Pectinase and naringinase help to improve juice production and quality from pummelo (Citrus grandis) fruit

Pectinase and naringinase were investigated for improving the production of pummelo juice by increasing the juice yield and eliminating juice bitterness. Compared to a control, the enzymatic treatment significantly (p<0.05) increased the juice yield, soluble pectin and total soluble solid (TSS) contents, and the clarity, while decreasing the concentrations of the bitter chemicals naringin, limonin, and nomilin. A combined processing treatment of peeling and enzymatic hydrolyses using 5U/g of pectinase and 0.4 U/g of naringinase at 50oC for 60 min resulted in a juice yield of 42.3%, a TSS content of 11.4oBx, a titrable acidity (TA) of 0.96%, a vitamin C concentration of 38.4 mg/100 mL, and concentrations of naringin, limonin, and nomilin of 42.4 μg/mL, 33.5 μg/mL, and 13.3 μg/mL, respectively. The enzymatic method was effective and practical for production of high quantity pummelo juice.