## 4 Discussion
Participants were also asked to abstain from cigarette smoking and had access to water. The study meal design and the time intervals differed from our study, irrespective of the similar results obtained [60]. In a single study concerning the plasma antioxidant capacity of 13 healthy volunteers aged 40-70 years after oat or barley muffin consumption, no changes were observed after the interventions. The subjects received 48 g of whole grain in two small muffins. The flour used was either whole oat flour, whole barley flour, or refined wheat flour. There was a 1-week washout period between interventions. During each intervention, an oral glucose tolerance test was performed on each participant for 3 h following the consumption of a glucose reference (75 g in 300 mL water) along with the muffins. Each muffin provided 48.7 g flour, 8.2 g fat, 7.8 g protein, and 52.4 g carbohydrates (310 kcal). Blood samples were collected at baseline after 12 h fasting and at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46  
4, 6, 8, 10, and 24 h after meal administration. The study design and intervention meals differed from ours, although similar results in TAC were obtained [61]. Our results are in accordance with the general glycemic, lipid, and antioxidant capacity responses observed in a number of the previously mentioned studies, although the contradictory findings generally observed in the literature could be explained by the different solubility and molecular weights that characterize \(\beta\)-glucans, which has a direct effect on intestinal viscosity. Greater intestinal viscosity could potentially lower bile acid absorption and, thus, serum cholesterol levels [62; 63]. Additionally, intestinal viscosity has been proposed to be affected by methods of processing and the food matrices of \(\beta\)-glucan-enriched products [64]. Also, it has been reported that \(\beta\)-glucan could be degraded by endogenous enzymes present in barley and wheat flour during baking [58], which could be the case for the no-added effect we observed during our study. In fact, [PERSON] et al. demonstrated that baking can result in the enzymatic degradation of \(\beta\)-glucan [65]. Taking this into account, it could be challenging to predict the effect of \(\beta\)-glucan-enriched products on cholesterol levels. Furthermore, [PERSON] et al. reported a non-significant reduction in serum LDL cholesterol levels per gram of \(\beta\)-glucan incorporated into bread and cookies [64]; although, when \(\beta\)-glucan was incorporated either into fruit juice, fruit drink, or oat milk, the decrease was significantly greater. The authors suggested that \(\beta\)-glucan potential increases when incorporated into liquid products, which was also supported by further studies [63; 64; 66]. It was also reported that during the baking of bread or cookies, \(\beta\)-glucan becomes less viscous than raw \(\beta\)-glucan. This reduced viscosity was linked to a reduction in the ability of \(\beta\)-glucan to modify glucose and cholesterol absorption in the gastrointestinal tract [64]. In terms of antioxidant capacity status, relatively small phenolic compound concentrations found in bakery products and their interactions with dietary fibers such as \(\beta\)-glucan may be insufficient to increase antioxidant status and attenuate glucose-induced metabolic stress. Other authors have suggested that there may be only a minor or negligible effect on biomarkers of oxidative stress or antioxidant activity in response to whole grain cereal consumption [61; 67]. Therefore, the processing of whole grains and bakery products could alter the fibers' and phytochemicals' natural structure and content in a way that makes them less effective in attenuating cardiometabolic risk factors than originally expected [64].