GP added to recipe 1 with the addition of protein- rich ingredients displayed the weakest inhibitory effects (Table 3). In this case, the CML content was reduced from 4.70 and 3.80 mg/kg muffin in recipes 1 with nonfat dry milk powder (R1M) and dry egg white powder (R1E) produced without addition of GP to 3.94 and 2.37 mg/kg muffin in those with addition of GP (R1 M + GP and R1E + GP). In fact, it is possible that interaction among the phenolic compounds and ingredients added to these samples might promote a negative synergism, minimising the inhibitory effect of GP. It is known that polyphenols are able to bind certain kinds of nutrients, such as proteins. The main mechanism behind polyphenol–protein binding is considered to be noncovalent interaction of the amino, hydroxyl, and carboxyl groups of protein with the gallate and hydroxylate benzol groups of polyphenols (Huang, Kwok, & Liang, 2004). Moreover, the polyphenols have a preference for proteins with a high level of the amino acid proline—such as caseins and the alpha-lactalbumin and beta-lactoglobulin found in dairy products. Although both baking powder and salt increase the pH of the system, PCs from GP were more stable than in samples with protein-rich ingredients, which resulted in significantly higher reductions in CML content, from 13.30 and 9.98 mg/kg muffin (recipe 1 with baking powder (R1B) and salt (R1S) produced without addition of GP) to 0.89 and 1.77 mg/kg muffin (recipe 1 with baking powder (R1B + GP) and salt (R1S + GP) made using GP) (Table 3).