Pepper is a crucial vegetable as well as spice crop, fruits of which contain numerous bioactive compounds such as capsaicinoids, capsinoids, carotenoids, and oleoresin. Because of the increased ...demand for eco-friendly products, increasing attention has been paid toward the bioactive compounds in pepper. Hot pepper fruits have potential applications in the pharmaceutical and cosmeceutical industries. Thus, suitable varieties or F1 hybrids rich in bioactive compounds must be developed, which requires breeders to have knowledge on available genetic resources, gene action, and molecular markers associated with these traits. The large variability in the bioactive compounds in hot pepper germplasm and novel generation sequencing technologies have enabled understanding, precise mapping, and marker-assisted selection through single nucleotide polymorphism markers. The present study reviews the available knowledge on various industrial applications of hot peppers, genetic resources and progress made on marker development, and breeding for industrial uses of hot pepper globally.
•Peppers have wide applications in pharmaceutical and cosmeceutical industries.•Genetic resources with high capsacinoids, capsinoids and carotenoids are available.•Several efficient estimation methods of the compounds are available.•Molecular markers and candidate genes information for use in marker assisted selection.
•RNA-sequencing was used to assess transcriptome changes associated with fluctuation of the pungency in chili pepper fruits.•Pungent fluctuation was associated with changes in gene expressions ...responsible for metabolic pathways around the biosynthesis of capsaicinoids.•Clustering analysis in genes related to transcriptional regulation was performed using disclosed RNA sequencing data.•The nine genes were noted to exhibit expression patterns similar to those of capsaicinoid biosynthesis genes.•Transcript levels in most of these nine genes were proportional to the pepper pungency levels and are inferred to contribute to the fluctuation of pungency.
Chili peppers (Capsicum spp.) are a popular horticultural crop; the characteristic hot taste of chili peppers is the result of a class of compounds called capsaicinoids. In the horticultural production of such peppers, fluctuations in pungency (changes in capsaicinoid content) are an important issue, given that this fluctuation can cause confusion in the distribution or deterioration of pepper quality. Here, we sought to clarify the mechanism of this variation in pungency, specifically by investigating this variation at the transcriptome level. In the present study, we used the pungency-variable sweet chili pepper ‘Shishito’ (C. annuum) and created high-pungency seedless fruits by parthenocarpic treatment. RNA-sequencing analysis then was used to comprehensively compare gene expression in these fruits with that in less-pungent seeded fruits. We firstly profiled differentially expressed genes (DEGs) contributing to metabolic pathways involved with capsaicinoid biosynthesis. Subsequently, we employed clustering analysis (using previously published RNA-sequencing data) to explore changes in the expression of genes encoding putative transcription factors that might serve as regulators of the capsaicinoid biosynthesis genes (CABGs). Specifically, we screened nine DEGs (CaMYB31, WRKY9, TF62308, TF60920, TF62062, TF75838, ACOT9, TF62804, and TF64623) that have gene ontology related to the regulation of transcription, and found that the expression patterns of these DEGs were similar to those of several CABGs. We also employed quantitative reverse transcriptional polymerase chain reaction to investigate the expression (in the pungency-varied fruits) of these DEGs with putative roles in transcription. Accordingly, we observed that the transcript levels in most of these DEGs correlated positively with the amount of capsaicinoid in the placental septum. Therefore, we postulate that these DEGs with putative transcriptional regulatory roles are involved in capsaicinoid biosynthesis, such that the transcript levels of these DEGs may contribute to the fluctuation of pepper pungency.
Red pepper oil is a flavored oil produced at home and in restaurants. Most red pepper oil is manufactured by extraction at a high temperature, which can produce harmful substances, such as ...acrylamide. Acrylamide, a toxic substance classified as a probable human carcinogen, is formed when foods are cooked at high temperatures above 120 °C. In this study, we aimed to propose the optimal method to produce red pepper oil with a decreased amount of acrylamide while maintaining quality characteristics. The conventional cooking (CC) method (160, 180, and 200 °C) and microwave cooking (MC) method were used to make red pepper oil. The acrylamide, carotenoids, and capsaicinoids contents increased with temperature and time. The maximum and minimum acrylamide content of red pepper oil was 3,494.00 ± 147.81 ppb after CC at 200 °C for 5 min and 131.78 ± 2.93 ppb after CC at 160 °C for 1 min, respectively. The total carotenoid contents of the CC samples ranged from 3.74 ± 0.01 to 4.47 ± 0.04 mg/g. Capsaicin and dihydrocapsaicin contents of CC samples ranged from 3.03 to 4.44 and from 1.33 to 1.92 mg/g, respectively. The total carotenoid and capsaicinoid contents of the MC sample were significantly higher than that of CC samples (p < 0.05). In the results of sensory evaluation for 4 samples (CC at 160, 180, and 200 °C, and MC), the sample with the highest score for all attributes was the MC sample. Based on the results of this study, the MC method is considered as an optimal condition for producing red pepper oil with a low acrylamide content and desirable quality characteristics.
•Red pepper oil is a flavored oil produced at home and in restaurants.•Red pepper oil is produced by hot oil extraction, which can produce acrylamide.•Conventional and microwave cooking method were used to make red pepper oils.•Acrylamide, carotenoid, and capsaicinoid in oil increased with temperature and time.•Microwave cooking was considered as an optimal condition to make a red pepper oil.
Novel voltammetric approach for the selective determination of total capsaicinoids has been developed using glassy carbon electrode modified with multi‐walled carbon nanotubes and poly(gallic acid) ...(PGA/MWNT/GCE). The modified electrode provides significant improvements in the capsaicinoids voltammetric characteristics in comparison to GCE and MWNT/GCE. The electrooxidation of capsaicinoids is irreversible adsorption‐controlled process with the anodic transfer coefficient of 0.49–0.53 and heterogeneous electron transfer rate constant of 1300–2400 s−1. The analytical ranges of 0.010–1.0 and 1.0–50 μM for capsaicin, 0.025–0.75 and 0.75–75 μM for dihydrocapsaicin and 0.025–5.0 and 5.0–75 μM for nonivamide with the detection limits of 2.9, 5.9 and 6.1 nM, respectively, have been obtained using differential pulse voltammetry (DPV). The selectivity of the capsaicinoids quantification in the presence of ascorbic acid, α‐tocopherol and carotenoids is shown. The method has been tested on the samples of red hot pepper spices and Capsicum annuum L. tinctures. The results correspond to the chromatographic data.
•Phytocompounds influence molecular, cellular and systemic pathways.•Phytocompounds also modulate Aquaporins, a family of membrane channel proteins.•Gender differences govern the interaction between ...phytochemicals and AQPs.•Phytocompounds acting on AQP expression and function will make clinical benefits.
A series of plant-derived bioactive compounds belonging to the class of polyphenols, terpenes and capsaicinoids, interact with important pathophysiological pathways at a molecular, cellular and systemic level. Mechanisms of action include altering cell growth and differentiation, apoptosis, autophagy, inflammation, redox balance and metabolic and energy homeostasis. These effects might also involve the expression and function of Aquaporins (AQPs), a family of membrane channel proteins, involved in several body functions. The ultimate translational beneficial effect of such phytocompounds on AQPs in health and disease is a matter of intensive research. Results might provide novel therapeutic approaches to a number of human diseases. Here, we give an updated overview of this fast growing and promising field, discussing a number of phytocompounds and their action on AQPs and related potential clinical achievements.
At specific vibration frequencies like ones generated by insects such as caterpillar chewing and bee's buzz-pollination turn on the plants secondary metabolism and their respective pathways gets ...activated. Thus, studies report that vibrations and sound waves applied to plants improves their fitness performance. Commonly, acoustic treatments for plants have used arbitrarily random frequencies. In this work, a group of signals obtained from hydric-stressed plants was recorded as vibrational patterns using a laser vibrometer. These vibration-signals were classified as representative of each condition and then externally applied as Acoustic Emission Patterns (AEP). The present research hypothesized that specific vibration frequencies could “emulate” a plant signal through mechanical energy based on tplant's ability to recognize vibration pattern similarity to a hydric status. This investigation aimed to apply the AEP's as characteristic vibrations classified as Low hydric stress (LHS), medium hydric stress (MHS), and high hydric stress (HHS) to evaluate their effect on healthy-well watered plants at two developmental stages.
In the vegetative stage, the gene expression related to antioxidant and hydric stress responses was assessed. The LHS, MHS, and HHS acoustic treatments up-regulated the peroxidase (Pod) (~2.8, 1.9, and 3.6-fold change, respectively). The superoxide dismutase (Mn-sod) and phenylalanine ammonia-lyase (Pal) genes were up-regulated by HHS (~0.23 and ~0.55-fold change, respectively) and, the chalcone synthase (Chs) gene was induced by MHS (~0.63-fold-change). At the fructification stage, the MHS treatment induced a significant increase in Capsaicin content (5.88-fold change), probably through the at3and kas gene activation. Findings are correlated for a better understanding of plant responses to different multi frequency-signals tones from vibrations with potential for agricultural applications.
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•Plants change their vibrational frequency pattern according to their hydric stress level.•Acoustic emission patterns (AEP) have the potential to emulate hydric-stress signals on healthy plants. .•AEP externally applied can trigger transcriptional changes in antioxidant responses.•AEP has the possible recreate self-adjustment on osmoregulation in plants through aquaporin and proline.•AEP induces an increase in the capsaicinoids synthesis and at3 and kas up-regulation pathway. .
Chipotle pepper is a dry smoked red Jalapeño pepper well appreciated in the Mexican and American cuisines. Phytochemical content and antioxidant activity of red Jalapeño pepper has been previously ...reported, however, the effect of the smoking process in the content of phytochemicals, antioxidant capacity and capsaicinoids has not been previously reported. In the present study we found that the smoking process had a significant effect on the content of polyphenolic compounds and antioxidant capacity of red Jalapeño pepper. It induced a nearly 50% increase in total phenols and 15% increase in antioxidant capacity in chipotle pepper compared to fresh samples (in dry weight basis). Capsaicinoids and ascorbic acid content decreased in smoked samples, while carotenoids remained practically unchanged. The strongest effect of smoking was observed in the content of total flavonoids and catechin determined by HPLC. Therefore we can conclude that smoking process has a positive effect in the fruit because it raises its phytochemical properties. The type of wood used in the smoking process also had an effect on the phytochemical content and antioxidant capacity with traditional pecan wood being the best.
•Total phenols and flavonoids of red Jalapeño peppers increased during smoking•Antioxidant capacity of red Jalapeño peppers increased during smoking•Capsaicinoids and ascorbic acid content decreased in smoked samples•The strongest effect of smoking was observed in the content of total flavonoids•Peppers smoked with pecan firewood showed the highest content of phytochemicals
Kimchi, a traditional Korean food manufactured using various vegetables and other ingredients, such as garlic, ginger, and red pepper, imparts several health benefits. However, the variation in the ...bioactive compounds responsible for the health benefits of various kimchis is not well-characterized. Here, we analyzed the bioactive profile of eight kimchis, prepared using different vegetables as the main ingredient. We compared the major phytochemical compositions, including glucosinolates, carotenoids, capsaicinoids, chlorophylls, and ascorbic acid contents in Baechu-kimchi (BC) and Baek-kimchi (BK) prepared using napa cabbage, Gat-kimchi (GT) prepared using mustard leaf, Kkakdugi (KD), Chonggak-kimchi (CGK), and Yeolmu-kimchi (YM) prepared using radish, Pa-kimchi (PA) prepared using green onion, and Oi-sobagi (OB) prepared using cucumber. Among glucosinolates, 4-methoxyglucobrassicin was abundant in BC and BK, wherein 4-methoxyglucobrassicin and glucoraphasatin were dominant in CGK, YM, and KD. The glucosinolate breakdown product ascorbigen was abundant in all kimchi. Carotenoids, particularly capsanthin from red chili pepper, were the highest in PA. YM and PA showed high chlorophyll contents, and ascorbic acid contents were almost two-fold higher in GT than in OB and BK. Total capsaicinoids, which confer pungency, were highest in OB. PA, GT, and no capsaicinoid were detected in BK, which contained no red chili pepper powder.
•The main vegetable ingredient determines the phytochemical composition of kimchi.•The glucosinolates’ breakdown product, ascorbigen, is abundant in all kimchi.•Red chili pepper contributes to the carotenoid and capsanthin contents in kimchi.•Red chili pepper powder determines the capsaicinoid contents in kimchi.•Chlorophyll contents vary with the ripening stage and pH of kimchi.
Increasing the crop quality through enhancement of plant health is a challenging task. In this study, nanoselenium (nano-Se) was sprayed on pepper leaves, and the pepper components were compared to ...those of selenite. It was found that nano-Se (20 mg/L) resulted in a greater performance of plant health. It increased the chlorophyll and soluble sugar levels, which could activate phenylpropane and branched-chain fatty acid pathways, as well as
related enzymes and gene expressions. These led to an enhancement for the synthesis of capsaicinoids, flavonoids, and total phenols. The nano-Se treatment also significantly promoted the expression of phyto-hormones synthesis genes, and consequently increased jasmonic, abscisic, and salicylic acid levels. Proline pathway-related compounds were increased, which could decrease the malondialdehyde and hydroxyl radical levels in crops. This study shows that nano-Se activated capsaicinoid pathways by enhancing photosynthesis and raising soluble sugar levels. The capsaicinoid contents in peppers were then increased, which consequently promoted the accumulation of secondary metabolites and antioxidants.
•Co-milling of fresh chili peppers and olives was proposed for flavouring of olive oil.•Oils obtained by co-milling and infusion showed similar capsaicinoids profiles.•Oils from infusion were rich in ...acetic acid and presented the winey/vinegary defect.•Oils from co-milling were characterized by volatile esters and were free from defects.•Co-milling with red or green chili determined different sensory and volatile profiles.
In the context of the olive oil flavoured with chili peppers, the aim of this study was to compare co-milling of sound olives and fresh chili peppers at mill scale to infusion of dried chili peppers in oil, using the same batch of olives for all oils. Capsaicinoids by HPLC-DAD, volatile profile by HS-SPME-GC-MS and HS-GC-IMS and sensory profile were characterized. Capsaicinoids were statistically higher in oils prepared with green (52.0–68.0 mg/kg) than red (48.0–60.2 mg/kg) chili peppers. Oils flavoured by infusion showed higher contents of volatile compounds linked to defects such as acetic acid, with winey/vinegary sensory defect (median, 1.72–2.02) and no fresh pepper flavour. Oils prepared by co-milling resulted rich in the typical esters of chili pepper (6.175 and 4.156 mg/kg with green and red chili peppers, respectively), with pleasant hotness sensation and fresh pepper flavour. Overall, the co-milling approach allowed obtaining flavoured samples with improved sensory quality.
