The Maillard reaction is a chemical reaction that occurs between proteins and sugars when food is impacted by heat. It's also known as non-enzymatic browning. This process gives browned food its distinctive flavor.
The Maillard reaction occurs in all of the listed examples. Coffee, bread, and meat all contain sugars and proteins. Roasting, toasting, and searing are all forms of thermal processing, which means that heat is involved. This heat impacts the sugars and proteins, which leads to the Maillard reaction.
The literary device used in these lines is Personification.
The personification is a figure of speech in which a thing is given human attributes. The non-human objects are portrayed in such a way that we feel they have the capacity to act like human beings. This device makes the piece more interesting to read and makes it more sensitive to the reader.