Moringa oleifera Lam. has been reported as a natural coagulant in the treatment of surface waters; however its use presents some disadvantages such as low performance in the coagulation/flocculation of low turbidity waters and organic matter increase in the treated water. In addition, there is little specialized literature about coagulation proteins present in Moringa seeds and their characterization. Thus, this work had as objective the fractionation of Moringa oleifera seeds protein, characterization of the fractions obtained and evaluation of potential coagulant activity in different water turbidity. Based on the results obtained it was found that the globulin and albumin presented the highest values for protein fraction in Moringa seeds with 53% and 44% respectively. Percentage removals of 87.40% of color, 89.71% of turbidity and 79.46% of UV254nm, were reached using 13 mg/L of the globulin coagulant for treatment of low turbidity water (50 NTU) without entailing excessive increase of the dissolved organic carbon in the treated water, even being considered a natural coagulant. Therefore, the use of fractionation as initial purification technique proved to be beneficial by producing a coagulant with high efficiency in the treatment of the low turbidity water. (C) 2017 Elsevier B.V. All rights reserved.