Effect of ultrasonic and conventional extraction on bioactive components, glucosinolate content and antidiabetic activity of Crambe tataria.

This study was conducted to determine and compare the phenolic compounds, glucosinolate contents and antidiabetic effects of the extracts obtained by ultrasonic and conventional extraction method of the leaves and flowers of the Crambe tataria. The highest antioxidant activity (12.95 mg/mL IC50 value) and total phenolic content (1313.57 mg GAE/100 g fw) were detected in the ultrasonic flower extract. In total flavonoid results, extracts obtained from the flower part of C. tataria had higher values than that of extracts obtained from the leaf part. The most abundant phenolic component in the flower extract was catechin. The highest catechin content in all samples was detected in the ultrasonic flower extract with a value of 374.37 mg/kg. Rutin was the dominant phenolic component in the leaf extract. Rutin values were 654.38 mg/kg and 757.30 mg/kg for conventional and ultrasonic extraction, respectively. In glucosinolate analysis, the highest glucoraphanin content was obtained in flower samples and by conventional extraction method (3466.84 mg/kg). The highest contents of sinigrin (689.97 mg/kg), glucotropaeolin (420.89 mg/kg), glucoerucin (357.27 mg/kg), glucoraphasatin (181.11 mg/kg) and gluconasturtin (66.07 mg/kg) were detected in ultrasonic flower extracts. The highest α-amylase and α-glucosidase enzyme inhibition effects belonged to the ultrasonic flower extract with values of 3.70 mg/mL and 4.89 mg/mL, respectively. As a result, this study determined for the first time that ultrasonic extraction of C. tataria flowers has much higher bioactive components and antidiabetic effects, revealing the potential use of this plant in the fields of medicine, pharmacology and chemistry.

Reduction of bitterness in green walnuts by conventional and ultrasound-assisted maceration.

The efficiency of conventional and ultrasound-assisted maceration was investigated in comparison to reduce the bitterness of green walnuts. Conventional maceration was studied at room temperature for 6, 8 and 10 days while ultrasound-assisted maceration (20 kHz, %100 of amplitude) was performed at 36 °C for 6, 8, 10, 12, and 14 h. Phenolic content and antioxidant activity of green walnuts were decreased by reduction of bitterness. Phenolic content and antioxidant activity of green walnut jams prepared from debittered green walnuts by ultrasound-assisted maceration were higher than those of conventional maceration excluding ellagic acid only. Based on findings of sensory analyses, bitterness level was similar in green walnut jams prepared by ultrasound-assisted maceration for 12 h and conventional maceration for 6 days. On the other hand, green walnut jams processed by ultrasound-assisted maceration for 12 h led to the highest general acceptance. It was concluded that ultrasound-assisted maceration may provide better nutritional and sensory quality in green walnut jam. In addition, the time required for reduction of bitterness may be shortened from days to hours by ultrasound-assisted maceration.