Ultrasonics Sonochemistry最新文献

This study aimed to optimize the ultrasonic-enzyme-assisted deep eutectic solvent extraction (UEADESE) Abelmoschus manihot (L.) leaves flavonoids (AMLF) and elucidate the underlying mechanisms. Screening of extraction parameters was first performed via single-factor experiments, followed by optimization using response surface methodology (RSM). A back-propagation (BP) neural network coupled with a genetic algorithm (GA) was constructed to compare its predictive performance with that of RSM. Under the optimal extraction conditions determined as follows: molar ratio of choline chloride to 1,4-butanediol (1:6), 30% water content, 2.4% (w/w) cellulase-xylanase (total enzyme concentration), a mass ratio of cellulase and xylanase 1:3 (w/w), 1:50 (g/mL) solid-liquid ratio, 44 min ultrasonic treatment time, 180 W ultrasonic power, the maximum total flavonoid extraction yield was achieved at 37.54 mg/g. Molecular dynamics simulations revealed that flavonoids were anchored within DES nano-clusters via a persistent hydrogen-bond network, which enhanced solubility while inhibiting thermal degradation of redox-active hydroxyl/glycosidic moieties. Fourier-transform infrared (FT-IR) analysis confirmed that the formation of hydrogen bonds between deep eutectic solvent (DES) and flavonoids contributed to a marked enhancement in extraction efficiency. Antioxidant assays (DPPH, ABTS, hydroxyl radical scavenging, and total reducing power) demonstrated that UEADESE extracts exhibited significantly higher antioxidant activity than conventional solvent extracts. These findings validate UEADESE as a sustainable and effective method for efficiently extracting AMLF while preserving its antioxidant activity, thereby laying a scientific foundation for its potential application in functional food development.

Energy efficiency and process control are critical challenges in scaling sonochemical applications. To address this, we introduce a numerical optimisation framework focused on designing pre-seeded bubble clusters driven by impulse ultrasound to minimise energy consumption. The methodology efficiently handles the large parameter space (bubble sizes) by combining fast, reduced-order modelling of spherical bubbles and chemical kinetics with expensive multi-phase hydrodynamic simulations (ALPACA). The technique is demonstrated on two test cases: ammonia (NH₃) and hydrogen (H₂) synthesis, to analyse the effects of different reaction mechanisms. In both cases, the optimal size distribution of a chain of 16 bubbles is found with as few as three multi-phase flow simulations.

Polysaccharides from water kefir grains (WG) are functional, food-safe, and potential novel materials for functional food development. This study focused on the extraction process, structural characteristics, and in vitro biological activities of polysaccharides from WG (WPU), as well as the effects of WPU on goat yogurt (GY). WPU was optimally extracted from WG via ultrasound-assisted extraction (UE) under the conditions: 340 W (ultrasonic power), 42 min (ultrasonic time), 20 mL/g (liquid-to-solid ratio), and 80 °C (ultrasonic temperature), achieving a high yield of 27.64%. The monosaccharide composition of WPU-4 (the main purified fraction) was glucose (96.59 mol%), arabinose (0.23 mol%), galactose (0.66 mol%), and mannose (2.52 mol%). Its backbone was predominantly composed of 6-Glcp. Scanning electron microscopy (SEM) revealed that WPU-4 exhibited a sheet-like structure, with an uneven and loose porous network on its surface and a honeycomb-like morphology in its interior. In vitro assays showed WPU had superior antioxidant, α-glucosidase, and pancreatic lipase inhibitory activities compared to purified fractions. Adding 1.0 mg/mL WPU to GY enhanced its antioxidant, antidiabetic, and hypolipidemic activities. This research provides an efficient WPU extraction method and confirms bioactivity potential, offering technical support for WPU industrial applications as functional ingredients in foods and pharmaceuticals.

Sonoluminescence, the light emission from bubbles undergoing large volume oscillations, has traditionally been associated with near-spherical bubble collapses in free liquid. In contrast, highly asymmetric bubble collapses near solid boundaries are known to cause surface erosion from transient and extreme pressure build ups. While both phenomena are caused from energy focusing during bubble collapse, a connection between erosion and light emission has not been previously reported. Here, we for the first time observe the highly asymmetric toroidal cavitation bubble collapse leading to erosive effects on the nearby boundary emits light, too. Through multi-modal measurements of the bubble dynamics and the associated phenomena near solid surfaces, we find that light emission occurs exclusively at the sites and time of the most intense flow focusing. Yet, we find no correlation between the occurrence of light emission from sonoluminescence and erosion. This findings reveal that the mechanisms governing energy focusing within the bubble and in the liquid are resulting from distinct energy focusing pathways.

Lotus seedpod is a by-product of Lotus seed planting industry with abundant polyphenols. This study optimized the ultrasonic-assisted extraction (UAE) parameters of hypolipidemic compounds from lotus seedpod by response surface methodology guided-by lipase inhibition activity (LPIA). The major active compounds were enriched and identified, the in vitro and in vivo lipid lowering effect was explored by cell and mice models. The optimized conditions were 69% ethanol aqueous solution, ultrasonic power of 300 W and time of 62 min, under which the total polyphenol (TPC) and total flavonoid content (TFC) reached 125.41 mg GAE/g DM and 361.82 ± 2.76 mg QUE/g DM, respectively, with pancreatic lipase inhibitory activity (PLIA) of 8.38 ± 0.20 mg DM/mL. Ethyl acetate was the suitable solvent for enriching the hypolipidemic fraction in lotus seedpod polyphenol extract (LSPE). LSPE exhibited promising lipase inhibition (IC₅₀ value = 171.5 μg/mL) and significantly decreased the lipid accumulation in 3 T3-L1 cells. Flavonoids, especially for quercetin and kaempferol derivatives, were the major compounds. In vivo assays indicated that LSPE treatment reduced weight gain and serum lipid level, and repaired liver damage by alleviating oxidative stress and inflammation in obese mice. These findings highlight the potential of lotus seedpod as a natural source of hypolipidemic actives, while also demonstrating the high efficiency of UAE in extracting plant-based hypolipidemic compounds.

Ultrasound and slightly acidic electrolyzed water (SAEW) treatments have been widely applied to enrich γ-Aminobutyric Acid (GABA) during the germination of grains and legumes; however, the effects and underlying mechanisms of their combined treatment on GABA enrichment remain unclear. After 72 h of germination, this study investigated the impacts of different treatment methods-distilled water treatment (GM), ultrasound treatment (UGM), SAEW treatment (SGM), and combined treatment (USGM)-on key enzyme activities, protein structural characteristics, and the GABA metabolic pathway in germinated mung beans. The results indicated that the combined treatment of ultrasound and SAEW promoted GABA enrichment in germinated mung beans, with the GABA content reaching 6.25 ± 0.025 mg/g. Additionally, it significantly enhanced the activities of glutamate decarboxylase (GAD), diamine oxidase (DAO), and polyamine oxidase (PAO) to 0.359 ± 0.008 U/g, 0.554 ± 0.021 U/g, and 1.265 ± 0.036 U/g, respectively (p < 0.05). Fourier-transform infrared spectroscopy and intrinsic fluorescence spectroscopy analyses revealed that the combined treatment significantly increased the content of α-helix and β-turn structures in the protein secondary structure (p < 0.05), while reducing the proportions of β-sheet and random coil structures, and enhanced protein surface hydrophobicity. Untargeted metabolomics analysis further demonstrated that the combined treatment significantly upregulated the levels of amino acid-related compounds, with a strong positive correlation observed between Glu and GABA content. Moreover, it primarily facilitated GABA synthesis by modulating pathways such as arginine-proline metabolism, arginine biosynthesis, alanine, aspartate, and glutamic acid metabolism, and butanoate metabolism. The findings of this study provide theoretical support for elucidating the molecular mechanisms by which ultrasound and SAEW promote GABA enrichment in mung beans and offer new insights for developing functional mung bean foods rich in GABA..