Antioxidant capacity and total phenolic content in fruit tissues from accessions of Capsicum chinense Jacq. (Habanero pepper) at different stages of ripening

Antioxidant potential and factors influencing the content of antioxidant compounds of pepper: A review with current knowledge

The use of natural food items as antioxidants has gained increasing popularity and attention in recent times supported by scientific studies validating the antioxidant properties of natural food items. Peppers (Capsicum spp.) are also important sources of antioxidants and several studies published during the last few decades identified and quantified various groups of phytochemicals with antioxidant capacities as well as indicated the influence of several pre- and postharvest factors on the antioxidant capacity of pepper. Therefore, this review summarizes the research findings on the antioxidant activity of pepper published to date and discusses their potential health benefits as well as the factors influencing the antioxidant activity in pepper. The major antioxidant compounds in pepper include capsaicinoids, capsinoids, vitamins, carotenoids, phenols, and flavonoids, and these antioxidants potentially modulate oxidative stress related to aging and diseases by targeting reactive oxygen and nitrogen species, lipid peroxidation products, as well as genes for transcription factors that regulate antioxidant response elements genes. The review also provides a systematic understanding of the factors that maintain or improve the antioxidant capacity of peppers and the application of these strategies offers options to pepper growers and spices industries for maximizing the antioxidant activity of peppers and their health benefits to consumers. In addition, the efficacy of pepper antioxidants, safety aspects, and formulations of novel products with pepper antioxidants have also been covered with future perspectives on potential innovative uses of pepper antioxidants in the future.

Antifungal activity of chili pepper extract with potential for the control of some major pathogens in grapevine

BACKGROUND

In recent years, biofungicides have drawn increasing interest in vineyards for a more sustainable integrated and copper-limited pest management. Among alternatives, botanicals could represent valuable tools, being rich sources of biologically active compounds. Conversely to the well-known antioxidant and biological properties in relation to health benefits, investigation on bioactivity of hot pungent Capsicum sp. products against fungal phytopathogens in vineyards is still scarce. Therefore, the present study aimed at exploring the biologically active compounds profile of a chili pepper (Capsicum chinense Jacq.) pod extract and its antimicrobial properties against some of the major fungal and Oomycetes pathogens of grapevine, including Botrytis cinerea Pers., Guignardia bidwellii (Ellis) Viala & Ravaz and Plasmopara viticola (Berk. & M.A. Curtis) Berl. & De Toni.

RESULTS

The ethyl acetate-extracted oleoresin from the most pungent varieties was rich in capsaicinoids and polyphenols (371.09 and 268.5 μg mg-1 dry weight, respectively). Capsaicin and dihydrocapsaicin, hydroxycinnamic and hydroxybenzoic acids and quercetin derivatives were the most abundant, while carotenoids represented only a minor fraction. The oleoresin was efficient to inhibit all three pathogenic fungi and ED50 values were determined, evidencing that G. bidwellii was the more sensitive (0.233 ± 0.034 mg mL-1 ).

CONCLUSION

The results suggested a potentiality of chili pepper extract for the control of some important grapevine pathogens, their possible application being helpful for the recommended limitation in extensive use of copper in vineyard. The complex mixture of high amounts of capsaicinoids, associated to specific phenolic acids and other minor bioactive components might contribute to the observed antimicrobial action of chili pepper extract. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Ripening-Induced Changes in the Nutraceutical Compounds of Differently Coloured Pepper (Capsicum annuum L.) Breeding Lines

To date, several research studies addressed the topic of phytochemical analysis of the different coloured pepper berries during ripening, but none discussed it in the case of purple peppers. In this study we examine whether the anthocyanin accumulation of the berries in the early stages of ripening could result in a higher antioxidant capacity due to the elevated amount of polyphenolic compounds. Therefore, enzymatic and non-enzymatic antioxidant capacity was measured in four distinct phenophases of fruit maturity. Furthermore, the expression of structural and regulatory genes of the anthocyanin biosynthetic pathway was also investigated. An overall decreasing trend was observed in the polyphenolic and flavonoid content and antioxidant capacity of the samples towards biological ripeness. Significant changes both in between the genotypes and in between the phenophases were scored, with the genotype being the most affecting factor on the phytonutrients. An extreme purple pepper yielded outstanding results compared to the other genotypes, with its polyphenolic and flavonoid content as well as its antioxidant capacity being the highest in every phenophase studied. Based on our results, besides MYBa (Ca10g11650) two other putative MYBs participate in the regulation of the anthocyanin biosynthetic pathway.

A Melatonin Treatment Delays Postharvest Senescence, Maintains Quality, Reduces Chilling Injury, and Regulates Antioxidant Metabolism in Mango Fruit

The effects of an exogenous application of various concentrations and dipping duration of melatonin (MT) treatment on postharvest senescence, quality, chilling tolerance, and antioxidant metabolism of mango fruit cv. “Dashehari” were examined. Fruits were treated with three concentrations of MT (50, 100, or 150 µM), each applied for three times (60, 90, or 120 min), followed by storage at 5 ± 1°C. The MT concentration of 100 µM with a dipping duration of 120 min was efficient in reducing the chilling injury and maintaining the quality of mango fruit for 28 d. Effects of this treatment were due to its effectiveness in reducing metabolic activity, specifically, respiration rate and ethylene production, resulting in higher firmness, titratable acidity, and ascorbic acid content and lower weight loss, total soluble solids, pH, and total soluble solid : acidity ratio. Moreover, it maintained a higher concentration of total phenolics and total flavonoids, as well as antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl and cupric reducing antioxidant power assays), as compared to other treatments. This was further confirmed with higher activities of antioxidant enzymes superoxide dismutase and catalase and membrane stability (according to a lower malondialdehyde content and lipoxygenase activity). Thus, our data show that a 100 µM MT administered for 120 min appears to be the most appropriate treatment to maintain the quality of mango fruits stored at chilling temperatures.

Agronomic Performance, Capsaicinoids, Polyphenols and Antioxidant Capacity in Genotypes of Habanero Pepper Grown in the Southeast of Coahuila, Mexico

The genetic improvement program of the Seed Technology Training and Development Center works on the agronomic characterization and the content of bioactive compounds in eight genotypes of habanero pepper. The objective is to select genotypes with good agronomic performance that allow the generation of inbred lines to obtain hybrids. In this study, the agronomic performance and the content of bioactive compounds (capsaicinoids, polyphenols, and antioxidant capacity) were evaluated in eight genotypes of habanero pepper grown in the southeast of Coahuila, Mexico, identified as HNC-1, HNC-2, HNC-3, HNC-4, HNC-5, HNC-6, HNC-7, and HCC-8. The plants were grown in a greenhouse for 127 days, under a completely randomized design with four replications each. The results revealed that the yield (g·plant−1) and number of fruits per plant did not show significant differences between genotypes. However, for the fruit length, the genotypes HCC-8, HNC-7, HNC-6, and HNC-5 stood out with over 40 mm, while in equatorial diameter of the fruit, HCC-8, HNC-4, and HNC-2 stood out with 26.45, 26.46, and 25.12 mm, respectively. The results of the chemical analyses allowed us to identify that HNC-5 and HNC-6 had the highest capsaicin concentration (931.38 and 959.77 mg·kg−1), dihydrocapsaicin (434.95 and 445.89 mg·kg−1), Scoville Heat Units greater than 210,000, total phenols (67.54 and 71.15 mg/100 g) and total flavonoids (34.21 and 38.29 mg/100 g), respectively. The HNC-1 and HNC-6 genotypes had the highest carotenoids concentration with 103.96 and 105.07 mg/100 g, and HCC-8 registered the highest anthocyanin content with 22.08 mg C3GE/100 g. The antioxidant capacities showed significant differences (p ≤ 0.05) between genotypes, with a range of 43.22 to 110.39 µmol TE/100 g, 72.37 to 186.56 µmol TE/100 g, and 191.41 to 244.98 µmol TE/100 g for the tests of DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and FRAP (ferric reducing antioxidant power). The results of this research will be used to select habanero pepper genotypes that can be used in genetic improvement programs to increase the productive potential and the content of bioactive compounds in the fruits to expand their applications in the food industry.

Influence of intra and inter species variation in chilies (Capsicum spp.) on metabolite composition of three fruit segments

Twenty-one different cultivars from four different species were examined. The highest dry weight was present in seeds (between 35 and 50%) and the average water content was 60%. Placenta and pericarp contained on average 86% water. Total sugars variation between species was 60%. The most concentrated in the various cultivar pericarps were ascorbic acid ranging from 368.1 to 2105.6 mg/100 g DW and citric acid ranging from 1464.3 to 9479.9 mg/100 g DW. Total phenolic content ranged from 2599.1 mg/100 DW in 'Chilli AS- Rot' to 7766.7 mg/100 g DW in 'Carolina Reaper'. The placenta had 23.5 times higher phenolic content than seeds. C. chinense and C. chinense × C. frutescens had 3.5 to 5 times higher capsaicinoid content compared to C. annuum and C. baccatum, with 'Carolina Reaper' having the highest content at 7334.3 mg/100 g DW and 'Chilli AS- Rot' the lowest (318.7 mg/100 g DW).

In vitro α-amylase and α-glucosidase enzyme inhibition and antioxidant activity by capsaicin and piperine from Capsicum chinense and Piper nigrum fruits

In the present study, α-amylase and α-glucosidase inhibitory effect and antioxidant activity of capsaicin and piperine from the ethanolic extract of Capsicum chinense (EECch) and Piper nigrum (EEPn) fruits were investigated. Results revealed that EECch exhibited the highest phenolic (154 mg GAE/100 g of tissue) and flavonoid content (75 mg RtE/100 g of tissue) in comparison with EEPn. The predominant compound detected in EECch and EEPn by GC-EIMS analysis was the capsaicin and piperine, respectively. The capsaicin and piperine showed the highest α-amylase and α-glucosidase inhibitory effect and antioxidant activity rather than extracts. The EEPn (IC₅₀= 216 µg/mL) and piperine (IC₅₀= 105 µg/mL) present a highest α-amylase inhibitory effect, while the EECch (IC₅₀= 225 µg/mL) and capsaicin (IC₅₀= 117 µg/mL) showed highest anti-α-glucosidase activity. Molecular docking established that capsaicin and piperine bind at the α-glucosidase and α-amylase through hydrophobic interactions, hydrogen bond, and charge interactions with amino acid residues. The enzyme inhibitory activity and antioxidant properties exhibited by EECch and EEPn could be attributed to the capsaicin and piperine content and other compounds present such as phenolic compounds and flavonoids. These fruits are potential sources of natural antioxidant agents and α-amylase and α-glucosidase inhibitors.

Phenolic Compounds in Mesoamerican Fruits-Characterization, Health Potential and Processing with Innovative Technologies

Diets rich in phenolic compounds have been associated to reducing the risk of metabolic syndrome and its derived disorders. Fruits are healthy components of the human diet because of their vitamin, mineral, fiber and phenolic profile. However, they have a short shelf-life which is limited by microbiological growth and enzymatic activity. Innovative preservation methods such as high hydrostatic pressure, pulsed electric fields, ultrasound, microwave, cold plasma and ultraviolet light have become popular for the processing of fruits because they can preserve nutritional quality. In this review, the phenolic profile and health potential of 38 Mesoamerican fruits were assessed. Phenolic compounds were classified based on their contribution to the diet as flavonoids, phenolic acids, tannin, lignins and stilbenoids. Due to this composition, fruits showed a wide range of bioactivities which included anti-inflammatory, anti-diabetic, anti-hypertensive and anti-obesity activities, among others. Phenolic content in fruits submitted to innovative food processing technologies depended on parameters such as enzymatic activity, antioxidant capacity, microstructure integrity and cell viability. Innovative technologies could increase phenolic content while assuring microbiological safety by (i) promoting the release of bound phenolic compounds during processing and (ii) inducing the synthesis of phenolic compounds by activation of phenylpropanoid pathway during storage.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Foliar Application of Zinc Oxide Nanoparticles and Zinc Sulfate Boosts the Content of Bioactive Compounds in Habanero Peppers

The physiological responses of habanero pepper plants (Capsicum chinense Jacq.) to foliar applications of zinc sulphate and zinc nano-fertilizer were evaluated in greenhouse trials. The effect of the supplement on fruit quality of habanero pepper was particularly observed. Habanero pepper plants were grown to maturity, and during the main stages of phenological development, they were treated with foliar applications of Zn at concentrations of 1000 and 2000 mg L-1 in the form of zinc sulfate (ZnSO4) and zinc oxide nanoparticles (ZnO NPs). Additional Zn was not supplied to the control treatment plants. ZnO NPs at a concentration of 1000 mg L-1 positively affected plant height, stem diameter, and chlorophyll content, and increased fruit yield and biomass accumulation compared to control and ZnSO4 treatments. ZnO NPs at 2000 mg L-1 negatively affected plant growth but significantly increased fruit quality, capsaicin content by 19.3%, dihydrocapsaicin by 10.9%, and Scoville Heat Units by 16.4%. In addition, at 2000 ZnO NPs mg L-1 also increased content of total phenols and total flavonoids (soluble + bound) in fruits (14.50% and 26.9%, respectively), which resulted in higher antioxidant capacity in ABTS (2,2'azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), DPPH (2,2-diphenyl-1-picrylhydrazyl), and FRAP (ferric reducing antioxidant power) (15.4%, 31.8%, and 20.5%, respectively). These results indicate that application of ZnO NPs could be employed in habanero pepper production to improve yield, quality, and nutraceutical properties of fruits.

In silico mining and FISH mapping of a chromosome-specific satellite DNA in Capsicum annuum L

BACKGROUND

A large proportion of eukaryote nuclear genomes is composed of repetitive DNA. Tracing the dynamics of repetitive elements in the genomes of related taxa can reveal important information about their phylogenic relationships as well as traits that have become distinct to a lineage.

OBJECTIVE

Study the genomic abundance and chromosomal location of repetitive DNA in Capsicum annuum L. to understand the repeat dynamics.

METHOD

We quantified repeated DNA content in the C. annuum genome using the RepeatExplorer pipeline.

RESULTS

About 42% of the C. annuum genome dataset comprised repetitive elements. Of these, 0.011, 0.98, 3.09, and 0.024% represented high and low confidence satellite repeats, putative long-terminal repeats (LTRs), and rDNA sequences, respectively. One novel high confidence 167-bp satellite repeat with a genomic proportion of 0.011%, Ca167TR, was identified. Furthermore, FISH with Ca167TR on metaphase chromosomes of C. annuum revealed signals in the subtelomeric regions of the short and long arms of chromosome 3 and 4, respectively.

CONCLUSION

Further understanding of the origin and associated functions of Ca167TR and other repeats in Capsicum will give us insights into the genomic relationships and functions of the genome.

Antioxidative and anti-proliferative potential of Curculigo orchioides Gaertn in oxidative stress induced cytotoxicity: In vitro, ex vivo and in silico studies

Plant phytoconstituents have been a valuable source of clinically important anticancer agents. Antioxidant and anticancerous activity of plant Curculigo orchioides Gaertn were explored In vitro antioxidant activity, antioxidant enzyme activity of oxidatively stressed tissue, and cell culture studies on human cancer cell lines HepG2, HeLa and MCF-7 were carried out. Active plant fractions were subjected to GC-MS analysis and compounds selected on the basis of their abundance were screened in silico with the help of Auto Dock 4.2 tools with pre-selected antioxidant enzymes. Curculigo orchioides Gaertn plant fractions exhibited significant antioxidant activities by virtue of scavenging of free radicals having IC₅₀ value of ethylacetate fraction (EA) for DPPH radical scavenging assay to be 52.93 ± 0.66 μg/ml. Further, antioxidant enzyme defense of mammalian tissue when treated with plant fractions revealed that enzyme concentrations were refurbished which were increased during oxidative stress. MTT assay on cell lines HepG2, HeLa and MCF-7 presented IC₅₀ values of ethylacetate (EA) fraction as 171.23 ± 2.1 μg/ml, 144.80 ± 1.08 μg/ml and 153.51 μg/ml and aqueous ethylacetate (AEA) fraction as 133.44 ± 1.1 μg/ml, 136.50 ± 0.8 μg/ml and 145.09 μg/ml respectively. Further EA and AEA plant fractions down regulated the levels of antiapoptotic Bcl-2 expression and upregulated the expression of apoptotic proteins caspase-3 and caspase-8 through an intrinsic ROS-mediated mitochondrial dysfunction pathway.

KEY MESSAGE

Key findings explained that fractions of Curculigo orchioides Gaertn inhibited oxidative stress by increasing the antioxidant enzyme content and have anticancerous potential on cancer cell lines HepG2, HeLa and MCF-7.

Feeding on ripening and over-ripening fruit: interactions between sugar, ethanol and polyphenol contents in a tropical butterfly

In ripe fruit, energy mostly derives from sugar, while in over-ripe fruit, it also comes from ethanol. Such ripeness differences may alter the fitness benefits associated with frugivory if animals are unable to degrade ethanol when consuming over-ripe fruit. In the tropical butterfly Bicyclus anynana, we found that females consuming isocaloric solutions mimicking ripe (20% sucrose) and over-ripe fruit (10% sucrose, 7% ethanol) of the palm Astrocaryum standleyanum exhibited higher fecundity than females consuming a solution mimicking unripe fruit (10% sucrose). Moreover, relative to butterflies consuming a solution mimicking unripe fruit, survival was enhanced when butterflies consumed a solution mimicking either ripe fruit supplemented with polyphenols (fruit antioxidant compounds) or over-ripe fruit devoid of polyphenols. This suggests that (1) butterflies have evolved tolerance mechanisms to derive the same reproductive benefits from ethanol and sugar, and (2) polyphenols may regulate the allocation of sugar and ethanol to maintenance mechanisms. However, variation in fitness owing to the composition of feeding solutions was not paralleled by corresponding physiological changes (alcohol dehydrogenase activity, oxidative status) in butterflies. The fitness proxies and physiological parameters that we measured therefore appear to reflect distinct biological pathways. Overall, our results highlight that the energy content of fruit primarily affects the fecundity of B. anynana butterflies, while the effects of fruit consumption on survival are more complex and vary depending on ripening stage and polyphenol presence. The actual underlying physiological mechanisms linking fruit ripeness and fitness components remain to be clarified.

Nitrate promotes capsaicin accumulation in Capsicum chinense immobilized placentas

In chili pepper's pods, placental tissue is responsible for the synthesis of capsaicinoids (CAPs), the compounds behind their typical hot flavor or pungency, which are synthesized from phenylalanine and branched amino acids. Placental tissue sections from Habanero peppers (Capsicum chinense Jacq.) were immobilized in a calcium alginate matrix and cultured in vitro, either continuously for 28 days or during two 14-day subculture periods. Immobilized placental tissue remained viable and metabolically active for up to 21 days, indicating its ability to interact with media components. CAPs contents abruptly decreased during the first 7 days in culture, probably due to structural damage to the placenta as revealed by scanning electron microcopy. CAPs levels remained low throughout the entire culture period, even though a slight recovery was noted in subcultured placentas. However, doubling the medium's nitrate content (from 40 to 80 mM) resulted in an important increment, reaching values similar to those of intact pod's placentas. These data suggest that isolated pepper placentas cultured in vitro remain metabolically active and are capable of metabolizing inorganic nitrogen sources, first into amino acids and, then, channeling them to CAP synthesis.