The present article reports new data on the Ti48(O18,O17)Ti49 reaction at 275 MeV incident energy as part of the systematic research pursued within the NUMEN (NUclear Matrix Elements for Neutrinoless double β decay) project. Supplementary measurements of the same reaction on O16 and Al27 targets were also performed in order to estimate the background arising from the use of a composite target (TiO2+Al27). These data were analyzed under the same theoretical framework as those obtained with the titanium target in order to reinforce the conclusions of our analysis. Differential cross-section angular distribution measurements for the O8+17 ejectiles were performed in a wide angular range by using the MAGNEX large acceptance magnetic spectrometer. The experimental results were analyzed within the distorted-wave and coupled-channels Born approximation frameworks. The optical potentials at the entrance and exit channels were calculated in a double folding approach adopting the São Paulo potential, and the spectroscopic amplitudes for the projectile and target overlaps were obtained from large-scale shell model calculations. The differential cross sections are well described by the theoretical calculations, where a weak coupling to collective excitations of projectile and target is inferred. The sensitivity of transfer cross sections on different model spaces adopted in nuclear structure calculations is also discussed.