Degradation, isomerization and stabilization of three dicaffeoylquinic acids under ultrasonic treatment at different pH

Development of pH-adjusted NMR methodology for quantitation of caffeoylquinic acid derivatives and evaluation of their antimalignant pleural mesothelioma potential

Quantitative analysis of caffeoylquinic acids (CQAs) is challenging due to their structural similarities and susceptibility to isomerization and degradation. To overcome these limitations, a pH-adjusted quantitative 1H NMR (qHNMR) method is proposed for evaluating different CQAs in the extracts using a MeOD/HEPES-d18 buffer. This method was applied to measure the concentrations of chlorogenic acid (1) and 3,5-di-CQA (4) in Cuscuta japonica extract, and of chlorogenic acid (1) in green coffee bean extracts. A comparison of quantum mechanics (QM)-based and non-quantum mechanics-based approaches in qHNMR has shown that the application of QM-qHNMR improves the precision and sustainability of quantitative NMR. In addition, C. japonica extract and its isolated CQAs (1-7) were investigated for anticancer effects against NCI-H2452 cells, showing that methyl di-CQA esters (5 and 7) inhibit proliferation and induce apoptosis of NCI-H2452 cells, indicating their potential as therapeutic agents for treating malignant pleural mesothelioma.

Ultrasonic cavitation treatment of o-cresol wastewater and long-term pilot-scale study

Acoustic cavitation is a cutting-edge and eco-friendly advanced oxidation technology with significant efficacy in removing organic pollutants from water. Despite its potential, research on the degradation of o-cresol, a common and challenging phenolic pollutant, is limited. This study systematically investigates the optimal conditions for degrading o-cresol via acoustic cavitation and evaluates its application potential through extensive pilot tests. Batch test results indicate that ultrasonic cavitation effectively treats high concentrations of o-cresol (300 mg L-1), with aeration and neutral pH conditions enhancing removal efficiency, while the initial concentration has minimal impact on the removal rate. Additionally, analyses of total organic carbon (TOC), degradation products, and volatile organic compounds (VOCs) reveal that the main intermediates of o-cresol degradation through ultrasonic cavitation are substituted phenols and alkanes, with a mineralization rate reaching 60%. To assess the practical application of ultrasonic cavitation devices for o-cresol wastewater treatment, long-term pilot tests were conducted. These tests confirmed the device's effectiveness in removing o-cresol and its operational stability over 180 days. Furthermore, the study established the relationship between the o-cresol removal rate, hydraulic retention time (HRT), and operational cost. Consequently, this study demonstrates the feasibility of ultrasonic cavitation technology in treating high-concentration o-cresol wastewater and its potential for use in the pretreatment stage of biochemical treatment processes.

Treatment of high concentration phenol wastewater by low-frequency ultrasonic cavitation and long-term pilot scale study

Acoustic cavitation is an advanced, eco-friendly oxidation technology effective in removing organic pollutants from water. However, research on its use for degrading phenol, a common and challenging phenolic pollutant, is limited. This study explores the optimal conditions for phenol degradation using acoustic cavitation and assesses its practical application through extensive pilot tests. Results from batch tests show that low-frequency (15 kHz) ultrasonic cavitation effectively treats high concentrations of phenol (1000 mg L-1). Aeration and acidic pH enhance removal efficiency, while alkaline conditions inhibit degradation. Analysis of total organic carbon (TOC), degradation products, and volatile organic compounds (VOCs) reveals that the primary intermediates are substituted benzenes and alkanes. Long-term pilot tests demonstrated the device's effectiveness in phenol removal and its operational stability over 180 days. The study also establishes a relationship between removal efficiency, hydraulic retention time (HRT), and operating costs, highlighting the feasibility of low-frequency ultrasonic cavitation for treating high-concentration phenolic wastewater and its potential role in the pretreatment stage of biochemical processes.

An efficient PCN-224/graphene aerogel-based extraction method for monitoring the degradation of organophosphorus pesticides in juice

An efficient PCN-224/graphene aerogel modified silica (PCN-224/GA@Sil)-based extraction method was established for monitoring the degradation process of two organophosphorus pesticides (OPPs) in juice. PCN-224/GA@Sil exhibited higher surface area (307.35 m2 g-1) than graphene oxide modified silica (254.09 m2 g-1). The introduction of PCN-224 endowed the sorbent with excellent adsorption specificity towards OPPs due to the ZrˑˑˑS/O coordination bond. PCN-224 exhibited relatively higher theoretical adsorption energies of PCN-224 towards fenitrothion and fenthion were 0.68 eV and -0.31 eV. The established PCN-224/GA@Sil-HPLC method showed the linearity of 0.2-500 μg L-1 for analytes. The matrix effects in juice were 9.68 % and 3.61 % for fenitrothion and fenthion. Finally, it was used for the sample pretreatment of juice preventing interference from food matrices to monitor the degradation of two OPPs. A combination method of ultrasound and xenon lamp was adopted to degrade fenitrothion and fenthion displaying the synergistic effect (SE=2.12, 1.39).

Metabolomic monitoring of chicory during in vitro gastrointestinal digestion and correlation with bioactive properties

Chicory, recognized as a functional food, is increasingly becoming the focus of research. This study aimed to investigate the in vitro impact of gastrointestinal digestion on the composition and bioactive properties of chicory decoction. Chicory flour, derived from the roots, was transformed into an aqueous decoction and was subjected to simulated in vitro human gastrointestinal digestion (SGID). For the first time, the influence of the digestive process on specific classes of bioactive molecules was tracked across different digestive compartments (oral, gastric, and intestinal) using a metabolomic approach. Concurrently, the antioxidant, anti-inflammatory, and intestinal hormone regulation effects were assessed before and after SGID. The findings revealed that specific transformations of chlorogenic acid (CGA) and sesquiterpene lactones (STL) during SGID enhanced antioxidant and anti-inflammatory properties post-digestion. Quantitative results demonstrated a significant increase in ROS scavenging capacity and metabolite activity.

Characterization of ultrasound-assisted covalent binding interaction between β-lactoglobulin and dicaffeoylquinic acid: Great potential for the curcumin delivery

The low bioavailability and poor gastrointestinal instability of curcumin hampers its application in pharmaceutical and food industries. Thus, it is essential to explore efficient carrier (e.g. a combination of polyphenols and proteins) for food systems. In this study, covalent β-lactoglobulin (LG)-dicaffeoylquinic acids (DCQAs) complexes were prepared by combining ultrasound and free radical induction methods. Covalent interactions between LG and DCQAs were confirmed by analyzing reactive groups. Variations in secondary or tertiary structure and potential binding sites of covalent complexes were explored using Fourier transform infrared spectroscopy and circular dichroism. Results showed that the β-sheet content decreased and the unordered content increased significantly (P < 0.05). The embedding rate of curcumin in prepared LG-DCQAs complexes using ultrasound could reach 49 % - 62 %, proving that complexes could embed curcumin effectively. This study highlights the benefit of ultrasound application in fabrication of protein-polyphenol complexes for delivering curcumin.

Reductive dechlorination of 2,4-dichlorophenol by using MWCNTs-Pd/Fe nanocomposites prepared in the presence of ultrasonic irradiation

The research on developing a purification technology for 2,4-dichlorophenol (2,4-DCP) polluted water with high efficiency and the low energy consumption is crucial for achieving several Sustainable Development Goals (SDGs). In order to achieve these goals, MWCNTs-Pd/Fe nanocomposites were prepared by Fe nanoparticles modified with multi-walled carbon nanotubes (MWCNTs) and palladium (Pd) in the presence of ultrasonic irradiation. The MWCNTs-Pd/Fe nanocomposites were characterized by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-Ray Diffraction (XRD), and others. Characterization results confirmed that the MWCNTs-Pd/Fe was successfully prepared, with the particle size of 80 nm and the specific surface area of 89.5 m2/g confirmed. We studied the reductive dechlorination of 2,4-Dichlorophenol (2,4-DCP) by MWCNTs-Pd/Fe nanocomposites under different conditions, and the optimized experimental results were found when the Pd loading was 0.4 %, the pH was 3, and the temperature was 30 °C. The phenol yield increased from 76.5 % (without ultrasonic irradiation) to 92.3 % (with ultrasonic irradiation) in 300 min and the 2,4-DCP removal rate reached 98.7 % under the optimal conditions. Therefore, ultrasonic irradiation enhanced the performance of MWCNTs-Pd/Fe nanocomposites for 2,4-DCP removal. We also established the degradation mechanism of chlorophenol by analyzing the intermediates, and proposed the degradation kinetics model. The degradation of 2,4-DCP followed the pseudo-first-order kinetics with the rate constant of 0.05988 min-1. Also, this study demonstrated the potential of using ultrasonic irradiation to improve the properties and recovery of MWCNTs-Pd/Fe nanocomposites, contributing to achievement of the Sustainable Development Goals (SDGs), including SDG-3, SDG-6.

In Vitro Gastrointestinal Digestion of Various Sweet Potato Leaves: Polyphenol Profiles, Bioaccessibility and Bioavailability Elucidation

The chemical composition discrepancies of five sweet potato leaves (SPLs) and their phenolic profile variations during in vitro digestion were investigated. The results indicated that Ecaishu No. 10 (EC10) provided better retention capacity for phenolic compounds after drying. Furthermore, polyphenols were progressively released from the matrix as the digestion process proceeded. The highest bioaccessibility of polyphenols was found in EC10 intestinal chyme at 48.47%. For its phenolic profile, 3-, 4-, and 5-monosubstituted caffeoyl quinic acids were 9.75%, 57.39%, and 79.37%, respectively, while 3,4-, 3,5-, and 4,5-disubstituted caffeoyl quinic acids were 6.55, 0.27 and 13.18%, respectively. In contrast, the 3,4-, 3,5-, 4,5-disubstituted caffeoylquinic acid in the intestinal fluid after dialysis bag treatment was 62.12%, 79.12%, and 62.98%, respectively, which resulted in relatively enhanced bioactivities (DPPH, 10.51 μmol Trolox/g; FRAP, 8.89 μmol Trolox/g; ORAC, 7.32 μmol Trolox/g; IC50 for α-amylase, 19.36 mg/g; IC50 for α-glucosidase, 25.21 mg/g). In summary, desirable phenolic acid release characteristics and bioactivity of EC10 were observed in this study, indicating that it has potential as a functional food ingredient, which is conducive to the exploitation of the sweet potato processing industry from a long-term perspective.

Content of Bioactive Compounds in Highbush Blueberry Vaccinium corymbosum L. Leaves as a Potential Raw Material for Food Technology or Pharmaceutical Industry

This study was performed to investigate the content of selected phenolic compounds, antioxidant activity and the levels of arbutin and hydroquinone in 25 varieties of highbush blueberry (Vaccinium corymbosum) leaf samples. An analysis of the bioactive components was performed using the HPLC technique and the antioxidant activity was determined via spectrophotometric methods. The content of chlorogenic acid in the analysed leaf extracts ranged from 52.76 mg/g (Spartan variety) to 32.37 mg/g (Nelson variety) and was present in the highest concentration among all the analysed phenolic acids. Particularly large levels of isoquercetin were found in the Aurora, Ivanhoe and Toro varieties (28.40 mg/g, 26.24 mg/g and 21.57 mg/g, respectively). An exceptionally high rutin content (p < 0.05) was found in the Ivanhoe variety (27.19 mg/g) as compared to the other varieties, where it ranged from 2.06 mg/g (Earliblue and Patriot varieties) to 10.55 mg/g (Bluejay variety). The Patriot variety was determined to possess the highest antioxidative activity using the FRAP method (1086.15 μmol Trolox/g d.w.) and based on its DPPH radical scavenging activity (1124.17 μmol Trolox/g d.w.). The total phenolic content (TPC) determined via spectrophotometry ranged from 48.11 mg GAE/g d.w. (Elizabeth variety) to 177.31 GAE/g d.w. (Patriot variety). The arbutin content in the leaves of all tested varieties exceeded 2%, so it can be concluded that they constitute a stable source of arbutin. Three varieties (Bonus, Chanticleer and Herbert) can be considered a potential alternative to bearberry and lingonberry leaves. The hydroquinone content in the analysed extracts was determined to be at a lower level. V. corymbosum leaves can be considered an interesting herbal material for use in traditional herbal medicinal products but not directly for food products and dietary supplements.

Analysis of non-covalent interaction between β-lactoglobulin and hyaluronic acid under ultrasound-assisted treatment: Conformational structures and interfacial properties

Hyaluronic acid (HA) used as a food ingredient is gaining acceptance and popularity. However, the studies available for the effect of HA concentrations on the properties of β-lactoglobulin (β-LG) were limited. In this study, we investigated that the molecular characterization and functional properties of the complex formed by the non-covalent binding of β-LG and HA, as well as the ultrasound-assisted treatment at acidic pH. The optimal pH and ratio of β-LG/HA were set as 7 and 4:1, respectively. The fluorescence spectroscopy, circular dichroism spectroscopy, and molecular docking results revealed that the addition of HA and ultrasound induced a decrease in random coil and α-helix and an increase in β-sheet contents in β-LG. By the complexation with HA, the thermal stability, freezing stability, and antioxidant properties of β-LG were all improved under ultrasound treatment. The results of the present study can be useful for the modulation of HA based biopolymer complexes and the exploitation as encapsulating or structuring agents in food industry.