## 3 Results
### Muslroom DFI Water and Oil Retention Capacity  
The water retention capacity (WRC) of mushroom DFI is shown in Table 4. WRC ranged from a minimum of 4.2 g water/g of DFI to a maximum of 21.3 g water/g of DFI. The highest WRC values obtained for the mushroom DFI are higher than that obtained for dietary fiber concentrates obtained from orange, peach, artichoke and asparagus, mango peel, sugar beet (10-14 g/g), apple and pear (6-7 g/g) and much higher than that observed for wheat and oat bran, carrot, and pea dietary fiber concentrates (3-4 g/g) [59; 60; 61] and in the range of that observed for potato fiber (23-25 g/g) [62]. As can be observed in Figure 4a, the WRC of the mushroom DFI was strongly dependent on \(T\), being observed a decrease in the WRC with increasing \(T\), whatever the \(C_{H_{2}O_{2}}\).  
For the \(C_{H_{2}O_{2}}\) there was observed a minimum for the WRC at the central value of this factor, with lower and higher levels showing a positive effect in the WRC of the DFI. For the \(C_{NaOH}\) there were observed to different situations (Figure 4b), for lower treatment times there was observed an increase in the WRC with increasing \(C_{NaOH}\), the reverse was true for higher treatment times. Keeping the level of factor \(T\) at the minimum, the effect of \(C_{NaOH}\) on the WRC of DFI was much more important than the \(C_{H_{2}O_{2}}\) (Figure 4c). Whatever the \(C_{H_{2}O_{2}}\) the higher WRC was observed for the higher \(C_{NaOH}\). For a higher WRC of the DFI the optimum \(C_{H_{2}O_{2}}\) level was 1.682, the \(C_{NaOH}\) level should be 1.682 and the level for factor \(T\) should be \(-1.682\) (predicted WRC of 36.0 g/g of DFI with a 95% prediction interval of 29.6 to 42.4 g/g).  
The oil retention capacity (ORC) of mushroom DFI is shown in Table 4. ORC varied from a minimum of 6.0 g oil/g of DFI to a maximum of 18.9 g oil/g of DFI. The ORC values obtained for the mushroom DFI were higher than that obtained for dietary fiber concentrates obtained from apple, pea, wheat, carrot (1-2.3 g/g) and sugar beet (5 g/g) [59], apple pomace and citrus by-products (0.6-1.8 mL oil/g) [63], unripe banana flour (\(\sim\)2 mL oil/g) [64]; carrot pulp dried at 50 \({}^{\circ}\)C (\(\sim\)6 mL oil/g) [65] and asparagus by-products (5.5-8.5 mL oil/g) [66]. As can be observed in Figure 5a, the ORC of the mushroom DFI was strongly dependent on the \(C_{H_{2}O_{2}}\) and \(T\), being observed the higher value of ORC for lower \(T\) and higher \(C_{H_{2}O_{2}}\).  
The same effect was observed for factor \(C_{NaOH}\), for lower \(T\) there was observed an increase in the ORC with increasing \(C_{NaOH}\), the reverse was true for high \(T\) (Figure 5b). When the effect of the factors \(C_{NaOH}\) and \(C_{H_{2}O_{2}}\) are represented, there was observed that the maximum ORC was obtained or for high \(C_{NaOH}\) and \(C_{H_{2}O_{2}}\) when the treatment time was at the lower level (Figure 5c) the reversed being observed for longer treatment times (result not showed). Using the factor levels where the maximum value is observed (\(T=-1.682\); \(C_{H_{2}O_{2}}\) and \(C_{NaOH}=1.682\)) the predicted value of ORC of the DFI is 35.8 g/g of DFI (95% prediction interval between 30.8 to 40.8 g/g).  
Figure 4: Response surfaces for mushroom DFI water retention capacity (WRC) as a function of: (**a**) time and hydrogen peroxide concentration (at sodium hydroxide concentration level of 1.682); (**b**) time and sodium hydroxide concentration (at hydrogen peroxide concentration level of 1.682); (**c**) hydrogen peroxide concentration and sodium hydroxide concentration (at time level of \(-1.682\)).