Place it right before the first bite in a food review edit, then follow it with a cartoon munch for the eating itself and let the reaction carry the verdict before you cut back to talking.
このサウンドについて
A single human voice holds a long, drawn-out 'mmmmmmmmmmmm' hum for just over two seconds, with no words or music behind it. The effect is openly satisfied and a little theatrical, like approval that is too pleased to bother forming a sentence, which makes the moment feel warm and amused rather than serious.