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1.
Materials (Basel) ; 16(6)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36984249

RESUMO

Lead-free barium calcium titanate zirconate (BCTZ) ceramics doped with a single rare-earth element generally exhibit excellent piezoelectric properties. However, their electrical properties deteriorate at an excessive dopant content, limiting their application. In this study, amphoteric neodymium (Nd3+) and yttrium (Y3+)-codoped BCTZ-NYx ceramics were synthesized via a solid-state reaction at 1240 °C. The influences of the Y3+ content (x) on the structural features, electrical properties, mechanical properties, and thermophysical properties were investigated. At a small x (<0.18 mol%), Y3+ could enhance the fracture strength and electrical properties by eliminating oxygen vacancies, defect dipoles, and/or structural defects. However, the outstanding performance deteriorated with excessive x. Additionally, the mechanism of the defect chemistry at different x was deduced. At an yttrium content of 0.18 mol%, the ceramic exhibited high piezoelectricity and ferroelectricity with low domain-switching activation energy (Ea = 0.401 eV), indicating that it could replace commercial lead-based piezoelectric ceramics.

2.
Front Plant Sci ; 13: 873065, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35548279

RESUMO

This paper reports on the measurement of optical property mapping of apples at the wavelengths of 460, 527, 630, and 710 nm using spatial-frequency domain imaging (SFDI) technique, for assessing the soluble solid content (SSC), firmness, and color parameters. A laboratory-based multispectral SFDI system was developed for acquiring SFDI of 140 "Golden Delicious" apples, from which absorption coefficient (µ a ) and reduced scattering coefficient (µ s ') mappings were quantitatively determined using the three-phase demodulation coupled with curve-fitting method. There was no noticeable spatial variation in the optical property mapping based on the resulting effect of different sizes of the region of interest (ROI) on the average optical properties. Support vector machine (SVM), multiple linear regression (MLR), and partial least square (PLS) models were developed based on µ a , µ s ' and their combinations (µ a × µ s ' and µ eff ) for predicting apple qualities, among which SVM outperformed the best. Better prediction results for quality parameters based on the µ a were observed than those based on the µ s ', and the combinations further improved the prediction performance, compared to the individual µ a or µ s '. The best prediction models for SSC and firmness parameters [slope, flesh firmness (FF), and maximum force (Max.F)] were achieved based on the µ a × µ s ', whereas those for color parameters of b* and C* were based on the µ eff , with the correlation coefficients of prediction as 0.66, 0.68, 0.73, 0.79, 0.86, and 0.86, respectively.

3.
Food Chem ; 374: 131610, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-34823938

RESUMO

In this work, a robust method for the separation of gardenia yellow and geniposide from gardenia fruit was developed based on a molecularly imprinted solid phase extraction (MISPE) procedure. First, hydrophilic molecularly imprinted microspheres (HMIMs) were prepared using gardenia yellow as the template via reversible addition fragmentation chain transfer (RAFT) precipitation polymerization. The resultant HMIMs demonstrated the multiresponsiveness to pH, temperature, and magnetism, achieving controllable uptake and release of gardenia yellow and easy recovery by external magnets. Meanwhile, the HMIMs possessed high adsorption capacity, fast binding kinetics, specific recognition, and reusability. Finally, a MISPE approach using HMIMs as adsorbent was developed for extraction of gardenia yellow and purification of geniposide after optimization of the adsorption and elution conditions. Thus, efficient separation of gardenia yellow and geniposide with relative purities of 99.77 ± 0.05% (94.04 ± 0.10% recovered) and 94.50 ± 0.62% (95.40 ± 0.86% recovered), respectively, was achieved.


Assuntos
Gardenia , Frutas , Iridoides , Microesferas , Extratos Vegetais
4.
Food Chem ; 372: 131269, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34655829

RESUMO

Lutein is a carotenoid with several beneficial functions, but its poor water solubility, chemical instability, and low bioavailability limits its application. To overcome these shortcomings, self-assembly composite nanoparticles from Stauntonia brachyanthera seed albumin (SBSA), gum Arabic (GA), and carboxymethylcellulose (CMC) were developed for lutein encapsulation. Firstly, SBSA was extracted from seeds and its physicochemical properties were evaluated. Followingly, the nanoparticles were prepared with SBSA through a heat induced self-assembly method which were modified by GA and CMC. The nanoparticles exhibited good storage, pH, and salt stability. Hydrogen bonds, hydrophobic interactions, and electrostatic interactions were proved to derive the formation of nanoparticles. The maximum effective loading capacity (LC) of the lutein in nanoparticles was 0.92 ± 0.01% with an encapsulation efficiency (EE) at 83.95 ± 0.98%. Heat stability and storage stability of lutein were significantly enhanced after encapsulation into nanoparticles. In addition, the bioaccessibility of lutein increased from 17.50 ± 2.60% to 46.80 ± 4.70% after encapsulation into nanoparticles.


Assuntos
Goma Arábica , Nanopartículas , Albuminas , Carboximetilcelulose Sódica , Luteína , Tamanho da Partícula
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