To find proof as to whether he is "in love" or not, Yukimura pats Himuro on the head from point-blank range. Seeing this, Ibarada, an upperclassman in the Ikeda Lab, talks about the need for a control experiment. In other words, in order to prove that the racing of his heart is because of Himuro specifically and not just because he's facing a woman, Yukimura has to pat Kanade and Ibarada on the head too. Himuro, on the other hand, sets out to prove that food made with love tastes better and cooks, but...
one with love and one without, and set them 
out so that you can't tell which is which,
واحد صنع بحبّ وواحد من دونه ووضعهما
 .بطريقة لا يمكن فيها التفريق بينهما
und einmal ohne und gibst sie so aus,
dass man sie nicht unterscheiden kann.
uno con l'amore e uno senza,
disponeteli di modo da non poterli distinguere,
em ordem aleatória,
pra não poder diferenciá-los,
с любовью и без, 
и использовать слепой метод,