Optimization of enzyme-assisted aqueous extraction of phenolic compounds from pistachio green hull

Phenolic compounds, especially those of plant origin, constitute an essential part of the human diet, and are of considerable interest due to their antioxidant properties. In this study the effect of enzymes (pectinase, cellulase and tannase) treatments on the extraction of phenolic compounds from the pistachio green hull was investigated. Optimization was carried out by changing one- factor-at-a-time, using four variables, time (1-5 h), solid to solvent ratio (1:20, 1:40, 1:80, 1:100, 1:150 w/v), particle size (smaller than 0.4 , between the 0.4-0.595 and 0.595-1 and larger than 1 mm) and enzyme dosage of pectinase (P) (0, 1.9, 3.8 and 7.6 U/ml), cellulase (Cl) ( 0, 1.25, 2.5 and 5 U/ml) and tannase (T) (0, 0.1, 2 and 8 U/g). Each enzyme significantly enhanced the amount of phenolic compounds extracted from the pistachio green hull. The optimum parameters were obtained as follows: pectinase (3.8 U/ml), cellulase (2.5 U/ml), tannase (8 U/g), time (4 h), particle size (0.4˃ mm), and solid to solvent ratio (1:80). Results indicate that a mixture of enzymes able to increase the total phenol, by 112.48%, compared to the controls (p < 0.05). Using a mixture of enzymes compared to the use of an enzyme increase the efficiency of extraction of phenolic compounds. For example, using a mixture of PClT enzymes can increase the total phenol by 22.25%, 18.26% and 14.91 %, respectively, compared to P, Cl and T.

کلیدواژه ها:

enzyme-assisted extraction ، Cellulase ، Pectinase ، Tannase.