Recent innovations of ultrasound green technology in herbal phytochemistry: A review.

Ultrasound (US) has become one of the most important techniques in green chemistry and emerging technologies. Many research investigations documented the usefulness of US in a wide range of applications in food science, nanotechnology, and complementary medicine, where effective extraction of natural products is important. However, as with all novel technologies, US has advantages and limitations that require clarification for full adaptation at an industrial scale. The present review discusses recent applications of US in herbal phytochemistry with the emphasis on US effects on chemical structures of bioactive compounds extracted from herbs and their bioactivities. The impact of different US processing conditions such as frequency, intensity, duration, temperature, and pressure on the effectiveness of the extraction process and the properties of the extracted materials are also discussed. Different frequencies and intensities of US have demonstrated its potential applications in modifying, determining, and predicting the physicochemical properties of herbs and their extracts. US has important applications in nanotechnology where it supports the fabrication of inexpensive and eco-friendly herbal nanostructures, as well as acoustic-based biosensors for chemical imaging of the herbal tissues. The application of US enhances the rates of chemical processes such as hydrolysis of herbal fibers, which reduces the time and energy consumed without affecting the quality of the final products. Overall, the use of US in herbal science has great potential to create novel chemical constructions and to be used as an innovative diagnostic system in various biomedical, food, and analytical applications.

Oxidation induced by dielectric-barrier discharge (DBD) plasma treatment reduces soybean agglutinin activity.

In this study, potential of dielectric-barrier discharge (DBD) plasma treatment (40 kV, 12 kHz at 1, 2, 3 and 4 min) to eliminate soybean agglutinin (SBA) activity was investigated in a SBA model system and soymilk. The plasma treatment decreased the SBA in the model system and hemagglutination activity was decreased by 87.31%. SDS-PAGE analysis confirmed the degradation of the SBA polypeptide chain. The multi-spectroscopic analysis revealed a two-stage structure alteration in the SBA upon exposure to the plasma treatment. Oxidation of NH-/NH2- at the peptide bond disrupted the hydrogen bonds and altered the secondary structure of SBA. Further oxidation of aromatic amino acid, cleavage of peptide bonds and the breakage of polypeptide led to the SBA fragmentation and complete unfolding of the protein. The SBA inactivation by the plasma treatment was confirmed in soymilk. Plasma treatment is a promising technology for the elimination of SBA in soybean product.

Optimization of ultrasound assisted extraction method for phytochemical compounds and in-vitro antioxidant activity of New Zealand and China Asparagus cultivars (officinalis L.) roots extracts.

A two-level Plackett-Burman design with 8 variables was used to evaluate ultrasonic treatment variables influencing the total phenolic content (TPC) extracted from asparagus roots. Steepest ascent method was conducted to identify the significance of parameters such as extraction temperature, stirring speed, intermission time, extraction time, ultrasonic frequency, and ultrasonic power. Ethanol and methanol aqueous solutions were used as extraction solvents and solvent's concentration, extraction time, ultrasonic power and solid: liquid ratio were optimized in this study. A predicted value of TPC (71.1 mg/g) was obtained under the optimum conditions of extraction time 120 min, ultrasonic power 550 W, ethanol concentration of 20% and a solid: liquid ratio of 1:100. Central composite design was employed to further analyse the common interactions between the extraction variables and to further determine the optimal values that would generate the maximum TPC, total flavonoids content, total saponins content, caffeic acid and in vitro antioxidant activities. The optimal variables for ethanol extraction (80 min, 50% of ethanol, 360 W and 1:40) generated higher than methanol (410 W for 114.9 min using 73.7% methanol at 1:24).