Capsaicinoids in Chili Habanero by Flow Injection with Coulometric Array Detection

Multi-dimensional pungency and sensory profiles of powder and oil of seven chili peppers based on descriptive analysis and Scoville heat units

The pungency and flavor experience of peppers determines their economic benefits and consumption; thus, a systematic sensory evaluation of peppers is essential to monitor their production. Here the Scoville heat units (SHUs) of powders and oils of seven commercial peppers in China (i.e., Indian, Erjintiao, Shizhuhong, Zidantou, Xinyidai, Mantianxing and Denglong) were derived based on concentrations of capsaicin and dihydrocapsaicin. Then, the pungency and sensory profiles of pepper products were investigated by 11 trained panelists. The potential indicators for predicting perceived pungency in peppers were found based on correlation analysis. The Indian pepper stood out for its highest SHU (85909), bright redness, peppery, and bitterness, but lacked herb/woody flavor. But other species had more varied flavor profiles and gentler mouth-feelings. SHU and capsaicin were more recommended in predicting the perceived pungency in pepper powder and pepper oil. This study offers a framework for evaluating the sensory characteristics of pepper products.

Genetic Regulation, Environmental Cues, and Extraction Methods for Higher Yield of Secondary Metabolites in Capsicum

Capsicum (chili pepper) is a widely popular and highly consumed fruit crop with beneficial secondary metabolites such as capsaicinoids, carotenoids, flavonoids, and polyphenols, among others. Interestingly, the secondary metabolite profile is a dynamic function of biosynthetic enzymes, regulatory transcription factors, developmental stage, abiotic and biotic environment, and extraction methods. We propose active manipulable genetic, environmental, and extraction controls for the modulation of quality and quantity of desired secondary metabolites in Capsicum species. Specific biosynthetic genes such as Pun (AT3) and AMT in the capsaicinoids pathway and PSY, LCY, and CCS in the carotenoid pathway can be genetically engineered for enhanced production of capsaicinoids and carotenoids, respectively. Generally, secondary metabolites increase with the ripening of the fruit; however, transcriptional regulators such as MYB, bHLH, and ERF control the extent of accumulation in specific tissues. The precise tuning of biotic and abiotic factors such as light, temperature, and chemical elicitors can maximize the accumulation and retention of secondary metabolites in pre- and postharvest settings. Finally, optimized extraction methods such as ultrasonication and supercritical fluid method can lead to a higher yield of secondary metabolites. Together, the integrated understanding of the genetic regulation of biosynthesis, elicitation treatments, and optimization of extraction methods can maximize the industrial production of secondary metabolites in Capsicum.

The Genus Capsicum: A Review of Bioactive Properties of Its Polyphenolic and Capsaicinoid Composition

Chili is one of the world's most widely used horticultural products. Many dishes around the world are prepared using this fruit. The chili belongs to the genus Capsicum and is part of the Solanaceae family. This fruit has essential biomolecules such as carbohydrates, dietary fiber, proteins, and lipids. In addition, chili has other compounds that may exert some biological activity (bioactivities). Recently, many studies have demonstrated the biological activity of phenolic compounds, carotenoids, and capsaicinoids in different varieties of chili. Among all these bioactive compounds, polyphenols are one of the most studied. The main bioactivities attributed to polyphenols are antioxidant, antimicrobial, antihyperglycemic, anti-inflammatory, and antihypertensive. This review describes the data from in vivo and in vitro bioactivities attributed to polyphenols and capsaicinoids of the different chili products. Such data help formulate functional foods or food ingredients.

Analysis of Phenolic Compounds in Food by Coulometric Array Detector: A Review

Phenolic compounds are an important group of organic molecules with high radical scavenging, antimicrobial, anti-inflammatory, and antioxidant properties. The emerging interest in phenolic compounds in food products has led to the development of various analytical techniques for their detection and characterization. Among them, the coulometric array detector is a sensitive, selective, and precise method for the analysis of polyphenols. This review discusses the principle of this method and recent advances in its development, as well as trends in its application for the analysis of phenolic compounds in food products, such as fruits, cereals, beverages, herbs, and spices.

Evaluation of the Soil Type Effect on the Volatile Compounds in the Habanero Pepper (Capsicum chinense Jacq.)

The aim of this research was to evaluate the effect of soil on the concentration of the main volatile compounds in the Habanero pepper (Capsicum chinense Jacq.). Plants were cultivated in three soils named, corresponding to the Maya classification, as Chich lu’um (brown soil), Box lu’um (black soil), and K’ankab lu’um (red soil). The volatile compounds of the peppers were extracted by steam distillation, analyzed by gas chromatography, and reported on a fresh weight (FW) basis. The results indicated that the soil presented a significative effect on the concentration of the volatile compounds evaluated (1-hexanol, hexyl-3-methyl butanoate, 3,3-dimethyl-1-hexanol, cis-3-hexenyl hexanoate). The peppers cultivated in black soil exhibited the highest concentration of 1-hexanol (360.14 ± 8.57 µg g−1 FW), 3,3-dimethyl-1-hexanol (1020.61 ± 51.27 µg g−1 FW), and cis-3-hexenyl hexanoate (49.49 ± 1.55 µg g−1 FW). In contrast, the highest concentration of hexyl-3-methyl butanoate (499.93 ± 5.78 µg g−1 FW) was quantified in peppers grown in brown soil. This knowledge helps us to understand the role of the soil in the aroma of the Habanero pepper and could be used by farmers in the region (Yucatan Peninsula) to select the soil according to the desired aroma characteristics.

Determination of Peak Purity in HPLC by Coupling Coulometric Array Detection and Two-Dimensional Correlation Analysis

This work aims to evaluate the purity of chromatographic peaks by a two-dimensional correlation (2D-corr) analysis. Such an analysis leads to two contour plots: synchronous and asynchronous. The synchronous contour plot provides information on the number of peaks present in the chromatogram. The asynchronous contour plot reveals the presence of overlapping species on each peak. The utility of 2D-corr analysis was demonstrated by the chromatographic analysis of Capsicum chili extracts obtained by HPLC coupled with a coulometric array of sixteen detectors. Thanks to 16 electrochemical sensors, each poised at increasing potentials, the resulting 2D-corr analysis revealed the presence of at least three species on the peak located at a retention time of 0.93 min. Mass spectrometry (MS) analysis was used to analyze the coeluting species, which were identified as: quinic acid (3.593 min), ascorbic acid (3.943 min), and phenylalanine (4.229 min). Overall, this work supports the use of 2D-corr analysis to reveal the presence of overlapping compounds and, thus, verify the signal purity of chromatographic peaks.

Electroanalytical overview: the pungency of chile and chilli products determined via the sensing of capsaicinoids

When you bite into a chile pepper or eat food containing chile (chilli), one might feel heat, or other associated feelings, some good such as the release of endorphins, and some bad. The heat, or pungency, and related feelings from eating chile peppers are the result of their chemical composition, i.e. the concentrations of capsaicinoids. The major components are capsaicin and dihydrocapsaicin, which occur in chiles in the ratio of 6 : 4. Other capsaicinoids occur in smaller concentrations and are known as the "minor" capsaicinoids. Wilbur L. Scoville in 1912 created an organoleptic test, now known as the Scoville scale, which asked a panel of tasters to state when an increasingly dilute solution of the chile pepper in alcohol no longer burned the mouth. Following the Scoville scale, a plethora of analytical techniques later followed. In this overview, we explore the endeavours directed to the development of electrochemical-based sensors for the determination of capsaicin and related compounds, starting from their use in hyphenated laboratory set-ups to their modern use as stand-alone electroanalytical sensors. The latter have the advantage of providing a rapid and sensitive methodology that has the potential to be translated in the field; future trends and issues to be overcome are consequently suggested.

Analytical Capabilities of Coulometric Sensor Systems in the Antioxidants Analysis

The definition of antioxidants (AOs), their classification and properties as well as electrochemical sensor systems for AOs analysis are briefly discussed. The analytical capabilities of coulometric titration with electrogenerated titrants as sensor systems for AOs determination have been considered in detail. The attention focused on the individual AO quantification that was mainly used in the pharmaceutical analysis and estimation of total antioxidant parameters (total antioxidant capacity (TAC), ferric reducing power (FRP) and ceric reducing/antioxidant capacity (CRAC)) allowing the fast screening of the target samples including their quality control. The main advantages of coulometric sensor systems are pointed out. The selective quantification of individual AO in a complex matrix using a combination of chromatography with coulometric or coulometric array detection under potentiostatic mode is discussed. The future development of coulometric sensor systems for AOs analysis is focused on the application of novel coulometric titrants and the application of coulometric detection in flow injection analysis.

Phytochemical Characterization of By-Products of Habanero Pepper Grown in Two Different Types of Soils from Yucatán, Mexico

By-products of edible plants may contain potentially useful phytochemicals. Herein, we valorized the by-products of Capsicum chinense by phytochemical characterization of its leaves, peduncles and stems. Plants of habanero pepper were grown in a greenhouse, in polyethylene bags with two soils that were named according to the Maya classification as: K'ankab lu'um (red soil) and Box lu'um (black soil). Habanero pepper by-products were dried using an oven, the extracts were obtained by Ultrasound Assisted Extraction, and phytochemical quantification in all the extracts was conducted by Ultra Performance Liquid Chromatography coupled to Diode Array Detector (UPLC-DAD). Differences in the phytochemical content were observed according to the by-product and soil used. Catechin and rutin showed the highest concentrations in the peduncles of plants grown in both soils. The leaves of plants grown in black soil were rich in myricetin, β-carotene, and vitamin E, and the stems showed the highest protocatechuic acid content. While the leaves of plants grown in red soil were rich in myricetin and vitamin C, the stems showed the highest chlorogenic acid content. This novel information regarding the phytochemical composition of the by-products of C. chinense may be relevant in supporting their potential application in food and pharmaceutical industries.