Characterization of Red Peppers (Capsicum annuum) by High-performance Liquid Chromatography and Near-infrared Spectroscopy

Dehydration of peppers (Capsicum annuum) is a widely used preservation method. In this study, sun- and hot air-dried red peppers were analyzed for American Spice Trade Association color units, capsaicin, dihydrocapsaicin, organic acids, and free sugars by high-performance liquid chromatography (HPLC), and soluble solids by near-infrared spectroscopy (NIR). In the validation of HPLC protocols, the relative standard deviations were less than 5%, fulfilling the required criteria of Association of Official Analytical Chemists. The concentrations of capsaicin (80.4?mg kg^?1), dihydrocapsaicin (38.0?mg kg^?1), lactic acid (85.2?mg/100?g), glucose (1.521%), and fructose (3.463%) were slightly higher in sun-dried peppers. Linear discriminant analysis showed that NIR spectroscopy is more useful in discriminating sun- and hot air-dried pepper samples.     

Die Skala des Wilbur Lincoln Scoville. Manche mögen's scharf

All species of the genus capsicum are very popular food ingredients in most parts of the world. The biochemistry of Bell Pepper and Chili has many surprises to offer. The brilliant red color is based on the “paprika ketones, " compounds that only capsicum can synthesize. The extraordinary pungency, which many humans enjoy so much, is due to capsaicin and dihydrocapsaicin, which are also compounds that only capsicum can produce. After analyzing capsicums' unique and outstanding chemistry, we should enjoy peppers, chilis, Jalapeños, and Habaneros definitely with more respect because of their chemical achievements.     

Studies on the synthesis, pungency and anti-biofouling performance of capsaicin analogues

Ten capsaicin analogues were synthesized and their pungency degrees were determined through Scoville Organoleptic Test.The relationship between the structure and pungency degree of these capsaicin analogues was discussed.Then four of these capsaicin analogues with higher pungency degree were picked out and added to anti-biofouling paints as repellents to study their anti-biofouling performance by shallow sea buoyant raft hung-plate experimentation.The results showed that capsaicin and dihydrocapsaicin exhibited equally good anti-biofouling performance while nordihydrocapsaicin and N-vanillylnonanamide had poor anti-biofouling performance.Experimental results also showed that the paints with only 0.1% capsaicin or dihydrocapsaicin as repellent without any other biocides had also exhibited good anti-biofouling performance,which provided a new idea for developing novel,more environment-friendly and Cu2O-free antifouling paints.     

辣椒素同系物合成、辣度及海洋生物防污性能研究

合成了十种辣椒碱同系物,用感官评定的方法对其辣度进行了测定,并将它们的结构与辣度进行了对比,探讨了影响辣椒碱同系物辣度的结构因子.选取其中辣度较大的四种辣椒碱同系物作为海洋生物防污涂料的驱赶剂,考察了它们的海洋生物防污性能.结果表明,辣椒碱和二氢辣椒碱都具有良好的防污性能,二者不相上下.降二氢辣椒碱和壬酸香草胺的防污性能与辣椒碱和二氢辣椒碱有明显区别.仅以辣椒碱或二氢辣椒碱为驱赶剂,且其含量仅为0.1%的情况下,漆膜也表现出较好的防污性能,这为研发新型的、环保的、不含氧化亚铜的防污涂料提供了新思路.     

Analysis of capsaicin and dihydrocapsaicin in peppers and pepper sauces by solid phase microextraction–gas chromatography–mass spectrometry

A simple method for the analysis of capsaicin and dihydrocapsaicin in peppers and pepper sauces by solid phase microextraction–gas chromatography–mass spectrometry has been developed. A novel device was designed for direct extraction solid phase microextraction in order to avoid damage to the fiber. The analysis was performed without derivatization for the gas chromatography–mass spectrometry analysis. Selection fiber, extraction temperature, extraction time and pH, were optimized. The method was linear in the range 0.109–1.323 μg/mL for capsaicin and 0.107–1.713 μg/mL for dihydrocapsaicin with correlation coefficient up to r = 0.9970 for both capsaicinoids. The precision of the method was less than 10%. The method was applied to the analysis of 11 varieties of peppers and four pepper sauces. A broad range of capsaicin (55.0–25 459 μg/g) and dihydrocapsaicin (93–1 130 μg/g) was found in the pepper and pepper sauces samples (4.3–717.3 and 1.0–134.8 μg/g), respectively.     

Lead contamination in selected foods from Riyadh city market and estimation of the daily intake

This study was carried out to determine lead contamination in 104 of the representative food items in the Saudi diet and to estimate the dietary lead intake of Saudi Arabians. Three samples of each selected food items were purchased from the local markets of Riyadh city, the capital of Saudi Arabia. Each pooled sample was analyzed in triplicate by ICP-AES after thorough homogenization. Sweets (0.011-0.199 μg/g), vegetables (0.002-0.195 μg/g), legumes (0.014-0.094 μg/g), eggs (0.079 μg/g), meat and meat products (0.013-0.068 μg/g) were the richest sources of lead. Considering the amounts of each food consumed, the major food sources of lead intake for Saudi can be arranged as follows: vegetables (25.4%), cereal and cereal products (24.2%), beverages (9.7%) sweets (8.2%), legumes (7.4%), fruits (5.4%) milk and milk products (5.1%). The daily intake of lead was calculated taking into account the concentration of this element in the edible part of the daily consumption data which were derived from two sources, (a) the KSA food sheet provided by the Food and Agriculture Organization (FAO) and (b) from questionnaires distributed among 300 families in Riyadh city. The results showed that the daily intakes of lead according to the two sources are 22.7 and 24.5 μg/person/day respectively, which are lower than that mentioned by The Joint Expert Committee on Food Additives (JECFA), whereas it is comprabale with that of other countries.     

Green approach to the extraction of major capsaicinoids from habanero pepper using near-infrared,microwave, ultrasound and Soxhlet methods,a comparative study

A simple method for the extraction of two major capsaicinoids from habanero peppers, using near-infrared irradiation, microwave irradiation or ultrasound as the energy source and ethanol as the solvent, was compared with Soxhlet extraction. The extraction processes were monitored by gas chromatography/mass spectrometry. The new processes offer better overall yields and a higher ratio of capsaicin to dihydrocapsaicin than Soxhlet extraction. The physical effect of the different energy sources on the peppers was determined using scanning electron microscopy. Extraction of capsaicin and dihydrocapsaicin using near-infrared irradiation, which has not been previously reported, was shown to be a simple and efficient alternative extraction procedure.     

Antihyperglucolipidaemic and anticarbonyl stress properties in green,yellow and red sweet bell peppers (Capsicum annuum L.)

Effect of aqueous methanol extract of different colour sweet bell peppers (Capsicum annuum L.) on parameters of diabesity and carbonyl stress was analysed in vitro. Yellow pepper displayed significantly (p < 0.001) higher intestinal α-glucosidase inhibitory activity than green and red pepper. Porcine pancreatic lipase inhibitory activity was significantly (p < 0.01) high in yellow and red pepper than in green pepper. Green and red pepper inhibited vesperlysine-type advanced glycation end products (AGEs) more potently than yellow pepper; however, pentosidine-type AGEs were similarly inhibited by all three peppers. Yellow and red pepper inhibited lipid peroxidation more potently (p < 0.01) than green pepper. Total polyphenol content and free radicals scavenging activities in yellow and red bell peppers were higher than in green pepper. Total flavonoid content was high in green pepper than that present in yellow and red peppers. Green pepper displayed presence of proanthocyanins; however, oligomeric anthocyanins were detected in yellow and red peppers.     

Construction of on-line supercritical fluid extraction with reverse phase liquid chromatography–tandem mass spectrometry for the determination of capsaicin

A column-switching system, composed of supercritical fluid extraction (SFE) and reverse phase liquid chromatography/mass spectrometry (RPLC/MS) was constructed for on-line extraction and reverse-phase separation of capsaicinoids in capsicum fruits.     

Separation and Quantitative Analysis of Capsaicinoids in Chili Peppers by Reversed-Phase Argentation LC

A reversed-phase argentation liquid chromatographic method has been achieved for the separation and determination of capsaicinoids (capsaicin, dihydrocapsaicin and nordihydrocapsaicin) in chili peppers. Capsaicinoids are determined on a C18 column with methanol–water (60:40, v/v) containing 0.03 mol L^?1 silver nitrate as eluent and with ultraviolet detection at 280 nm. Three capsaicinoids are successfully separated from each other and from other interfering components by the high selectivity of reversed-phase argentation LC. The average recovery of the method is around 97%. Good reproducibility is obtained with relative standard deviations varying from 1.68 to 4.52%. The method was successfully applied to characterize and determine the capsaicin and dihydrocapsaicin in chili peppers.     

Determination of capsaicinoids in Capsicum species using ultra performance liquid chromatography‐mass spectrometry

In the present work, a rapid and sensitive ultra performance liquid chromatography‐mass spectrometry method has been proposed for the analysis of capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin) present in different Capsicum samples. Extraction of capsaicinoids was carried out by liquid–liquid extraction using ethanol as an extracting solvent, while the chromatographic separation was achieved by reversed phase C₁₈ column with gradient mobile phase (solvent A: acetonitrile and solvent B: water with 0.1% formic acid). Under the optimum experimental conditions, the linear ranges were 0.5–50 μg/g with correlation coefficient (r²) >0.999 for each capsaicinoids and detection limits were 0.15, 0.05, 0.06, 0.2, and 0.1 μg/g for nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin, respectively. Run‐to‐run and day‐to‐day precisions of the method with relative standard deviations <1.5% were achieved for all analyzed capsaicinoids. The robustness of the method was determined by utilizing different injection volumes of the extracts. Furthermore, to validate the system robustness, a run of high number of capsaicinoids present in different varieties of Capsicum samples was performed in this study. All the capsaicinoids were separated in a time of less than 9 min by employing the proposed method.     

Preparative separation of capsaicin and dihydrocapsaicin from Capsicum frutescens by high‐speed counter‐current chromatography

Capsaicin and dihydrocapsaicin are two main bioactive components of Capsicum frutescens and are widely used as food additives and drugs in China and India. Due to their similarity in structures, isolation of capsaicin and dihydrocapsaicin with traditional methods such as silica gel column chromatography, normal‐phase thin‐layer chromatography (TLC) becomes difficult. This study involves separating capsaicin and dihydrocapsaicin with sufficient purity and recovery using high‐speed counter‐current chromatography (HSCCC) with a solvent system composed of n‐hexane–ethyl acetate–methanol–water–acetic acid (20:20:20:20:2, v/v/v/v/v). Separation parameters such as sample volume, and sample concentration were first optimized on analytical HSCCC, and then scaled up to preparative HSCCC. 0.65 g capsaicin and 0.28 g dihydrocapsaicin were obtained from 1.2 g crude extract and their purities were 98.5 and 97.8%, respectively. The recoveries of the two compounds were 86.3 and 85.4%, respectively. The purity of the isolated compounds was analyzed by high‐performance liquid chromatography (HPLC) and their structures were identified by ¹H nuclear magnetic resonance (NMR) and ¹³C NMR analysis.     

Rapid method for the determination of capsaicin and dihydrocapsaicin in Gochujang using ultra-high-performance liquid chromatography

A sensitive and specific heating block method coupled with ultra-HPLC (u-HPLC) was developed for the analysis of capsaicin in Gochujang and validated by comparing with a conventional HPLC (AOAC Method 995.03). The method validation parameters yielded good results, including linearity, precision, accuracy, and recovery. The u-HPLC separation was performed on a reversed C18 column (50 x 2 mm id, particle size 2 microm), followed by fluorescence detection (excitation 280 nm, emission 325 nm). Methanol was used as the extracting solvent, and the amount of sample taken was approximately 0.2 g; the optimum amount of extraction solvent and extraction time were 15 mL and 1 h, respectively. The recovery of capsaicin in Gochujang was more than 93%, and the LOD and LOQ of the u-HPLC analysis were 0.05 and 0.16 microg/g for capsaicin and 0.05 and 0.16 microg/g for dihydrocapsaicin. The calibration graphs for capsaicin and dihydrocapsaicin were linear from 0.2 to 10.0 microg/mL for u-HPLC. The interday and intraday precisions (RSD values) were < 6.27%.     

液-液萃取-液相色谱-串联质谱法测定“地沟油”中辣椒碱类化合物及丁香酚

建立了“地沟油”中辣椒碱类化合物(包括辣椒素、二氢辣椒素、合成辣椒素)及丁香酚的液-液萃取及液相色谱-串联质谱(LC-MS/MS)检测方法。“地沟油”中辣椒碱类化合物及丁香酚用甲醇萃取,采用SUPEL COSIL ABZ+Plus dC18色谱柱(150 mm×4.6 mm, 5 μm)分离,电喷雾离子源在正、负离子模式下电离,多反应监测(MRM)模式扫描。对辣椒素、二氢辣椒素、合成辣椒素及丁香酚的检出限分别为0.02、0.03、0.03和0.6 μg/L,且在一定的质量浓度范围内线性良好。同一操作人员与不同操作人员间测定的精密度低于5%。该方法专属性强、灵敏、准确,可以作为“地沟油”的判定标准之一。     

GPC–HPLC–MS/MS法测定食用油中天然辣椒素、二氢辣椒素和合成辣椒素含量

以动植物油脂为实验材料,建立了测定食用油中天然辣椒素、二氢辣椒素和合成辣椒素含量的凝胶渗透色谱–高效液相色谱–串联质谱(GPC–HPLC–MS/MS)法。样品经凝胶渗透色谱净化后,采用液相色谱串联质谱法(HPLC–ESI–MS/MS)分析,多反应监测模式(MRM)下外标法定量。在0.1~5.0μg/L范围内线性良好,天然辣椒素、二氢辣椒素和合成辣椒素的相关系数分别为0.999 6,0.999 8,0.999 8,检出限为0.5μg/kg。在5μg/kg添加水平下,空白加标回收率为71.5%~82.5%,测定结果的相对标准偏差为3.0%~8.3%(n=6)。该方法样品处理过程简便快捷,测定结果准确,可满足实验室大量、快速分析的需求。     

Determination of Capsaicinoids in Red Pepper Products from South Korea by High-Performance Liquid Chromatography with Fluorescence Detection

This study aimed at determining the concentrations of the major capsaicinoids, namely, capsaicin and dihydrocapsaicin, in commonly consumed red pepper products from South Korea. The capsaicinoids were extracted with 95% methanol and determined by high-performance liquid chromatography with florescence detection. The analytical method was validated by quality assurance parameters such as the linearity, limits of detection and quantification, precision, and accuracy. Satisfactory results were obtained in accordance to the specified criteria for application of analytical techniques in food. The concentration of capsaicinoids was the highest for red pepper powder (4.18–139.4?mg/100?g), followed by gochujang (0.93–23.20?mg/100?g), kimchi (0.05–1.16?mg/100?g), and sliced kimchi (0.06–0.88?mg/100?g). Comparing the capsaicinoid contents in samples from different production areas, no significant differences were found. This research concluded that the capsaicinoid content of red pepper products provided valuable information regarding the samples.     

Formation and metabolism of pungent principle of Capsicum fruits. XV. Microdetermination of capsaicin by high-performance liquid chromatography with electrochemical detection

A new, highly sensitive method for quantitative separation and determination of capsaicin and dihydrocapsaicin by high-performance liquid chromatography with electrochemical detection is elaborated. The method employs a Cosmosil 5Ph column eluted with 100 mM potassium dihydrogenphosphate containing 45% acetonitrile (pH 5.0) at a flow-rate of 1.0 ml/min, and an electrochemical detector (at a potential of +750 mV versus the Ag/AgCl electrode). The detection limits for both capsaicin and dihydrocapsaicin were 12 pg (39 fmol) at a signal-to-noise ratio of 3:1. By applying this method, the biological half-life of capsaicin in the rat was investigated.     

Ultrasound-assisted extraction of capsaicinoids from peppers

The development of a rapid, reproducible and simple method of extraction of the majority capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin and homodihydrocapsaicin) present in hot peppers by the employment of ultrasound-assisted extraction is reported. The study has covered four possible solvents for the extraction (acetonitrile, methanol, ethanol and water), the optimum temperature for extraction (10–60 °C), the extraction time (2–25 min), the quantity of sample (0.2–2 g), and the volume of solvent (15–50 mL). Under the optimum conditions of the method developed, methanol is employed as solvent, at a temperature of 50 °C and an extraction time of 10 min. The repeatability and reproducibility of the method (R.S.D. < 3%) have been determined. The capsaicinoids extracted have been analysed by HPLC with fluorescence detection and using monolithic columns for the chromatographic separation. The method developed has been employed for the quantification of the various capsaicinoids present in different varieties of hot peppers cultivated in Spain.     

Scharf,schärfer,Capsaicin!

Capsaicin, the spiciest hot compound known, is a non‐basic alkaloid of chili peppers, belonging to the genus Capsicum. With 16 million units it is on top of the Scoville scale, a measure for the degree of spicy heat within a food. Capsicum, capsaicin and this scale have already been discussed in this journal in 2010. After botanical and culinary aspects, now a method for the separation of the main capsaicinoids, capsaicin and dihydrocapsaicin, is reported which makes use of the complexation of capsaicin by Ag+ ions on an AgNO₃ impregnated silica gel column. All analytical spectra were recorded. They are reproduced either in the main part or in the supporting information and discussed in detail. Calculations of the structure are compared with data of an own x‐ray analysis of capsaicin. The project is a follow up of the recent book “Classics in Spectroscopy” by S. Berger und D. Sicker (Wiley‐VCH 2009).     

高效液相色谱法测定辣椒中的辣椒碱和二氢辣椒碱

建立了高效液相色谱法(HPLC)测定辣椒中辣椒碱、二氢辣椒碱的检测方法.实验考察了仪器条件、不同流动相体系、流动相配比、柱温、流速等因素对分离的影响.确定了最佳色谱条件为ZORBAX SB-C18色谱柱(250mm×4.6 mm,5μm);二极管阵列检测器,辣椒碱、二氢辣椒碱的最佳检测波长为280 nm;色谱柱温度为2...