Enzymatic hydrolysis as a valorization strategy of bovine lungs: Optimization of process variables and study of antioxidant capacity

Abstract

Background

The increase in meat production would also imply an increase in the generation of by-products or edible offal. These by-products can be used, due to their high protein content, as a substrate to obtain hydrolysates with functional activities. This study aimed to valorize bovine lungs by producing hydrolysates with antioxidant capacity.

Results

A response surface methodology study was carried out using a central composite design in which factors were temperature (43.2–76.8°C), enzyme/substrate ratio [ES: 0.65–4.85% (w/w)] using Alcalase 2.4 L/Flavourzyme (1:1) and pH (5.8–9.2). The antioxidant capacity of the obtained BLH (bovine lung hydrolysates) was evaluated by the ABTS, DPPH, and FRAP methods. The maximum antioxidant capacity was achieved at 53.°C, ES ratio of 2.3% (w/w), and pH of 8.2. Under optimal hydrolysis conditions, the antioxidant capacity increased rapidly from the beginning of the reaction to 30 min, reaching a maximum at 120 min; then, it decreased until the end (180 min). The degree of hydrolysis increased as hydrolysis occurred up to a maximum of 45%. Molecular weight distribution of BLH evaluated by Tricine-SDS-PAGE and SEC-FPLC showed that bovine lung proteins hydrolyzed for 120 min presented low molecular weight peptides (<5 kDa), which are absent in the non-hydrolyzed sample.

Conclusion

In this work, we optimized the variables for producing BLH with antioxidant capacity using commercial proteases in a short reaction time, making it a worthwhile strategy for the recovery of by-products from the meat industry.