Background: In modern society, there is a tendency to consume products with natural origins and minimum chemical additives. This has encouraged the replacement of synthetic antioxidants for the ones obtained from natural sources, such as the antioxidants acquired from enzymatic protein hydrolysates. Objective: In this study, the process of enzymatic hydrolysis of proteins from bovine plasma, which produces hydrolysates with an antioxidant capacity (AC), was scaled up from 1 to 5 L. Methods: An experimental design was developed in 1 L to evaluate the effect of the substrate concentration (So) on the time needed to reach a Degree of hydrolysis (DH) of 20 % as well as the AC. Results: The best conditions in the 1 L reactor controlled by a Titrando 842, were transferred to 5 L in a BioFlo310 reactor. These conditions were achieved at a ratio of 80 g/L of substrate and 0.89 AU of Alcalase 2.4L/g of substrate in order to obtain level of 16.36 ± 0.21 min of the 20 % of DH and an antioxidant capacity of 58.98 ± 1.80 %. Conclusion: The results showed that while DH depends on So, the antioxidant capacity only depends on the DH. Additionally, the dimensional analysis using Re as a scaling criterion obtain allowed us to obtain the same results in the model (1 L) and the prototype (5 L).

Protein hydrolysis can improve food's nutritional, techno-functional and biological properties, which can increase the possibilities of application in industry. The objective of this research article was to study the effect of lipids on the enzymatic kinetics of red tilapia viscera (RTV) hydrolysis with subtilisin Carlsberg. The RTV were hydrolyzed in an enzyme/substrate ratio of 0.153 (U/g), at 53° C, at a pH of 9.5, initial concentrations of lipids of 1, 19 and 50 g/L, and different initial substrate concentrations for each initial lipid concentration. To explain the lipid action mechanism, we evaluated a Michaelis-Menten model and another semi-physical model based on kinetic expressions and mass balances. Additionally, a molecular docking analysis was performed between subtilisin Carlsberg and the main fatty acid in RTV (palmitic acid). For both models, the results suggest a strong competitive inhibition by lipids, with an inhibition constant of 2.36 and 3.01 g/L for the first and second models, respectively. On the other hand, docking suggested that palmitic acid could form van der Waals interactions and hydrogen bonds with the residues of the active site of subtilisin Carlsberg and occupy part of the substrate binding site, thus acting as an effective competitive inhibitor.