Optimization of the Extraction of Antioxidant Compounds from the Depleted Substrate of Pleurotus ostreatus Using Ultrasound as a Valorization Alternative

Objective: This study optimized the ultrasonic extraction of bioactive compounds from spent Pleurotus ostreatus substrate by response surface analysis, evaluating the effect of extraction conditions on a corn plant waste-based substrate. Theoretical Framework: Mushroom production for human consumption generates poorly utilized by-products that are highly relevant due to the compounds they contain. Unfortunately, not enough information has been generated on their extraction. Method: Three extraction parameters were varied: amplitude (X1) (20 and 100%), extraction time (X2) (5 and 15 minutes) and methanol concentration (X3) (10 and 30%), evaluating the content of total phenols, total flavonoids, tannins and antioxidant capacity through the inhibition of ABTS and DPPH. Results and Discussion: For total phenols, the best conditions were X1=100%, X2=10 min, X3=10%. The best extraction conditions for tannins were X1=20%, X2=10 min and X3=30% MeOH, for the antioxidant capacity for DPPH and ABTS were X1=60%, X2=5 min, X3=30% MeOH and X1=100%, X2=5 min, X3=10% MeOH respectively. Through the analysis, the optimum extraction was found X1=85%, X2=11.26 min, X3=10% MeOH, and when the predicted values ​​were compared with the experimental ones, similarities of up to 99% were found for flavonoids between what was predicted and what was experimental. Research Implications: Using spent substrate from P. ostreatus is an effective alternative for obtaining compounds with biological activity. Originality/Value: This study contributes to generating an alternative for the comprehensive use of by-products derived from the P. ostreatus industry.