ResumenEn este trabajo se optimizó la reacción de hidrólisis enzimática de proteínas de la fracción globular de sangre bovina usando la metodología de superficie de respuesta. Se evalúo el efecto de la concentración de sustrato (S0: 8-12 %), la relación enzima/sustrato (E0/S0: 4-12 g/100 g proteína) y el pH (8-10), sobre el grado de hidrólisis (GH), en un reactor Batch (temperatura de 55° C, por 2 h). La optimización del modelo estadístico obtenido entregó un máximo GH de 38,08 % para pH: 8,16; S0: 6,6 y E0/S0: 14,7, el cual fue corroborado experimentalmente dando un GH de 36,25 ± 0,3 con sesgo negativo de 5 %. A estas condiciones se tomaron muestras a tres tiempos de hidrólisis para evaluar la capacidad antioxidante, con los métodos químicos conocidos como ORAC, ABTS y FRAP. Se alcanzó mayor capacidad antioxidante a mayor tiempo de hidrólisis. Después de una digestión in vitro se corroboró que la capacidad antioxidante del hidrolizado se conserva.Palabras clave: péptidos bioactivos; hidrólisis enzimática; actividad antioxidante; sangre bovina; proteína Optimization of Enzymatic Hydrolysis of Bovine Blood Cell Fraction by Response Surface Methodology (RSM) and Evaluation of its Antioxidant Properties AbstractIn this paper the reaction of enzymatic hydrolysis of the erythrocyte fraction of bovine blood was optimized through the response surface methodology. The effects of substrate concentration (S0: 8-12 %), enzyme/substrate ratio (E0/S0: 4-12 g/100 g protein) and pH (8-10), on degree of hydrolysis (DH) working to constant temperature of 55° C in a batch reactor, by 2 h were determined. The optimization of the statistical model obtained gave a maximum DH of 38.08 %, with pH 8.16; S0: 6.6 and E0/S0: 14.7, which was experimentally proved giving a DH of 36.25 ± 0.3 with negative bias of 5 %. At the optimal conditions samples were taken at three hydrolysis times to evaluate the antioxidant capacity, which was analyzed with ORAC, ABTS and FRAP methods. Greater antioxidant capacity was obtained at long hydrolysis time. After in vitro digestion it was confirmed that the antioxidant capacity of hydrolyzate remained.

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The increasing nutraceutical market has led to the interest in multidisciplinary research for new insights on the discovery, design, and development of nutraceuticals. In the last decades, enzymatic hydrolysis of food proteins has given added value to food byproducts, such as whey, fish byproducts, collagen, and other food byproducts containing proteins (de Castro & Sato, 2015). Through enzymatic hydrolysis, different health effects have been attributed to derived peptides, including antimicrobial properties, blood pressure lowering effect, cholesterol lowering ability, antithrombotic and antioxidant capacity, enhancement of mineral absorption, immunomodulatory effect, and opioid activities (Jamdar et al., 2010). Among the bioactive peptides resulting from protein hydrolysis, antioxidant peptides play a key role in the market as antioxidant natural products.As a by-product, whey disposal may cause environmental issues; thus, it is necessary to valorize whey to generate value-added products for the food industry (Lappa et al., 2019). Whey can be used