The samples coded as R1A + GP (recipe 1 with all ingredients together produced with addition of GP) formed the most distinct cluster, which was linked to the other cluster at a large distance, indicating a significant difference. These samples were characterised by the highest amount of phenolic compounds, and the smallest (below LOD) levels of CML. The inhibition of free-radical generation derived from the glycation process and the subsequent inhibition of protein modification LY294002 is considered

one of the mechanisms of the antiglycation effect. Wu and Yen (2005) reported that flavonoids suppress fluorescence in the order flavones (luteolin) > flavonol (kaempferol, quercetin, and rutin) > flavanol (catechin, EC, ECG, EGC, and EGCG) > flavanone (naringenin). They suggested that the hydroxyl group at the C-3’ position contributed to the inhibitory activity of these compounds on AGE formation. According to Peng et al. (2008), the antiglycation properties of catechin, procyanidin B2, and epicatechin are not only the result of their antioxidant activities, but are also related to ability to trap reactive carbonyl species, such as methylglyoxal (MGO), which is an intermediate reactive carbonyl in AGE formation. GP added to the samples made according to Obeticholic Acid R2 displayed

the strongest inhibitory effect, but showed a common PC profile (Table 3). Despite the high level of CML in the R2 samples, the concentration of CML drastically decreased below the limit of detection when GP was added. The estimation of the antioxidant activity of plant phytochemicals added to food cannot be based only on the activities of a particular compound; on account of interactions, accompanying compounds should also be taken very into account. For example, additive effects were observed in mixtures containing catechin and ascorbic acid or α-tocopherol, whereas in the presence of sulphur dioxide, a synergistic effect was seen (Saucier & Waterhouse, 1999). In this way might arise the strong inhibitory effect of GP added to the oil-formulated muffins, rich in tocopherols. Clearly, the particular ingredients, as well as PCs

from GP, play important roles in the reduction of CML levels; however, the influence of all the ingredients on the viscoelastic properties of the product should also be taken into account. Modifying the pore structure in the crumb by adding ingredients might potentially contribute to variations in CML content, through changes in the migration of water and temperature. In conclusion, ingredients such as protein-rich compounds, baking powder, salt, and various types of sugar and plant oil have a substantial effect on CML content. The individual ingredients added to R1 significantly reduced CML content, while the addition of all the ingredients to R1 led to the highest reduction in CML—suggesting a synergistic effect between all the ingredients in the muffin formula.