Perfume: The Story Of A Murderer help with homework: Grenouille becomes, toward the end of the novel

Grenouille becomes, toward the end of the novel, a kind of olfactory vampire, killing young women to rob them of their scents. “What he coveted was the odor of certain human beings: that is, those rare humans who inspire love. These were his victims” [p. 188]. Why does he need the scents of these people?