# Assessment of the Possibility of Using Poppy Seed Cake for the Production of Oat Cookies
## 4 Discussion  
It can be assumed that reducing the moisture content of oat cookies with an increase in the poppy seed cake content is associated with the higher water absorption capacity of cereal flakes. As reported in the literature, water absorption determined with the centrifuge method (measuring the amount of liquid that can be centrifuged under set conditions from ground grain homogenate with added water) may be as high as 119% [21]. In the case of oilseed cake, the value of this parameter ranges from 10 to 25% [22]. In other studies [23; 24] describing the quality of bread with the addition of oilseeds, lower crumb moisture was also found for the supplemented samples compared to the control sample. Changes in the protein, fat, and fiber contents were caused by the substantially higher contents of these components in poppy seed cake than in oats, which was partially confirmed by [PERSON] et al. [25] and [PERSON] and [PERSON] [13]. In the research, the authors determined the contents of protein and fat in poppy seed pomce [13] and oat grain [24]. The analyses showed that the blue poppy pomce contained over 28% crude protein, while the hull-less oat grain contained less than 13%. However, the poppy seed cake analyzed by [PERSON] and [PERSON] [13] contained a lower amount of fat (2.32-4.28%) than oat grain (4.82%), but it should be noted that the poppy seeds defatted by [PERSON] and [PERSON] [13] were cold-pressed and then the cake was slurred in hexane three times (to remove the remaining oil). In our experiment, poppy seed cake was obtained only by cold-pressing, so it had a higher amount of fat. In is noteworthy that there were no significant changes in the contents of glucose and fructose along with the increase in the poppy seed cake dose from 5 to 10%. Oilseed cake is generally characterized by a lower carbohydrate content than that in cereal grains [6; 12; 26]. Hence, the use of oilseed or cake to fortify cereal products results in a reduced content of carbohydrates in their composition [4; 27]. Literature data confirm that oilseeds are a valuable source of antioxidants. For instance, the total phenolic content in raw poppy seeds is approximately 332 mg\(\cdot\)100 g\({}^{-1}\)[15]. However, it can be assumed that these compounds were lost during the pressing process  
Figure 2: Sensory evaluation of oatmeal cookies with poppy seed expeller added: C—control probe, PC5—oatmeal cookies with 5% poppy seed expeller added; PC10—oatmeal cookies with 10% poppy seed expeller added; PC15—oatmeal cookies with 15% poppy seed expeller added. and were part of the extracted oil [28]. Hence, the contents of flavonoids and polyphenols in the products we studied were quite low. The textural research results are consistent with the findings shown in other reports [29,30] on the properties of other cereal products fortified with seed cake. Analogous changes in the textural properties were observed in the experiment conducted by [PERSON] et al. [29] in which bread was supplemented with hemp seed cake. The authors reported significant increases in hardness and chewiness and decreases in elasticity and cohesiveness caused by the addition of hemp seed cake. The hardness could be greatly influenced by the composition of the flour. There were positive correlations between fiber and protein and the hardness values of cookies [30]. It is also possible that there is an influence of the particle size of the poppy expeller, and hence its hardness, on the texture of the final product. Previous studies have shown the effect of particle size on the texture properties of cereal products [31]. As shown in the study conducted by [PERSON] et al. [29], elasticity changed significantly only in the 20% supplementation variant. The same trend in the changes in mechanical properties was also found in a study on the supplementation of buns with coconut residue [32]. The significant changes in the color parameters of the different oat cookie probes were mainly caused by the characteristic dark color of the poppy seeds.