Heat-induced conversion of gingerols to shogaols in ginger as affected by heat type (dry or moist heat), sample type (fresh or dried), temperature and time

The impact of heat type, sample type, temperature and time on the heat-induced conversion of gingerols to shogaols in ginger were studied by an UHPLC–ESI–MS/MS. Heat treatments greatly induced the conversion of gingerols to shogaols in ginger. As the temperature increased, the faster conversion of gingerols into shogaols were observed. However, the efficiency of the heat-induced conversion differed greatly with the heat types. Moist heat treatment induced significantly higher quantity of shogaols than dry heat treatment. The moist heat treatment at 120 °C for 360 min induced the highest conversion, reaching to 2991 mg 6-shogaol per kg ginger. In addition, dry-heat induced conversion was affected by the sample type. The dry-heat treatment on dried powder induced significantly higher quantity of shogaols than that on sliced fresh ginger. This represents the first systematic comparative study on the heat and sample types on the heat-induced conversion of gingerols into shogaols in ginger.     

EVALUATION OF SPICES AND OLEORESINS VII. GAS CHROMATOGRAPHIC EXAMINATION OF GINGEROL, SHOGAOL AND RELATED COMPOUNDS IN GINGER

The products of thermal degradation of gingerols, the pungent component of the spice ginger under gas chromatographic conditions have been re-examined. Besides breakdown to zingerone and aldehydes, substantial dehydration of gingerols to shogaols has been established by improved gas chromatographic separation. The identity of the pungent and poorly pungent homologs have been clearly established as (6)- and (8)-, and (10)-gingerols/shogaols respectively. Programmed temperature gas chromatography combined with thin-layer chromatographic separation has provided a method for determining the ratio of the homologs and a possible method for estimation of gingerols and shogaols in ginger oleoresin.     

Simultaneous determination of water-soluble vitamins in beverages and dietary supplements by LC-MS/MS

An LC-MS/MS method was developed for the simultaneous determination of 15 water-soluble vitamins that are widely used as additives in beverages and dietary supplements. This combined method involves the following simple pre-treatment procedures: dietary supplement samples were prepared by centrifugation and filtration after an extraction step, whereas beverage samples were diluted prior to injection. Chromatographic analysis in this method utilised a multi-mode ODS column, which provided reverse-phase, anion- and cation-exchange capacities, and therefore improved the retention of highly polar analytes such as water-soluble vitamins. Additionally, the multi-mode ODS column did not require adding ion pair reagents to the mobile phase. We optimised the chromatographic separation of 15 water-soluble vitamins by adjusting the mobile phase pH and the organic solvent. We also conducted an analysis of a NIST Standard Reference Material (SRM 3280 Multi-vitamin/Multi-element tablets) using this method to verify its accuracy. In addition, the method was applied to identify the vitamins in commercial beverages and dietary supplements. By comparing results with the label values and results obtained by official methods, it was concluded that the method could be used for quality control and to compose nutrition labels for vitamin-enriched products.     

Quantitative Analysis of 10 Mycotoxins in Wheat Flour by Ultrahigh Performance Liquid Chromatography‐Tandem Mass Spectrometry with a Modified QuEChERS Strategy

A simple and sensitive analytical method for quantitative analysis of 10 mycotoxins was developed and validated by a combination of modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure with ultrahigh performance liquid chromatography‐tandem mass spectrometry (UHPLC‐MS/MS). Sample preparation involved QuEChERS with dispersive solid phase extraction for clean‐up, and analysis was performed by reversed‐phase UHPLC‐MS/MS using electrospray negative ionization and multiple reaction monitoring. Under optimized conditions, the calibration curves displayed good linear relationships with all coefficients of determinations (r²) higher than 0.998. The limits of quantification for all target mycotoxins were lower than 7 μg/kg. Trueness and precision for the analytes were 70% to 116% average recoveries and 2% to 13% relative standard deviations (RSDs). The validated method was used to analyze 46 wheat flour samples for the targeted mycotoxins. The method can be used as a rapid and robust tool for screening mycotoxin in cereal products.     

Liquid Chromatography‐Diode Array and Electrospray High‐Accuracy Mass Spectrometry of Iso‐α‐Acids in DCHA‐Iso Standard and Beer

Excellent liquid chromatographic (LC) separation of cis/trans stereoisomers of iso‐α‐acids has been achieved with reversed‐phase sorbent XTerra MS C18. An isocratic alkaline mobile phase, consisting of a mixture of 5 mmol l^?1 ammonium acetate (pH 8)‐acetonitrile‐methanol, 62:21:17 (v/v/v), was used. In the DCHA‐Iso international calibration standard trans‐isoposthumulone was identified combining photo diode array (PDA) spectra and electrospray high‐accuracy mass spectrometric (MS) data. Moreover, the molecular mass of two degradation products resulting from the in‐solution storage of the DCHA‐Iso standard was determined. The presence of trans and cis isomers of isoposthumulone, isocohumulone, isoadhumulone and iso‐n‐humulone in beer samples was confirmed. The trans isomers of iso‐α‐acids showed characteristic and reproducibly slightly different ultraviolet absorbance spectra with respect to cis isomers.     

Optimized Heat Treatment Enhances the Anti-Inflammatory Capacity of Ginger

This study aims to investigate the relationship between constituent contents and anti-inflammatory activities of heat processed gingers, and to optimize heat process to enhance ginger’s anti-inflammatory capacity. After 3 h of heat treatment at 75, 100, and 125°C, the gingerols content was reduced by 6.8, 12.6, and 42.7%, respectively, and the shogaols content was increased by 2.95, 4.85, and 9.34 fold, respectively. After 3 h of heat treatment at 150°C, the gingerols content was dramatically reduced by 89.5% and the increased shogaols content was even lower than treatment at 125°C. The tumor necrosis factor-α-, prostaglandin E2, and nitric oxide-inhibitory capacities of ginger could be increased by heat treatment. However, at high temperature, the enhanced ability would be decreased. The enhanced tumor necrosis factor-α-, prostaglandin E2-, and nitric oxide-inhibitory capacities of ginger was attenuated after 40, 60, and 180 min of heat treatment at 150°C, respectively. The results indicated that the TNF-α-inhibitory capacity of ginger was the most susceptible to heat. Only the prostaglandin E2-inhibitory capacity correlated with the shogaols content, which implies that heat derived shogaols contributed primarily to the prostaglandin E2-inhibitory capacity enhancement. We suggest that the optimal heat process condition is 125°C for 40–60 min for ginger to reach the maximum tumor necrosis factor-α-, prostaglandin E2-, and nitric oxide-inhibitory capacities.     

Simultaneous Determination of 15 Phenolic Constituents of Chinese Black Rice Wine by HPLC‐MS/MS with SPE

This study established a new method for quantitative and qualitative determination of certain components in black rice wine, a traditional Chinese brewed wine. Specifically, we combined solid‐phase extraction and high‐performance liquid chromatography (HPLC) with triple quadrupole mass spectrometry (MS/MS) to determine 8 phenolic acids, 3 flavonols, and 4 anthocyanins in black rice wine. First, we clean samples with OASIS HLB cartridges and optimized extraction parameters. Next, we performed separation on a SHIM‐PACK XR‐ODS column (I.D. 3.0 mm × 75 mm, 2.2 μm particle size) with a gradient elution of 50% aqueous acetonitrile (V/V) and water, both containing 0.2% formic acid. We used multiple‐reaction monitoring scanning for quantification, with switching electrospray ion source polarity between positive and negative modes in a single chromatographic run. We detected 15 phenolic compounds properly within 38 min under optimized conditions. Limits of detection ranged from 0.008 to 0.030 mg/L, and average recoveries ranged from 60.8 to 103.1% with relative standard deviation ≤8.6%. We validated the method and found it to be sensitive and reliable for quantifying phenolic compounds in rice wine matrices.     

Detection of adulteration of anti-hypertension dietary supplements and traditional Chinese medicines with synthetic drugs using LC/MS

A sensitive and specific liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) method was developed for the analysis of 18 drugs used for the treatment of anti-hypertension, including diuretics, calcium antagonists, and angiogenesis-converting enzyme inhibitors (ACEI) as adulterants in dietary supplements and traditional Chinese medicines. Separation was accomplished on a Xtimate? C₁₈ reversed-phase column using a mixture of methanol, acetonitrile and 20 mM ammonium formate buffer (pH 3.2) as mobile phase. The method demonstrated linearity from 0.03 to 21.52 mg kg^?1. Limits of detection ranged from 6.5 to 86.0 µg kg^?1. The recoveries of spiked samples ranged from 71% to 109%. The procedure was successfully applied in routine inspection analysis.     

Steamed ginger (Zingiber officinale): Changed chemical profile and increased anticancer potential

Ginger, from the rhizome of Zingiber officinale Rosco (Zingiberaceae), is a common condiment for foods and beverages. In this work, we tested a hypothesis that a steaming process affects the chemical profile and anticancer potential of ginger. An HPLC method with TOF/MS and DAD was developed to analyse the chemical constituents in ginger. The antiproliferative effect of fresh, dried and steamed gingers was evaluated using human Hela cancer cells. The results showed that the antiproliferative effect of steamed ginger at 120 °C for 4 h was approximately 1.5- and 2-fold higher than that of dried and fresh ginger, respectively. Twenty-two components were characterised in the steamed ginger. The decreased concentration of gingerols and increased levels of shogaols contributed to the improved anticancer potential of the steamed ginger. This study elucidated the relationship of the heating process with the constituents and anticancer activity, and developed an optimised processed ginger extract for chemoprevention.     

EVALUATION OF SPICES AND OLEORESINS — VIII — IMPROVED SEPARATION AND ESTIMATION OF PUNGENT AND RELATED COMPONENTS OF GINGER BY THIN-LAYER CHROMATOGRAPHY

A combination of the wedged-tip TLC technique and choice of solvent polarity has been used to clearly separate the pungent and weakly pungent homologs of gingerols and shogaols of ginger extracts. The quantitative estimation, of the separated components provides valid data for correlation with subjective pungency. By TLC analysis of the alkaline degradation products, the pungent fractions were shown to be the (6) — and the weakly pungent fractions to be (8) — (and possibly (10) —) gingerols and shogaols. Zingerone has not been found even in commercial samples stored over many years.     

Analytical method of cereulide in processed cereal-based foods and milk powder by LC-MS/MS

An LC-MS/MS method for analysis of cereulide, an emetic toxin produced by Bacillus cereus, was developed. Cereulide was extracted from samples, fried rice, pan-fried noodles, red bean paste and baby formula, with methanol and purified using Oasis HLB cartridges. LC separation was performed on a C18 column with a mixture of formic acid solution and methanol containing ammonium formate as a mobile phase, and the mass spectrometer was operated in the positive electrospray ionization mode. Performance evaluation showed that trueness was higher than 70% and repeatability and reproducibility were within 10%. The limits of quantification were lower than 1 μg/kg.     

敞开式离子化质谱新技术及其应用

敞开式离子化质谱(ambient mass spectrometry,AMS)是近年来新兴的一种无需或者只需很少样品前处理步骤,在敞开的大气压环境中可直接对物体表面物质进行离子化的质谱分析技术。本实验室基于敞开式离子源实时直接分析(direct analysis in real time,DART),进行了多方面的研究。主要包括三个方面:第一,应用研究,将简单的样品前处理技术和DART-MS结合,建立了有针对性的快速检测方法;第二,实现正相液相色谱(normal phase liquid chromatography,NPLC)和DART-MS的在线联用,解决了NPLC-MS联用中正相色谱流动相不利于样品离子化的问题,并利用该方法对NPLC分离的手性化合物进行了有效检测;第三,构建了一套新的AMS装置—等离子体辅助多波长激光解吸离子化质谱(plasma assisted multiwavelength laser desorption ioniza-tion mass spectrometry,PAMLDI-MS)。该装置将激光解吸附和等离子体辅助离子化技术相组合,并且将其与简单的TLC快速分离结合,对一些小分子混合物进行了分离检测;实验室还借助简单的铅笔芯中石墨涂覆的滤纸作为PAMLDI-MS的进样基底,发现石墨涂覆的滤纸对于待测样品有很好的基质辅助信号增强作用。     

Rapid Tomato Volatile Profiling by Using Proton‐Transfer Reaction Mass Spectrometry (PTR‐MS)

Abstract: The availability of rapid and accurate methods to assess fruit flavor is of utmost importance to support quality control especially in the breeding phase. Breeders need more information and analytical tools to facilitate selection for complex multigenic traits such as flavor quality. In this study, it is shown that proton‐transfer reaction mass spectrometry (PTR‐MS) is a suitable method to monitor at high sensitivity the emission of volatiles determining the tomato aromatic profile such as hexanal, hexenals, methanol, ethanol, and acetaldehyde. The volatiles emitted by 14 tomato varieties (at red stage) were analyzed by 2 solvent‐free headspace methods: solid‐phase microextraction/gas chromatography MS and PTR‐MS. Multivariate statistics (principal component analysis and cluster analysis) of the PTR‐MS results allow an unambiguous separation between varieties, especially with a clear fingerprinting separation between the different tomato types: round truss, cocktail, and cherry tomatoes. PTR‐MS was also successfully used to monitor the changes in volatile profiles during postharvest ripening and storage. Practical Application: These results show that proton‐transfer reaction mass spectrometry (PTR‐MS) is suited to monitor at high sensitivity the emission of a large number of volatiles that describe the tomato aroma profile. This technology can easily monitor and quantify compounds related to ripening and/or senescence so that it can be used to improve the breeding of new fruit and vegetable cultivars based on volatiles. Moreover, PTR‐MS can be used to monitor changes in volatile profile during ripening and storage.     

Simple and Fast Sample Preparation Followed by Gas Chromatography‐Tandem Mass Spectrometry (GC‐MS/MS) for the Analysis of 2‐ and 4‐Methylimidazole in Cola and Dark Beer

We have developed a simple and fast sample preparation technique in combination with a gas chromatography‐tandem mass spectrometry (GC‐MS/MS) for the quantification of 2‐methylimidazole (2‐MeI) and 4‐methylimidazole (4‐MeI) in colas and dark beers. Conventional sample preparation technique for GC‐MS requires laborious and time‐consuming steps consisting of sample concentration, pH adjustment, ion pair extraction, centrifugation, back‐extraction, centrifugation, derivatization, and extraction. Our sample preparation technique consists of only 2 steps (in situ derivation and extraction) which requires less than 3 min. This method provided high linearity, low limit of detection and limit of quantification, high recovery, and high intra‐ and interday repeatability. It was found that internal standard method with diluted stable isotope (4‐MeI‐d₆) and 2‐ethylimidazole (2‐EI) could not correctly compensate the matrix effects. Thus, standard addition technique was used for the quantification of 2‐ and 4‐MeI. The established method was successfully applied to colas and dark beers for the determination of 2‐MeI and 4‐MeI. The 4‐MeI contents in colas and dark beers ranged from 8 to 319 μg/L and from trace to 417 μg/L, respectively. Small quantity (0 to 8 μg/L) of 2‐MeI was found only in dark beers. The contents of 4‐MeI (22 μg/L) in colas obtained from fast food restaurants were significantly lower than those (177 μg/L) in canned or bottled colas.     

基于UPLC-Triple-TOF MS/MS对巴氏杀菌乳中磷脂成分的分析

基于超高效液相色谱-串联四极杆飞行时间高分辨质谱(ultra-high performance liquid chromatography-triple quadrupole-time of flight tandem mass spectrometry,UPLC-Triple-TOF MS/MS)法对巴氏杀菌乳中的磷...     

Liquid chromatography/mass spectrometry based fingerprinting analysis and mass profiling of Euterpe oleracea (açaí) dietary supplement raw materials

Chemical fingerprinting and mass profiling methods to identify biologically active compounds in botanical dietary supplements is gaining much attention in recent years. Euterpe oleracea (açaí) has been reported to be rich in health-beneficial chemical constituents. We have developed LC/MS based fingerprinting and mass profiling methods to identify fatty acids, anthocyanins and non-anthocyanin polyphenols in three processed raw materials; non-organic açaí powder (ADSR-1), raw-organic açaí powder (ADSR-2) and freeze-dried açaí powder (ADSR-3) that are used in the preparation of botanical dietary supplements. For LC/MS analysis of fatty acids and non-anthocyanin polyphenols, the açaí samples were extracted sequentially with dichloromethane followed by methanol. To study fingerprinting analysis of anthocyanins, açaí samples were extracted with acidic methanol–water. The LC separation of fatty acids, non-anthocyanin polyphenols and anthocyanins in açaí raw materials was achieved using a C18 column with a gradient mobile phase consisting of solvents A (0.1% formic acid in water), and B (0.1% formic acid in methanol). MS experiments were carried out with negative and positive mode electrospray ionization. LC/MS analysis of dichloromethane extracts of (ADSR-1), (ADSR-2) and (ADSR-3) açaí powders have shown to contain fatty acids, γ-linolenic acid, linoleic acid, palmitic acid, and oleic acid. Whereas, the fingerprinting analysis of methanol extracts of ADSR-1, ADSR-2 and ADSR-3 led to the identification of phenolic acids, anthocyanin and non-anthocyanin polyphenols. The results from our study may be useful for the authentication and quality assessment of açaí dietary supplement raw materials.     

Analytical method of hydramethylnon in agricultural products by LC-MS/MS

A simple determination method of hydramethylnon in agricultural products by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The sample was homogenized with phosphoric acid and extracted with acetone. An aliquot of crude extract was re-extracted with hexane and sat. NaCl solution. In the case of tea leaf, solidification processing using ammonium chloride and phosphoric acid was performed before re-extraction with hexane. Clean-up was performed using a silica-gel mini column (500 mg). The LC separation was performed on a C18 column using methanol-water (8 : 2) containing 10 mM ammonium acetate as the mobile phase and MS detection with positive ion electrospray ionization. The calibration curve was linear between 0.002-0.2 μg/mL of hydramethylnon. Recoveries (n=5) of hydromethylnon from 10 kinds of agricultural products fortified at 0.01 μg/g (0.05 μg/g for pineapple) were 82-110%, and their relative standard deviations were 2-12%.     

Identification of the Major Components of Buddleja officinalis Extract and Their Metabolites in Rat Urine by UHPLC‐LTQ‐Orbitrap

Buddleja officinalis Maxim, one of the most popular herbal medicines in China, is widely prescribed for curing eye diseases for centuries. In this study, the major components of B. officinalis extract (BOE) and their metabolites in rat urine were detected and identified by ultra‐high‐pressure liquid chromatography coupled with linear ion trap‐orbitrap tandem mass spectrometry (UHPLC‐LTQ‐Orbitrap). A total of 19 compounds, including 8 flavonoids and 11 phenylethanoid glycosides, were confirmed or tentatively identified from BOE. In vivo, 33 components, including 3 prototypes and 30 metabolies, were confirmed or tentatively identified in rat urine samples. The metabolic pathways of different types of compounds were also proposed. This study would effectively narrow the range of potentially bioactive constituents of BOE and shed light to its action mechanism.     

Analysis of six synthetic adulterants in herbal weight-reducing dietary supplements by LC electrospray ionization-MS

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method was developed for the simultaneous determination of six synthetic adulterants, namely fenfluramine, phenolphthalein, N-di-desmethyl sibutramine, N-mono-desmethyl sibutramine, sibutramine, and orlistat. The method was applied to the analysis of herbal weight-reducing dietary supplements. Chromatographic separation of the analytes on a C(8) reversed-phase column was achieved using a gradient elution of solvent A: acetonitrile and solvent B: aqueous 20 mM ammonium formate solution. Sildenafil was utilized as an internal standard for quantification. The MS detector was operated in positive electrospray ionization mode. Selected-ion monitoring (SIM) was carried out for m/z 232, 319, 252, 266, 280, 496, and 475 for fenfluramine, phenolphthalein, N-di-desmethyl sibutramine, N-mono-desmethyl sibutramine, sibutramine, orlistat, and sildenafil, respectively. The method was validated for accuracy, precision, linearity, and selectivity. The limits of detection for the six synthetic adulterants ranged from 0.0018 to 0.73 microg g(-1). The proposed method was used for a small survey of 22 dietary supplements of which eleven samples were adulterated with phenolphthalein, N-mono-desmethyl sibutramine, and sibutramine at levels from 0.212 to 96.2 mg g(-1).     

Determination of para-synephrine and meta-synephrine positional isomers in bitter orange-containing dietary supplements by LC/UV and LC/MS/MS

Dietary supplements that contain bitter orange (Citrus aurantium) fruit as an integrated component have rapidly replaced ephedra-containing dietary supplements for use as weight loss products. However, the safety of bitter orange-containing supplements has been questioned because synephrine, an adrenergic alkaloid and a key component of bitter orange fruit, has potential adverse health effects. Conflicting reports have stated that synephrine exists as the para (p) and/or meta (m) positional isomers in some bitter orange-containing supplements and this is problematic because the p- and m-isomers have distinctly different pharmacological and metabolic activities. Two liquid chromatographic (LC) methods have been developed for the baseline separation and quantitation of p- and m-synephrine in bitter orange-containing supplements. An isocratic LC method that utilizes ultraviolet (UV) absorbance detection and a gradient LC method that utilizes tandem mass spectrometry (MS/MS) detection were optimized for separation of the isomers within a run time of 25 min. Terbutaline was utilized as an internal standard compound in both LC methods. The LC/UV and LC/MS/MS methods demonstrated limits of quantitation (LOQs) for synephrine of ≈30 ng (on-column) and ≈0.02 ng (on-column), respectively, and each method exhibited analytical linearity over three orders of magnitude. Both LC methods were used to evaluate the synephrine levels in a limited selection of commercially available bitter orange-containing supplements. Significantly, m-synephrine was not detected in any of the tested dietary supplements.