 1 and lower than or equal to 10; 95 to 30 mass % and more particularly 90 to 50 ma