After filtering, only the oils neutralized that resulted in high yields (T1, T3 and T4) were washed, as the other quantities were insignificant for posterior analysis. Fig. 2shows the acidity measured and calculated after the washing of treatments with higher amounts of samples. The neutralization process has proven to be efficient in acidity reduction, lowering all numbers. The highest number decreased from 40.42 mg to 1.93 mg of KOH g−1 of oil. It also reduced acidity in treatment 4–0.47 mg of KOH g−1 of oil. This result was similar to that of soy oil acidity, which averages 0.48 mg of KOH g−1of oil. The Brazillian Health Surveillance Agency (ANVISA, 1999) does not present a specification of acidity to jatropha, however, all the results of acidity posterior to neutralization are within the limit of 2 mg of KOH g−1 of oil determined by this legislation to other oilseeds.Tapanes (2008)states that for the acidity of jatropha to