Saren raised his eyebrows (or rather, the part of his head where a human has eyebrows) at several of remarks of Frieza's speech. Clearly this creature held belief in its own abilities - whether it had good reason to where yet beyond Saren's ability to judge.  Its choice of clothing was certainly atypical, as was its general biology and physical appearence. He was anxious to meet his squad's leader - whoever it once had been called a fool, but Saren himself had been called a fool when he had been allied with Soveriegn, and that had certainly been the logical answer, even if it suited Soveriegn more than it did galactic civilisation. His squadmate, Charlotte, made a surprising (though not completely illogical) remark about Frieza's clothing, before eating a brightly coloured form of human food... candy, possibly? Saren had not studied foreign diets extensively, but he thought this was apparently something of a delicacy among the Humans. It would be poisonous to him anyway, being made for beings with levo-amino acids rather than his own dextro-amino acids.

Saren was particularly unsure about having to work with humans. After the Relay 314 Incident, and Anderson's failed Spectre trial, he had developed a prejudice towards them. Fighting alongside them would not be something he was used to. Still, after the events that allowed the various universes to become linked, it became clear that humans were some of the most commonly existing sentient races throughout the multiverse. This might not be a coincidence, and with trillions upon trillions of them now in existence, how bad could their best be? He found out exactly how bad when John Freeman demonstrated his extradordinary capabilities. 

[colour=MediumBlue][b][i]"Saren Arterius, Citadel Spectre."[/i][/b][/colour] Saren says, before realising know one knows what that means. [i][b][colour=MediumBlue]"That is, I'm a government soldier charged with the defence of the galaxy answerable only to the highest levels of authority, with top-of-the-line gear and funding, and the authority to do as I choose in order to get my job done. Does that answer all of your questions?"[/colour][/b][/i]