Ultrasound-assisted extraction (UAE) was applied for the extraction of bioactive valuable compounds from winter melon (Benincasa hispida) seeds. Effects of amplitude (25-75%), temperature (40-60°C) and sonication time (20-60 min) on crude extraction yield (CEY) and radical scavenging activities (RSA, % inhibition of DPPH˙ and ABTS˙+ free radicals) of extracts were determined using complete randomised design (CRD). The results showed that the CEY and RSA of extracts significantly affected by independent variables. The maximum value of CEY (97.14±0.36 mgg-1), scavenging of DPPH˙ radicals (32.12 ± 0.38%) and scavenging of ABTS˙+ radicals (40.52±0.73%) were obtained at the combined treatment conditions of 75%, 55°C and 40 min. The UAE results obtained were compared with those achieved by using conventional Soxhlet extraction (CSE) method. It was found UAE allowed extraction at lower temperature and the extracts obtained posses higher quality compare with CSE. UAE is a promising environment friendly technique for the extraction of bioactive compounds from winter melon (Benincasa hispida) seeds.
This study aimed to investigate the effects of the ultrasound-assisted extraction conditions on the yield, specific activity, temperature, and storage stability of the pectinase enzyme from guava peel. The ultrasound variables studied were sonication time (10-30 min), ultrasound temperature (30-50 °C), pH (2.0-8.0), and solvent-to-sample ratio (2:1 mL/g to 6:1 mL/g). The main goal was to optimize the ultrasound-assisted extraction conditions to maximize the recovery of pectinase from guava peel with the most desirable enzyme-specific activity and stability. Under the optimum conditions, a high yield (96.2%), good specific activity (18.2 U/mg), temperature stability (88.3%), and storage stability (90.3%) of the extracted enzyme were achieved. The optimal conditions were 20 min sonication time, 40 °C temperature, at pH 5.0, using a 4:1 mL/g solvent-to-sample ratio. The study demonstrated that optimization of ultrasound-assisted process conditions for the enzyme extraction could improve the enzymatic characteristics and yield of the enzyme.
The key purpose of this experiment was to evaluate the thrombolytic, antioxidant, membrane stabilizing and antimicrobial potentials of crude ethanol extracts (CEE) of whole plant, organic and aqueous soluble fractions (OF & AQSF). CEE showed the highest (44.63%) clot lysis activity compared to streptokinase (64.35%). In DPPH study, petroleum ether soluble fraction (PSF) has exhibited IC50 of 18.83 μg/mL while the standard ascorbic acid was 2.48 µg/mL. AQSF profoundly inhibited the lysis of erythrocytes (66.20%) which was insignificantly different (p > 0.05) to acetylsalicylic acid (71.98%), the reference. However, AQSF showed a significantly stronger level of protection against heat-induced hemolysis (64.80%) as compared with the acetylsalicylic acid (78.90%). CEE, OF and AQSF have displayed reasonable growth of inhibition of tested bacteria compared to negative control and standard drug (77.50 mg of GAE/g).