Unveiling microwave and Roasting-Steam heating mechanisms in regulating fat changes in pork using cell membrane simulation.

Fat reduction due to heating or cooking is an important issue in a healthy diet. In the current study, pork subcutaneous back fat was treated via microwave heating (MH) within 10-90 s and roasting - steam heating (RSH) within 2-30 min and their dynamic changes of individual adipocytes were explored by using vesicles as a bio-membrane model. The result showed that MH and RSH significantly increased fat loss (P < 0.05), with the maximum losses being 74.1 % and 65.6 %, respectively. The mechanical strength of connective tissue decreased and then increased slightly. The microstructure demonstrated that MH and RSH treatments facilitated a large outflow of fat, showing that the particle size of the vesicle and individual adipocytes increased and then decreased. It is thus feasible to study the dynamic changes of individual adipocytes in regulating fat reduction using cell membrane simulation.

Nano-encapsulation of polyphenols in starch nanoparticles: fabrication, characterization and evaluation.

Nanoparticles are more promising than microcapsules as drug carriers because they can be absorbed directly by intestinal epithelial cells, significantly increasing the uptake and bioaccessibility of polyphenols. Our study aimed to use catechin (CC), epicatechin (EC) and proanthocyanidin (PAC) adsorption onto tapioca starch nanoparticles (TSNs), which were prepared by a physical method. These TSN loaded-polyphenols were subjected to adsorption kinetic, adsorption isotherm, adsorption capacity, antioxidant activity, and in vitro release analyses. The maximum adsorption capacities of TSNs for CC, EC and PACs were 179.39 mg g-1, 109.29 mg g-1 and 287.19 mg g-1, respectively. The adsorption dynamics and isotherms of polyphenols on TSNs conformed well to the pseudo-second-order kinetics and the Freundlich isotherms. Moreover, TSN loaded-polyphenols have low cytotoxicity and can continuously be released under stimulated gastric and intestinal conditions. Antioxidant activity tests showed that TSN loaded-polyphenols can remarkably scavenge DPPH free radicals; the IC50 of TSNs-CC, TSNs-EC and TSNs-PAC were 16.11, 16.59 and 16.93 µg mL-1, respectively.

Comparison of phytochemical profiles, antioxidant and antiproliferative activities in Chinese bayberry (Myrica rubra Sieb. et Zucc.) fruits.

Here, we examined the phytochemical profiles, antioxidant activity (AA), and antiproliferative activity (APA) of four Chinese bayberry (Myrica rubra Sieb. et Zucc.) pulp extracts. They were found to be rich in total phenolics content (TPC; 186.45 ± 5.42 to 498.94 ± 8.25 mg of gallic acid equiv./100 g FW) and total flavonoids content (TFC; 126.28 ± 4.18 to 194.35 ± 12.03 mg of catechin equiv./100 g FW). For all varieties, the free flavonoid/phenolic/anthocyanin contents were higher than that the bound fractions. Wild pink bayberry (WPB) displayed the highest values of TPC and TFC, and also showed the highest total antioxidant activity (TAA) as revealed by peroxyl radical scavenging capacity (PSC) (451.47 ± 8.01 µmol Vit. C equiv./100 g FW), and free cellular antioxidant activity (CAA) (184.99 ± 6.11 µmol quercetin equiv./100 g FW, no PBS wash; 117.78 ± 2.34 µmol quercetin equiv./100 g FW, PBS wash) assays. Bayberry extracts had a marked reduction in the APA of HepG2 cells, and WPB exhibited the lowest EC50 (8.50 ± 0.83 mg/ml) value, which was probably associated with cell cycle arrest and apoptosis induction. PRACTICAL APPLICATION: Chinese bayberry (Myrica rubra Sieb. et Zucc.) fruit is rich in natural phenolic compounds, which might be a functional ingredient in food and nutraceutical products. Our findings would provide a logical strategy to promote the comprehensive utilization of phenolics in bayberry fruit with both health and economy benefits.

Wild pink bayberry fruit: the effect of in vitro gastrointestinal digestion on phytochemical profiles, and antioxidant and antiproliferative activities.

The regular consumption of polyphenol-rich foods is essential to prevent the onset of diseases. Wild fruits are known to possess higher levels of bioactive components than the domesticated fruits because of the severe environmental conditions they are grown in. The aim of this study was to evaluate the phytochemical profiles, and antioxidant and antiproliferative activities of a wild pink bayberry fruit after in vitro digestion and to compare them with results obtained with a chemical extraction method. A low release of total phenolics and anthocyanins was observed after digestion compared with chemical extraction, while more flavonol contents were found by HPLC analysis. The digesta samples demonstrated low levels of extracellular antioxidant activity (EAA) and cellular antioxidant activity (CAA). However, the cellular uptake rate was increased during the in vitro digestion, and the largest value of 75.35% was obtained in the colon step. Notably, the antiproliferative activity in the colon digesta (10.14 ± 0.13 mg mL-1) was close to that of extracts (7.6 ± 0.63 mg mL-1). Pearson correlation analysis revealed that EAA and CAA were significantly correlated with TPC, while the antiproliferative activity was significantly correlated with the total contents of three flavonol compounds (quercetin, kaempferol, and myricetin). Our observations provide new insights into the bioactivity variation of whole fruits as affected by simulated digestion.

A highly efficient nanoscale tapioca starch prepared by high-speed jet for Cu2+ removal in simulated industrial effluent.

BACKGROUND: Nanoscale tapioca starch (NTS) was successfully developed by high-speed jet in our previous study. In this study, the adsorption capacity of Cu2+ onto NTS was further discussed. The optimal adsorption conditions (pH, contact time, contact temperature, initial Cu2+ concentration, and adsorbent concentration), adsorption kinetics, isotherms, and thermodynamic were also evaluated. RESULTS: The results showed that NTS exhibited excellent performance in adsorption of Cu2+ , with adsorption capacities of 122.31 mg g-1 for Cu2+ (pH 7, 0.04 g L-1 , 0.2 g L-1 , 313.15 K and 10 min). The pseudo-second-order and Langmuir isotherms models could be used to explain the adsorption kinetics and adsorption equilibrium, respectively. The thermodynamic results showed that the adsorption process was spontaneous and endothermic with an increase in entropy. Cu2+ was adsorbed onto NTS, which was confirmed by energy dispersive spectrometry analysis. CONCLUSION: These findings indicated that NTS might be an effective, environment-friendly and renewable bio-resource adsorbent for removing heavy metals in industrial effluent. © 2021 Society of Chemical Industry.

Fabrication, characterization and evaluation of myricetin adsorption onto starch nanoparticles.

Myricetin (MY) is a natural antioxidant flavonoid with a variety of biological activities. However, extremely low water solubility, bioavailability, and easy degradation, restrict their application. Recently, increasing interest in starch nanoparticles as a new kind of biocompatible renewable polymer in applications like nanocarriers. This work was to fabricate MY adsorption onto tapioca starch nanoparticles (TSNPs) and evaluate their biological activities. The adsorption mechanism, loading amount, antioxidative capacity, and in vitro release of the loaded MY were also analyzed. The adsorption kinetics and adsorption equilibrium were best explained by a pseudo-second-order model and Freundlich isotherms, respectively. Based on the thermodynamic parameters, adsorption was found to be a spontaneous and exothermic process with a decrease in entropy. MY possessed a maximum equilibrium adsorption capacity of 453 ± 8.07 mg/g. Low cytotoxicity were obtained as described by methylene blue assay, and a sustained release of loaded MY was observed in stimulated gastric (pH 2.0) and intestinal (pH 7.0) fluids. Additionally, the rate of clearance of DPPH free radicals was increased by the adsorption of MY onto TSNPs, which was confirmed by the lower value of 50 % inhibitory concentration (IC50).

Modified xanthan gum for methyl orange uptake: Kinetic, isotherm, and thermodynamic behaviors.

A novel hydrogel, named XGTTE, was prepared by modification of acrylamide and trimethylolpropane triglycidyl ether (TTE) on xanthan gum (XG). XGTTE was utilized as an adsorbent to remove methyl orange (MO) from an aqueous solution. Functional groups present in the external surface of XGTTE, such as carboxyl, hydroxyl, and amino groups, were identified, and these functional groups are responsible for the occurrence of the mechanism for MO adsorption. The structure of XGTTE after MO adsorption became more disordered. The adsorption dynamics and isotherms of MO onto XGTTE conformed well to the pseudo-second-order kinetics and the Freundlich equation, indicated that the adsorption included physical and chemical adsorption, with electrostatic interaction and hydrogen-bonding interaction. The calculated values of the thermodynamic parameters, such as changes in enthalpy (ΔH) and entropy (ΔS) were 27.30 kJ/mol and 125.63 J/mol/K, respectively. The changes in free energy (ΔG) were - 9.53 kJ/mol (293.15 K), -10.16 kJ/mol (298.15 K), -10.78 kJ/mol (303.15 K), -11.41 kJ/mol (308.15 K), and - 12.04 kJ/mol (313.15 K), respectively, indicating the adsorption process is endothermic, spontaneous, and entropic. The maximum adsorption capacities of XGTTE2, XGTTE3, XGTTE4, XGTTE5, and XGTTE6 for MO were 18.62 ± 0.99, 21.92 ± 0.84, 28.60 ± 0.84, 29.56 ± 0.99, and 12.38 ± 0.84 mg/g, respectively.

Modified xanthan gum for crystal violet uptake: kinetic, isotherm, and thermodynamic behaviors.

Modified xanthan gum (XG-AM-TTE) was employed as an adsorbent to study the adsorption behavior, thermodynamics and kinetics of crystal violet (CV) from an aqueous solution. Fourier transform infrared spectroscopy analysis indicates that the functional groups present in the adsorbent, such as carboxyl, ester and hydroxyl groups, are included on the external surface of the material, and these groups are potential active sites for interaction with CV. According to X-ray diffraction results, the structure of XG-AM-TTE after CV adsorption became more disordered, and the microstructure change is an indication of effective adsorption of CV to the surface, with CV becoming remarkably dispersed in the adsorbent according to the scanning electron microscopy observations. The adsorption kinetics and adsorption equilibrium were best described by the pseudo-second-order model and Freundlich isotherms, respectively. The thermodynamic parameters, as the Gibbs-free energy (ΔG), enthalpy (ΔH) and entropy (ΔS), indicated that the adsorption is a spontaneous, endothermic and entropy increase process. The maximum adsorption capacity of XG-AM-TTE was 183 ± 12 mg/g, suggesting that XG-AM-TTE is an efficient adsorbent.

pH-responsive poly (xanthan gum-g-acrylamide-g-acrylic acid) hydrogel: Preparation, characterization, and application.

Poly (xanthan gum-g-acrylamide-g-acrylic acid) (XGDA) hydrogel was prepared by grafting acrylamide (AM) and partly neutralized acrylic acid (AA) onto xanthan gum (XG) with trimethylolpropane triglycidyl ether as a cross-linking agent. With the introduction of amino and carboxyl groups by AM and AA, the XG molecules were rearranged with better regularity, leading to higher thermal stability and a more porous structure. The resulting hydrogel exhibited excellent performance in Cu (II)-adsorption and possessed sensitivity to external pH stimuli. The adsorption kinetics and adsorption equilibrium were best described by a pseudo-second-order model and Freundlich isotherms, respectively. The thermodynamic parameters indicated that the adsorption is a spontaneous, endothermic, and a process that increases entropy. The maximum equilibrium adsorption capacity of Cu (II) was 130.31 ± 2.97 mg/g. The XGDA can be regenerated and reused in the following adsorption process. This pH-sensitive hydrogel has potential to be used for the uptake of heavy metal ions from aqueous solution.

The synthesis and characterization of a xanthan gum-acrylamide-trimethylolpropane triglycidyl ether hydrogel.

To improve the thermal stability and adsorption performance, xanthan gum was modified with acrylamide and trimethylolpropane triglycidyl ether (TTE). The modified xanthan gum (XGTTE) was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffractogram (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The characteristic peaks at 3449, 1655, 1611 and 1420 cm-1 in the FT-IR confirm the modification. The XGTTE crystal grew well upon addition of TTE. The XRD and DSC data revealed that the XGTTE enhanced its thermal stability. Analysis of SEM revealed that the grafting introduced major changes on the microstructure making it porous and resulting in the adsorption of crystal violet (CV) with flocculation. The CV adsorption capacity of the hydrogel with different dosages of TTE (XGTTE2, XGTTE3, XGTTE4, XGTTE5 and XGTTE6) were between 28.13 with 35.12 mg/g. In addition, the adsorption capacity, thermal stability, and swelling property of XGTTE4 were the best.

A novel sound-blocking structure based on the muffler principle for rib-sparing transcostal high-intensity focused ultrasound treatment.

The main challenge in transcostal high-intensity focused ultrasound therapy is minimising heat deposition in the ribs while ensuring that a sufficient dose is delivered to the target region. Current approaches rely on expensive multichannel phased-array systems to turn the individual transducer on and off according to either geometrical arrangements or complicated wave calculations. To protect the ribs from heating, the ultrasound energy must not only not reach the ribs, but must also not accumulate in front of the ribs. The research in this paper proposes a different approach, of attaching a sound-blocking structure in front of the rib cage with similar effects to those of an engine exhaust muffler. The sound-blocking structure is based on the muffler principle to prevent ultrasound energy from reaching the ribs and reduce the amount of energy reflected back to the applicator. Finite element simulations with a 0.5-MHz transducer of the overall sound fields and temperature distribution showed that the ultrasound pressure and energy level would decrease behind the novel sound-blocking structures, thereby resulting in a lower temperature at the ribs than at the tumour. Without the protecting structure, the rib temperature reached 104.19 °C whereas with the structure it reached only 37.86 °C. An experimental set-up using porcine ribs with a phantom was also developed to validate the concept, which showed that the rib temperature reached 73 °C without protection within 1 min of ablation time whereas it reached 36.5 °C with the device. The tumour region in the tests reached 51 °C and 49 °C with and without protection, respectively.

Effectiveness of external respiratory surrogates for in vivo liver motion estimation.

PURPOSE: Due to low frame rate of MRI and high radiation damage from fluoroscopy and CT, liver motion estimation using external respiratory surrogate signals seems to be a better approach to track liver motion in real-time for liver tumor treatments in radiotherapy and thermotherapy. This work proposes a liver motion estimation method based on external respiratory surrogate signals. Animal experiments are also conducted to investigate related issues, such as the sensor arrangement, multisensor fusion, and the effective time period. METHODS: Liver motion and abdominal motion are both induced by respiration and are proved to be highly correlated. Contrary to the difficult direct measurement of the liver motion, the abdominal motion can be easily accessed. Based on this idea, our study is split into the model-fitting stage and the motion estimation stage. In the first stage, the correlation between the surrogates and the liver motion is studied and established via linear regression method. In the second stage, the liver motion is estimated by the surrogate signals with the correlation model. Animal experiments on cases of single surrogate signal, multisurrogate signals, and long-term surrogate signals are conducted and discussed to verify the practical use of this approach. RESULTS: The results show that the best single sensor location is at the middle of the upper abdomen, while multisurrogate models are generally better than the single ones. The estimation error is reduced from 0.6 mm for the single surrogate models to 0.4 mm for the multisurrogate models. The long-term validity of the estimation models is quite satisfactory within the period of 10 min with the estimation error less than 1.4 mm. CONCLUSIONS: External respiratory surrogate signals from the abdomen motion produces good performance for liver motion estimation in real-time. Multisurrogate signals enhance estimation accuracy, and the estimation model can maintain its accuracy for at least 10 min. This approach can be used in practical applications such as the liver tumor treatment in radiotherapy and thermotherapy.