Direct online extraction and determination by supercritical fluid extraction with chromatography and mass spectrometry of targeted carotenoids from red Habanero peppers (Capsicum chinense Jacq.)

Recently, supercritical fluid chromatography coupled to mass spectrometry has gained attention as a fast and useful technology applied to the carotenoids analysis. However, no reports are available in the literature on the direct online extraction and determination by supercritical fluid extraction with chromatography and mass spectrometry. The aim of this research was the development of an online method coupling supercritical fluid extraction and supercritical fluid chromatography for a detailed targeted native carotenoids characterization in red habanero peppers. The online nature of the system, compared to offline approaches, improves run‐to‐run precision, enables the setting of batch‐type applications, and reduces the risks of sample contamination. The extraction has been optimized using different temperatures, starting from 40°C up to 80°C. Multiple extractions, until depletion, were performed on the same sample to evaluate the extraction yield. The range of the first extraction yield, carried out at 80°C, which was the best extraction temperature, was 37.4–65.4%, with a %CV range of 2–12. Twenty‐one targeted analytes were extracted and identified by the developed methodology in less than 17 min, including free, monoesters, and diesters carotenoids, in a very fast and efficient way. Quantification of the β‐carotene was carried out by using the optimized conditions.     

Rapid isocratic HPLC analysis of beta-carotene in red peppers (Capsicum annuum L.) and food preparations

Summary A simple, rapid high-performance liquid chromatography method has been devised in order to separate and quantify β-carotene present in red pepper (Capsicum annuum L.) fruits and food preparations. A reversed-phase isocratic non-aqueous system enables the separation of β-carotene within a few minutes, with detection at 450 nm. The selection of extraction solvents, mild saponification conditions, and chromatographic features, is evaluated and discussed. The method is proposed for rapid screening of large plant populations, plant selection, as well as for food products, and also for nutrition and quality control studies.     

Open‐tubular capillary electrochromatographic application of a sol‐gel matrix with chilli peppers,garlic, or synthetic additives

This article describes a possible combination of two promising fields of analytical chemistry—the preparation of sol‐gel matrices with varying additives and their application in capillary electrochromatography. The inner surfaces of capillaries were coated with the sol‐gel solution containing either pure synthetic chemical additive—alliin or capsaicin—or an extract of their natural sources—garlic and chilli pepper, respectively. The modified capillaries were tested for interaction with two neurotransmitters, oligopeptides and nucleotides under conditions of open‐tubular capillary electrochromatography. Because both of the natural extracts also contain vitamin C and saccharose, the capillaries with sol‐gel modifiers containing each of these substances were also tested. The obtained results from the perspective of changes in the electrochromatograms and the effective mobilities of analytes are discussed with respect to mild conditions both in the preparation process of the sol‐gel matrix and during the separations.     

辣椒挥发性成分研究进展

辣椒是非常重要的蔬菜作物之一,在调味品中占有举足轻重的地位。综述涉及了近年国内外对辣椒挥发性成分研究取得的进展,主要包括品种、成熟程度、产品形式等多种因素对辣椒挥发性成分影响,以及利用气相色谱-闻香器联用仪鉴定出了多种辣椒香味活性成分。研究结果表明,辣椒香气与品种、产地、成熟程度、质量等因素有直接的联系。     

Elucidation of Analytical–Compositional Fingerprinting of Three Different Species of Chili Pepper by Using Headspace Solid-Phase Microextraction Coupled with Gas Chromatography–Mass Spectrometry Analysis,and Sensory Profile Evaluation

The aim of the present study was to determine the volatile compounds of three different species of chili peppers, using solid-phase microextraction (SPME) methods in combination with gas chromatography–mass spectrometry (GC-MS). The detection of marker aroma compounds could be used as a parameter to differentiate between species of chili peppers for their detection and traceability in chili pepper food. The sensorial contribution was also investigated to identify the predominant notes in each species and to evaluate how they can influence the overall aroma. Three different pepper species belonging to the Capsicum genus were analyzed: Chinense, Annuum, and Baccatum. A total of 269 volatile compounds were identified in these species of chili peppers. The Capsicum annum species were characterized by a high number of acids and ketones, while the Capsicum chinense and Capsicum baccatum were characterized by esters and aldehydes, respectively. The volatile profile of extra virgin olive oils (EVOOs) flavored with chili peppers was also investigated, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the volatile profiles were demonstrated to be a powerful analytical strategy for building a model that highlights the potential of a volatile characterization approach for use in evaluating food traceability and authenticity.     

The Influence of Lactic Acid Fermentation on Selected Properties of Pickled Red,Yellow, and Green Bell Peppers

Red, yellow, and green peppers are vegetables rich in natural pigments. However, they belong to seasonal vegetables and need to be treated to prolong their shelf life. One new approach to processing vegetables is to pickle them using lactic acid bacteria. The use of such a process creates a new product with high health value, thanks to the active ingredients and lactic acid bacteria. Therefore, this study aimed to evaluate the effect of the applied strain of lactic acid bacteria (LAB) on the chemical properties, including the content of active compounds (pigments) and the physical properties of the peppers. Levilactobacillus brevis, Limosilactobacillus fermentum, and Lactoplantibacillus plantarum were used for fermentation and spontaneous fermentation. The pigments, polyphenols content, and antioxidant properties were determined in the pickled peppers, as well as sugar content, color, dry matter, texture properties, and the count of lactic acid bacteria. In all samples, similar growth of LAB was observed. Significant degradation of chlorophylls into pheophytins was observed after the fermentation process. No significant differences were observed in the parameters tested, depending on the addition of dedicated LAB strains. After the fermentation process, the vitamin C and total polyphenols content is what influenced the antioxidant activity of the samples. It can be stated that the fermentation process changed the red bell pepper samples in the smallest way and the green ones in the highest way.     

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.     

从干红辣椒中提取辣椒红色素的研究

辣椒红色素是天然红色素的一种,可从干红辣椒中提取。文中对有机溶剂从干红辣椒中提取辣椒红色素进行了研究。考察了质量分数为95%酒精,石油醚和丙酮对辣椒红色素提取的影响,结果表明丙酮为最优的提取溶剂。通过正交实验确定丙酮提取的最优条件为：每次提取时间为3h,提取温度为30 ℃,提取每克辣椒所用溶剂总量为25 mL,提取次数为3次。     

Characterization of the pigment fraction in sweet bell peppers (Capsicum annuum L.) harvested at green and overripe yellow and red stages by offline multidimensional convergence chromatography/liquid chromatography–mass spectrometry

Offline multidimensional supercritical fluid chromatography combined with reversed‐phase liquid chromatography was employed for the carotenoid and chlorophyll characterization in different sweet bell peppers (Capsicum annuum L.) for the first time. The first dimension consisted of an Acquity HSS C₁₈ SB (100 × 3 mm id, 1.8 μm particles) column operated with a supercritical mobile phase in an ultra‐performance convergence chromatography system, whereas the second dimension was performed in reversed‐phase mode with a C₃₀ (250 × 4.6 mm id, 3.0 μm particles) stationary phase combined with photodiode array and mass spectrometry detection. This approach allowed the determination of 115 different compounds belonging to chlorophylls, free xanthophylls, free carotenes, xanthophyll monoesters, and xanthophyll diesters, and proved to be a significant improvement in the pigments determination compared to the conventional one‐dimensional liquid chromatography approach so far applied to the carotenoid analysis in the studied species. Moreover, the present study also aimed to investigate and to compare the carotenoid stability and composition in overripe yellow and red bell peppers collected directly from the plant, thus also evaluating whether biochemical changes are linked to carotenoid degradation in the nonclimacteric investigated fruits, for the first time.