查找使用阿拉丁产品的科研文献

Elucidating key aroma compounds of braised squab and providing insights into their potential precursor

Jinhao Zou,Xuping Wang,Jingrong Cheng,Xueming Liu,Yantian Tang,Anping Li,Daobang Tang

20 shared key aroma compounds were identified from braised squab from different sources. • The influence of key aroma compounds on the overall aroma profile of braised squab was clarified. • The unique contributions of key aroma compounds to different aroma attributes were revealed through the PLSR model. • The sources of key aroma compounds were clarified and their potential precursors were analyzed through the recipe omission models. The key aroma compounds of braised squab from different sources and their potential precursor sources were investigated by molecular sensory science approaches. A total of 58 volatile compounds were identified from different samples, including 20 shared key aroma compounds, which contribute differently to aroma attributes and overall aroma. Partial least squares regression and aroma source analysis indicated that the key aroma compounds contributing significantly to meaty (methional, 1-octen-3-ol) and fatty notes (hexanal, benzeneacetaldehyde, 2-pentyl-furan) mainly originate from raw squab. Condiments and the crisping agent provided precursor sources for roasty (2,5-dimethyl-pyrazine, 3-ethyl-2,5-dimethyl-pyrazine) and caramel-sweet (furfural, maltol) notes. Spices provided a variety of key aroma compounds with plant aroma, and they significantly contributed to spiced-braised notes (terpinen-4-ol, o-cymene, d -limonene, eucalyptol, and anethole) of braised squab. Substantially, the condiments, spices, crisping agent, and raw squab together created the characteristic aroma of braised squab under the various chemical reactions.

Nitrogen Migration and Conversion in Chars from Co-Pyrolysis of Lignocellulose Derived Pyrolysis Model Compounds and Urea-Formaldehyde Resin Adhesive

Mengyao Guo,Shu Yu,Shu Zhang,Juntao Wei,Wenran Gao,Weina Bao,Lei Shi,Hong Zhang,Deliang Xu

In thermal conversion utilization, nitrogen-rich biomass such as waste wood-based panels will release a large amount of NOxinto the atmosphere, causing serious harm to the surroundings. By means of co-pyrolysis, N in waste wood-based panels can be fixed in chars instead of discharging into the atmosphere in the form of volatile matter, which can reduce NOxemission and lay a foundation for the preparation of nitrogen-rich carbon materials with high added value. As the most commonly used adhesive in the production of wood-based panels, urea-formaldehyde resin adhesive (UF) is the main nitrogen source in waste wood-based panels. Therefore, the purpose of this paper is to explore the effects of glucose, ethyl maltol and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) on nitrogen migration and conversion during UF pyrolysis by adjusting the different proportions of model compounds and UF. Thermogravimetric analysis showed that ethyl maltol and DMHF had lower thermal stability and the pyrolysis process was concentrated in the range of 90–168 °C, which does not coincide with the mass loss temperature of UF. UF can promote the pyrolysis of these three model compounds at the initial stage to some extent. The elemental analysis showed that the N retention in co-pyrolysis chars increased in varying degrees with the increase of the addition of model compounds; the nitrogen retention in chars of glucose-UF, ethyl maltol-UF and DMHF-UF increased by 28.47%, 3.48% and 16.45% with the increase of the model compound content from 50% to 90%, respectively. The XPS results showed that the relative content of N-6 in chars increased with the increase of ethyl maltol content, and the relative content of N-5 in chars increased with the increased addition of DMHF. Glucose had little effect on the distribution of N-functional groups in chars.Keywords:wood;thermal conversion;model compounds;urea-formaldehyde resin adhesive;char;nitrogen migration and transformation

Kapok fiber-supported liquid extraction for convenient oil samples preparations: A feasibility and proof-of-concept study

Di Chen,Bin Wang,Xin-Li Xu,Man-Yu Zhang,Xin-Miao Bu,Sen Yang,Yanbo Luo,Xia Xu

In this study, a novel kapok fiber-supported liquid extraction (KF-SLE) method was developed for conveniently extracting analytes from oil samples. Natural kapok fiber without any pretreatment was directly used as an oil support medium. The extraction device was conveniently constructed by directly packing some kapok fibers into a syringe tube. Due to the fibrous property of the kapok fiber, no filter plate was needed. The cost of a KF-SLE device was as low as 0.5 CNY. The KF-SLE process was conveniently conducted using a simple three-step protocol: (1) the oil sample without any pretreatment including dilution was added directedly; (2) then, the oil-immiscible extractant was added; (3) after waiting a certain time for static extraction, the extractant was eluted out by pressing the kapok fibers with the syringe plunger. The extractant could be directly transferred for subsequent instrumental detection. For the feasibility and proof-of-concept study, the method was applied to quantify four synthetic flavor chemicals in edible oils. Satisfied quantification results were obtained with the correlation coefficient (R 2 ) being greater than 0.996, the relative recoveries ranging from 92.90% to 107.53% and intra- and inter-day RSDs being less than 7.56%. All in all, for the first time, the SLE technique was expanded to process oil samples and the method has the characteristics of low cost, environmental friendliness, high sample processing throughput and ease of automation, offering a promising approach for edible oil sample preparations.

Simultaneous determination of multiple flavorings in infant formula by direct analysis in real time-mass spectrometry

Li Minglei,Wang Dingzhong,Zhao Wuduo,Xi Hui,Xu Hengyi,Sun Shihao,Fu Yingjie,Zhang Shusheng,Mao Jian,Zhang Jianxun

The excessive flavorings in food are a growing public health concern, particularly in foods for infants and children. A rapid and simple method for simultaneous detection of multiple flavorings in food is urgently needed. In this work, a method with direct analysis in real time-mass spectrometry has been developed and applied to the simultaneous determination of four flavorings, including maltol, ethyl maltol, vanillin, and ethyl vanillin. The ionization efficiency of flavor compounds in the quantitatively-dip-it probe mode was compared with that in the quick strip mode, which revealed that a solvent-assisted ionization mechanism might be involved in the ionization process. The developed method showed good linearity ( R 2  > 0.99) in the range from 5 to 1000 μg L −1 , sensitivity (LODs <3.3 μg L −1 ), recoveries (84.8%–96.9%), satisfactory repeatability (RSD <14.3%, n = 5), and high-throughout (12 infant formula samples completed in 15 min). The LOQs (0.55–1.1 mg kg −1 ) for the infant formula sample were much lower than the regulatory limits. The developed method provided an alternative way to monitor the excessive addition of flavorings.

Integrated Fe(III)-driven liquid-phase microextraction–spectrophotometry for selective and high-throughput detection of ethyl maltol in complex food samples

Qi Junfeng,Liu Junhe,Hu Chanjuan,Wang Qingqing,Guo Yanhong,Zhang Mengdie,Hu Li,Lin Bin,Li Wansen

Excessive addition of ethyl maltol (EMA) to foods poses potential health risks, highlighting the need for reliable monitoring. Herein, an integrated Fe(III)-driven liquid-phase microextraction (LPME)–spectrophotometry system was developed for selective and high-throughput EMA determination. Fe(III) in the acceptor phase served dual roles: as a chemical trap achieving >90% extraction efficiency and as an in situ chromogenic probe enabling direct detection. This unique design combines membrane-mediated matrix exclusion with coordination-assisted extraction, resulting in enhanced sensitivity and improved resistance to matrix interference. Density functional theory calculations revealed that Fe(III) facilitated the forward extraction by reducing the transmembrane transfer free energy barrier while suppressing back-extraction via weakening EMA–membrane solvent interactions. Under the evaluated conditions, the system offered a broad linear range (7.8–1500 μM, R 2  > 0.999), low detection limit (0.67 μM), and satisfactory selectivity toward structural analogues. Validation in diverse food matrices yielded recoveries of 88–107% with good agreement with HPLC–UV ( R 2  > 0.99). The minimal solvent consumption, high throughput, and favorable greenness further highlight its practical utility. More than an EMA detection method, this work provides a proof-of-concept for the coordination-driven LPME strategy that intrinsically integrates sample preparation with in situ signal generation, offering new insights into the design of a mechanism-driven microextraction system. Graphical abstract

A lateral flow immunoassay method for the rapid detection of acetochlor and alachlor in vegetable oil by sensitivity enhancement by using dimethyl-β-cyclodextrin

Zepeng Li,Yuxiang Wu,Zijing Li,Binger Yu,Xinyi Mao,Guoqing Shi

Acetochlor is an endocrine disruptor. The acetochlor residue is strongly lipophilic and can be enriched into products during the manufacturing process. In this study, we found that dimethyl-β-cyclodextrin (DM-β-CD) solution could decrease the apparent oil/water partition coefficient (Koil–w) of acetochlor and increase the sensitivity of fluorescence lateral flow immunoassay (LFIA) for acetochlor simultaneously. Based on this, a simple LFIA method for the determination of acetochlor and alachlor residues in vegetable oil was established. The detection process only involves vortex mixing of an oil sample and dimethyl-β-cyclodextrin solution in a 1 : 3 (V/V) ratio, loading the water phase onto the immunoassay strips and reading the results. Under optimized conditions, the LOD for acetochlor in oil was 3.53 ng g−1, and the working range was 12.03–2000.00 ng g−1. The recoveries of spiked samples ranged from 91.69% ± 1.12% to 112.23% ± 2.20%. Meanwhile, the cross reactivity for alachlor was 108.22%, while for other investigated acetochlor analogues it was less than 1%, and the recoveries of alachlor were from 92.90% ± 8.03% to 113.53% ± 3.40%, which indicate that this method can detect acetochlor and alachlor simultaneously. Compared with the traditional detection method, the pre-treatment process of the proposed method is “green” and simple, and can be applied to the on-site rapid detection of acetochlor and alachlor in vegetable oil and can provide inspiration for the detection of other lipophilic pollutants.

Superparamagnetic core-shell dummy template molecularly imprinted polymer for magnetic solid-phase extraction of food additives prior to the determination by HPLC

Xin Fu,Dongliang Zhu,Lan Huang,Xiangyang Yan,Shaomin Liu,Chenghui Wang

A highly sensitive and selective method for the simultaneous extraction and determination of trace vanillin , ethyl vanillin , maltol and ethyl maltol in beverage samples using magnetic solid-phase extraction coupled with high-performance liquid chromatography (HPLC) was developed. The novel superparamagnetic dummy template molecularly imprinted polymers (Fe 3 O 4 @MDMIP) were prepared by adopting a sol-gel approach using 3-hydroxy-2,6-bis(hydroxymethyl) -4-pyrone, whose structure was similar to that of the vanillin and maltol, as the dummy template for selective extraction of vanillin, ethyl vanillin, maltol and ethyl maltol. The obtained Fe 3 O 4 @MDMIP exhibits high uniformity and monodispersity. Besides, Fe 3 O 4 @MDMIP has an outstanding magnetic susceptibility (56.33 emu g −1 ) than common obtained samples. The maximal adsorption capacity (Q max ) of the resulting Fe 3 O 4 @MDMIP for the four food additives was up to 609.99 mg g −1 . The imprinting factors of the Fe 3 O 4 @MDMIP ranged from 2.07 to 2.71 for the four food additives, which indicated that the obtained adsorbents have high selectivity. Under the optimum experimental conditions, the Fe 3 O 4 @MDMIP was successfully applied to the magnetic solid-phase extraction of vanillin, ethyl vanillin, maltol and ethyl maltol followed by HPLC determination in beverage samples. Validation experiments indicated that the developed method presented good linearity (2.07–463 ng mL −1 ), satisfactory precision (RSD, 2.68–6.91%), and high recovery (91.2–107.1%). The limits of detection ranged from 44 to 201 ng L −1 , and the enrichment factors were in the range of 432–484. The results demonstrated great potential of the optimized method for sample preparation in routine analysis of trace food additives.

Rapid Determination of Flavorings in e-Cigarette Liquid by Direct Analysis in Real Time (DART) Mass Spectrometry (MS) in the Quick Strip Mode

Xuerui Lou,Minglei Li,Weiwei Guo,Yingjie Fu,Hui Xi,Peng Li,Wuduo Zhao,Shihao Sun

Electronic cigarettes (E-cigarettes) have become popular around the world. An important reason is the variety of available flavors. However, many countries have imposed restrictions on flavor substances in E-cigarettes due to their potential health risks. Therefore, it is necessary to develop an effective way to identify flavorings in E-cigarette liquids. In this work, direct analysis in real time-mass spectrometry (DART-MS) in the quick strip (QS) mode was developed and applied to determine flavorings in the E-cigarettes. Vanillin, ethyl vanillin, maltol, and ethyl maltol were quantified. Meanwhile, the ionization efficiency of flavorings in the different solvents was compared in the QS mode, which revealed that the solvent boiling point was related to the analyte ionization efficiency. The effect of endogenous matrix (propylene glycol and glycerol) on flavoring ionization was also investigated. Calibration curves with satisfactory linearity (R2 > 0.99) were established from 1 to 1000 μg L−1. Good sensitivity (limits of detection [LODs] < 0.3 μg L−1), recoveries (92.6% to 104.7%), and acceptable repeatability (relative standard deviations < 14.6%, n = 5) were obtained. The limits of quantification (LOQs; 10–50 μg g−1) for the E-cigarette liquid sample were much lower than the regulatory limits. The developed method provided a simple way for rapidly determining flavorings in E-cigarettes.

Revealing the impact of processing technology on the aroma profile of Roasted coffee (Coffea Arabica) oil using Flavoromics strategy and chemometrics

Yanru Qiu,Yudong Wang,Wenrou Su,Feifei Wang