# Effect of Microwave-Assisted Processing of Acorn Flour on Muffin Quality
## 3 Results and Discussion
### Effect of Microwave-Treated Acorn Flour Addition on Antioxidant Properties of Muffins  
The incorporation of microwave-treated acorn flour into wheat-acorn muffins influenced the content of free phenolic compounds, flavonoids, and tannins, as well as the antioxidant capacity (Table 5). These changes were dependent on the duration and power of microwave treatment, following a linear trend: longer microwave treatment durations and higher power levels resulted in increased content of phenolic compounds and flavonoids, as well as enhanced antioxidant capacity, while the tannin content decreased. The incorporation of acorn flour, even in its raw form, results in an increase in the antioxidant content of the final product, owing to the naturally high levels of antioxidants present in acorns and their derived products. [PERSON] et al. [80] observed an over seven-fold increase in the total free phenolic compound content in wheat bread enriched with acorn flour. Similarly, [PERSON] et al. [51] reported an eighteen-fold increase in phenolic compound content in Iranian toasted wheat bread containing 30% acorn flour compared to the control sample. [PERSON] et al. [81] found that the total free phenolic compound content was 1.5 times higher in gluten-free bread with 25% acorn flour than in the control sample. [PERSON] et al. [82] documented a 2-fold increase in total phenolic compound content, a 7-fold increase in ortho-diphenyl, and approximately a 1.5-fold increase in flavonoid content in gluten-free bread with 35% acorn flour compared to control samples. However, available studies on the use of acorn flour in cake and muffin production [60; 71; 77; 78]do not provide information regarding the phenolic compound content or antioxidant properties of the resulting products. The content of phenolic compounds and flavonoids in muffins baked with the addition of microwaved acorn flour was significantly lower than in the flour itself. As acorn flour was one of the recipe ingredients, it contributed to a substantial reduction in the concentration of antioxidant compounds in the final product. Furthermore, the impact of high temperatures during baking must be considered as these can lead to the degradation of phenolic compounds and flavonoids, which are known for their low thermal stability [44; 83]. Microwave treatment of acorn flour influences the enhancement in antioxidant properties and the reduction in antinutritional compounds in muffins (Table 5). This effect results from the changes occurring in the flour during microwave processing, as outlined in Table 2. Notably, in muffins--unlike in flour--the content of free phenolic compounds and flavonoids increased linearly, with no decrease in the concentration of these compounds even with prolonged microwave treatment. In addition to the microwave processing of the flour used in the formulation, the baking process itself may also affect the phenolic compound content in muffins. [PERSON] and [PERSON] [84] demonstrated that during the preparation and baking of muffins made from blends of hairless canary seed, wheat, and corn, the content of bound phenolic acids decreased while the content of unbound phenolic acids increased. As sugar is incorporated into the muffin batter, the increase in antioxidant properties may result not only from the release of phenolic compounds from their bound form but also from the Maillard reaction. This reaction, occurring under high temperatures during baking, leads to the formation of compounds with strong antioxidant properties, such as melanoidins [85; 86]. \begin{table}