The science of dog food gets an in-depth look by Mary Roach in “The Chemistry of Kibble,” as the acclaimed author goes behind the scenes at AFB International, a company that makes flavor coatings for dry pet foods. The whole article is worth a read, but here are our favorite quotes to whet your, um, appetite:

1. “Pet foods come in a variety of flavors because that’s what humans like, and we assume our pets like what we like. We’re wrong.”

2. “Pyrophosphates have been described to me as ‘cat crack.’ Coat some kibble with it, and the pet food manufacturer can make up for a whole host of gustatory shortcomings.”

3. “There is no way to know or imagine what the taste of pyrophosphate is like for cats. It’s like a cat trying to imagine the taste of sugar. Cats, unlike dogs and other omnivores, can’t taste sweet.”

4. “People blanch to see ‘fish meal’ or ‘meat meal’ on a pet food ingredient panel, but meal — which variously includes flesh, organs, skin, and bones — most closely resembles the diet of dogs and cats in the wild.”

5. “Everyone wants to be Meow Mix.”

6. “Two animal techs dressed in surgical scrubs stand facing each other. They hold shallow metal pans of kibble in various shades of brown, one in each hand. Around their ankles, 20 cats mince and turn. The techs sink in tandem to one knee, lowering the pans.”

7. “Kleinsorge mentions that a dog named Mohammid has lately had an upset stomach, and Porkchop likes to eat the vomit. ‘So that’s cutting into Porkchop’s appetite.'”

8. “The challenge is to find an aroma that drives dogs wild without making their owners, to use an Amy McCarthy verb, yak.”

9. “‘Cadaverine is a really exciting thing for dogs,’ says Rawson. ‘Or putrescine.’”

10. “The average dog’s nose can be up to 10,000 times more sensitive than the average human’s. A flavor that to you or me is reminiscent of grilled steak may be overpowering and unappealing to a dog.”

11. “[On the 1973 Food Scorecard nutritional test] Alpo scored 30 points, besting salami and pork sausage, fried chicken, shrimp, ham, sirloin steak, McDonald’s hamburgers, peanut butter, pure beef hotdogs, Spam, bacon, and bologna.”

12. “Organs in general are among the most nutritionally rich foods on earth. Lamb spleen has almost as much vitamin C as a tangerine. Beef lung has 50 percent more. Stomachs are especially valuable because of what’s inside them.”

13. “Interpreting animals’ eating behaviors is tricky. By way of example, one of the highest compliments a dog can pay its food is to vomit.”

Read the whole fascinating article at PopSci.