Answer: At this point, your researchers can say with certainty that the food INCLUDES PROTEIN.
Protein is One of three major classes of food or source of food energy abundant in animal-derived foods (i.e. meat) and some vegetables, such as legumes. It is a large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are held together by peptide bonds.
Protein is composed of smaller chemical units called amino acids. Amino acids are made of the elements CARBON, HYDROGEN, OXYGEN, NITROGEN.