Specific heat capacity is a fundamental physical property of all matter, including food items like pizza, making this claim a matter of basic scientific observation that requires no formal citation.
The claim asserts that pizza has a specific heat capacity that can be measured experimentally. Specific heat capacity is an intrinsic physical property of any substance with mass and temperature. Stating that a physical object has measurable thermal properties is trivially true by definition and everyday thermodynamic principles, making it common knowledge that does not require empirical citation.