Antioxidant activity and content of chlorophylls and carotenoids in raw and heat-processed Jalapeño peppers at intermediate stages of ripening

Ultrasonication and thermosonication applied in the processing of jalapeno pepper (Capsicum annuum var. annuum) sauce

Ultrasonication is one of the non-thermal physical methods that can be used on foods and when used in synergy with temperature (thermosonication), this technique proves to be more effective, thus reducing the duration and intensity of heat treatment and the consequent damage to the foods. This work aimed to use the technique of ultrasonication and thermosonication in the processing of jalapeno pepper sauces in comparison with pasteurization. Two types of sauces were produced, one with pre-cooking (a) and the other without cooking (b), and the influence of time and temperature was analyzed by applying ultrasonication and thermosonication. Times of 15 and 30 min and temperatures of 25 and 65 °C were used. Both treatments stood out for their effectiveness when compared to the traditional method (pasteurization 65 °C and 30 min). The results demonstrate that, in general, the sauces are good sources of phenolic compounds (141.83 ± 0.10 mg gallic acid equivalent/100 g), flavonoids (50.40 ± 0.30 mg quercetin equivalent/100 g) and carotenoids (2.39 ± 0.07 mg β-carotene/100 g). The sauces had an increase in carotenoids by about 25% (thermosonicated at 15 and 30 min and pre-cooked) and in antioxidant activity (ferric reducing antioxidant power) with about 12% and 13% (thermosonicated at 30 min with and without cooking, respectively) in relation to control (pasteurization). On comparing thermosonication with ultrasound process total phenolics had improved by around 14% and flavonoids by 55%. At the first time, capsantin, capsaicin, dihydrocapsaicin, and nordihydrocapsaicin were identified by ultra-high performance liquid chromatography-MS/MS (UHPLC-MS/MS). Finally, as both treatments demonstrate efficiency (thermosonication at 15 and 30 min), the use of 15 min is indicated as feasible by the reduced process time and in preventing the loss of bioactive compounds in the sauces when compared to the pasteurization treatment.

Changes in Carotenoids and Quality Parameters of Sweet Paprika (Capsicum annuum) After an Accelerated Heat Treatment

Paprika, obtained from dried red pepper (C. annuum), is valued for its characteristic colour and flavour. Its carotenoid content, which is important for both sensory and nutritional quality, varies depending on several factors (agronomic conditions and technological treatment with special attention to the drying methods) that influence the colour and antioxidant capacity of the samples. This study investigated the effect of an accelerated thermal treatment (80 °C for 8 h) applied to evaluate the oxidative stability of the carotenoids and the colour of ground paprika depending on its origin (Peru or China). Changes in quality parameters (ASTA index and CIELAB colour), carotenoid content and profile (HPLC-DAD) and lipophilic antioxidant capacity (FRAP and ABTS•+ methods) were evaluated. Untreated Chinese samples had 30% more total carotenoids than Peruvian samples, but this was not reflected in ASTA units, indicating that at least a 50% carotenoid variation is required for significant differences. Treatment resulted in a carotenoid loss of 70% in Peruvian and 30% in Chinese samples, with changes in total carotenoids correlating positively with antioxidant capacity. Both origins had similar carotenoid profiles, with β-carotene being the predominant carotenoid, while distinct contents were observed between the origins. The higher content of esterified carotenoids in Chinese peppers resulted in better thermal stability. The results highlight the necessity for tailored production processes to maintain nutritional integrity and antioxidant capacity.

Green Ultrasound-Assisted Extraction of Bioactive Compounds from Cumari-Do-Pará Peppers (Capsicum chinense Jacq.) Employing Vegetable Oils as Solvents

Capsaicin, carotenoids, and phenolic compounds from cumari-do-Pará peppers (Capsicum chinense Jacq.) harvested from two different locations in Pará, Brazil, and at different ripening stages were extracted by employing green methodologies as an alternative to organic solvents. Edible vegetable oils from soybeans (Glycine max), Brazilian nuts (Bertholettia excelsa H.B.), and palm olein were used in combination with ultrasonic-assisted extraction (UAE). The proximate composition of the pepper extracts and vitamin C were determined through AOAC methods, total phenolics and carotenoids were assessed by UV/Vis spectrophotometry, and capsaicin by high-performance liquid chromatography. Antioxidant cumari-do-Pará extract activities were evaluated by the ABTS radical scavenging and β-carotene/linoleic acid assays. The vegetable oils were suitable for extracting and preserving bioactive pepper compounds, especially mature ones harvested from Igarapé-Açu. Bioactive compound content and antioxidant activity varied with harvesting location and ripening stage. Soybean oil was the most effective in extracting bioactive pepper compounds, particularly carotenoids, with 69% recovery. Soybean oil extracts enriched in capsaicin, carotenoids, and phenolics obtained from cumari-do-Pará can be used as spices in foodstuffs and/or as additives in pharmaceutical and nutraceutical formulations. Edible vegetable oils combined with UAE are promising for bioactive compound extraction, representing an environmentally friendly, safe, low-cost, versatile, and fast alternative.

Formation of chlorophyll-anionic polysaccharide complex coacervates to improve chlorophyll color stability: Thermodynamic and kinetic stability studies

Chlorophyll (Chl) is the predominant pigment in green plants that can act as a food color and possesses various functional activities. However, its instability and rapid degradation on heating compromise the sensory qualities of its products. This study aimed to enhance the heat resistance of Chl by forming complex coacervates with two negatively charged polysaccharides, sodium alginate (SA) and K-carrageenan (KC). Dynamic light scattering and scanning electron microscopy analyses confirmed the formation of coacervates between Chl and the polysaccharides, whereas Fourier-transform infrared spectroscopy revealed that hydrogen bonding and electrostatic attraction were the primary forces behind complex formation. Electron spin resonance and thermodynamic studies further revealed that these complexes bolstered the thermal stability of Chl, with a maximum improvement of 70.38 % in t1/2 and a reduction of 50.72 % in the degradation rate constant. In addition, the antioxidant capacity of Chl was enhanced up to 35 %. Therefore, this study offers a novel approach to Chl preservation and suggests a viable alternative to artificial pigments in food products.

Cloning and Analysis of Expression of Genes Related to Carotenoid Metabolism in Different Fruit Color Mutants of Pepper (Capsicum annuum L.)

The formation of fruit color in pepper is closely related to the processes of carotenoid metabolism. In this study, red wild-type pepper XHB, SP01, PC01 and their corresponding mutants H0809 (orange), SP02 (yellow), and PC02 (orange) were used as research materials. The Ggps, Psy, Lcyb, Crtz, Zep, and Ccs genes involved in carotenoid biosynthesis were cloned, and bioinformatics and expression analyses were carried out. The results showed that the full lengths of the six genes were 1110 bp, 2844 bp, 1497 bp, 2025 bp, 510 bp, and 1497 bp, and they encoded 369, 419, 498, 315, 169, and 498 amino acids, respectively. Except for the full-length Ccs gene, which could not be amplified in the yellow mutant SP02 and the orange mutant PC02, the complete full-length sequences of the other genes could be amplified in different materials, indicating that the formation of fruit color in the SP02 and PC02 mutants could be closely related to the deletion or mutation of the Ccs gene. The analytical results of real-time quantitative reverse transcription PCR (qRT-PCR) showed that the Ggps, Psy, Lcyb, Crtz, and Zep genes were expressed at different developmental stages of three pairs of mature-fruit-colored materials, but their patterns of expression were not consistent. The orange mutant H0809 could be amplified to the full Ccs gene sequence, but its expression was maintained at a lower level. It showed a significant difference in expression compared with the wild-type XHB, indicating that the formation of orange mutant H0809 fruit color could be closely related to the different regulatory pattern of Ccs expression. The results provide a theoretical basis for in-depth understanding of the molecular regulatory mechanism of the formation of color in pepper fruit.

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.

The Vacuum and Light-Avoided Packaging Ameliorate the Decline in Quality of Whole Chili during Storage

Vacuum packaging is a superior procedure that could maintain the quality of dried red peppers for a relatively longer period, while the effect of light avoidance was inconsistent. Therefore, this study was to evaluate the effect of vacuum in combination with light avoidance on the storage quality of peppers and to investigate vacuum packaging and vacuum and light-avoided packaging influence the quality characteristics of dried chili peppers during storage. The results indicated that the quality characteristics of peppers gradually deteriorated: redness, extractable color, capsanthin, capsaicinoids, pungency, total phenolic content, and antioxidant capacity decreased, whereas moisture, water activity, and browning index increased as storage progressed. Vacuum packaging inhibited these changes compared with the control. Vacuum and light-avoided packaging further decelerated the quality loss of dried peppers, with the minimum changes in color, pungency, and antioxidant capacity of dried peppers during storage, and these could be due to lower water activity by light avoidance. Therefore, light avoidance may be necessary to further delay the deterioration of dried peppers under vacuum, and vacuum and light-avoided packaging could better retain the quality of dried chili peppers.

Effects of Different Zn2+ Concentrations and High Hydrostatic Pressures (HHP) on Chlorophyll Stability

This study provides a new idea for improving chlorophyll stability and color quality of green leafy vegetables by Zn2+ synergistic HHP. Zn-chlorophyll was prepared with zinc acetate and chlorophyll under HHP treatment. The effects of different zinc acetate concentrations and pressures on chlorophyll color, antioxidant activity, Zn2+ replacement rate, structure, and thermal stability were analyzed. Results showed with increased zinc acetate concentration and pressure, −a* value, antioxidant activity, and Zn2+ replacement rate of samples gradually increased. However, FTIR indicated the structure did not change. HHP fluorescence online analysis showed fluorescence intensity of samples decreased with zinc acetate concentration and pressure increasing. With zinc acetate 10 mg/100 mL and HHP 500 MPa, the highest −a* value (5.19), antioxidant activity (ABTS, DPPH, and FRAP were 37.03 g ACE/100 g, 25.95 g ACE/100 g, 65.43 g TE/100 g DW, respectively), and Zn2+ replacement rate (42.34%) were obtained. Thermal stability of Zn-chlorophyll obtained by synergistic effect was improved significantly.

The physicochemical properties and the release of sodium caseinate/ polysaccharide gum chlorophyll multiple-layer particles by rotary side-spray fluid bed technology

Multiple-layer coating technology has widely applied to the quality modification of bioactive ingredients nowadays. This research used a rotary side-spray fluid bed to manufacture chlorophyll multiple-layer particles to adjust control release characteristics. The chlorophyll extracts were coated with sodium alginate (A1) and sodium caseinate (CA1) as the primary layer on sugar spheres and the product yield was 96.98 and 96.71%, respectively. The content of chlorophyll a and b (μg/g) were 41.04 and 13.20 in A1, 47.40 and 13.68 in CA1. The Fourier-transform infrared spectroscopy confirmed the bonding change and increase stability. The CA1 was coated with sodium alginate (CA-A), sodium carboxymethylcellulose (CA-C) and xanthan gum (CA-X) as the secondary layer, which can increase coated integrity, shell strength and thermal stability. The simulated gastrointestinal fluid showed 30.11% release in the stomach and 94.27% in the intestine, which improved release control characteristics. Increased retention rate and color stability in the storage test.

Anthocyanins and Carotenoids Characterization in Flowers and Leaves of Cyclamen Genotypes Linked with Bioactivities Using Multivariate Analysis Techniques

The present study was carried out to evaluate and compare in vitro antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP)), antimicrobial, anticancer activities, and the individual carotenoids and anthocyanins content of methanol extracts of the Cyclamen genotypes: Persian cyclamen accessions (Cyclamen persicum Mill.), sowbread (C. mirabile Hildebr.), and ivy-leaved cyclamen (C. hederifolium Mill.) aerial parts. The HPLC-PDA analysis revealed the presence of five individual carotenoids (i.e., neoxanthin, violaxanthin, lutein, β-carotene, and cis-β-carotene) as the main compounds in Cyclamen leaves, and the presence of seven individual anthocycanins (i.e., cyanidin 3,5-di-O-glucoside, peonidin-rutinoside, peonidin 3,5-di-O-glucoside, peonidin 3-O-glucoside, malvidin 3-O-glucoside, malvidin 3,5-di-O-glucoside, and malvidin-rutinoside) in Cyclamen flowers reported, hereby, for the first time. The highest phenolic content was found in the leaves of LC6, C. mirabile (46.32 ± 0.14 mg/g gallic acid equivalents [GAE]), and in the flowers of C. persicum Merengue Magenta (FC15) (58.63 ± 0.17 mg/g GAE), whereas the highest flavonoid content was reported in C. persicum Halios Falbala leaves, namely LC9 (54.90 ± 0.27 mg/g quercetin equivalents [QE]) and in flowers of C. persicum Victora (FC2) (77.87 ± 0.25 mg/g QE). The highest antioxidant activity in DPPH and FRAP assays was reported in C. persicum Dark Violet (LC1) and Victoria (LC2), whereas C. mirabile (LC6) had the highest activity in the TEAC assay. In flowers, high antioxidant activities in DPPH and TEAC were noticed in C. persicum Superserie Red (FC7) and Dark Violet (FC1), respectively, and Halios Falbala (FC9) exhibited the highest activity in the TEAC assay. Additionally, FC9 exhibited the highest antibacterial activity in almost all tested bacteria compared with the leaves extracts. Furthermore, the highest in vitro citotoxicity in MDA-MB-231 cells was noticed in C. hederifolium LC18 (56.71-69.35%) and FC18 (40.07-41.43%), with a lower effect against BJ cells demonstrating selective toxicity. The above findings, highlight the potential use of the Cyclamen flower and leaf extracts as significant anticancer agents along with their antioxidant and antimicrobial properties.

Pilot-Scale Optimization of Supercritical CO2 Extraction of Dry Paprika Capsicum annuum: Influence of Operational Conditions and Storage on Extract Composition

Supercritical carbon dioxide extraction was used to extract carotenoids from dry paprika Capsicum annuum. Studies regarding the effect of process parameters, including pressure (25–45 MPa), temperature (40–60 °C), and time (10–110 min), were carried out using response surface methodology. It was found that under optimal conditions (pressure of 45 MPa, temperature of 50 °C, and time of 74 min), the extract yield was 10.05%, and the total content of carotenoids in the extract was 4.21%, in good agreement with the predicted values (10.24% and 4.24%, respectively). Composition analysis showed that paprika extract mainly consisted of linoleic acid. There was no significant difference between the fatty acid content of the extracts obtained by SC-CO₂ extraction and n-hexane Soxhlet extraction. For functional purposes, the effect of storage conditions and time on the quality of paprika extract was also specified.

Identification of Phenolic Compounds in Australian-Grown Bell Peppers by Liquid Chromatography Coupled with Electrospray Ionization-Quadrupole-Time-of-Flight-Mass Spectrometry and Estimation of Their Antioxidant Potential

Bell peppers are widely considered as healthy foods that can provide people with various phytochemicals, especially phenolic compounds, which contribute to the antioxidant property of bell peppers. Nevertheless, the acknowledgment of phenolic compounds in bell peppers is still limited. Therefore, this study aimed to determine the phenolic content and the antioxidant potential in pulps and seeds of different bell peppers (green, yellow, and red) by several in vitro assays followed by the characterization and quantification of individual phenolics using liquid chromatography coupled with electrospray ionization-quadrupole-time-of-flight-mass spectrometry (LC-ESI-QTOF-MS/MS) and high-performance liquid chromatography photodiode array (HPLC-PDA) quantification, respectively. The captured results showed that the pulp of red bell peppers exhibited the highest phenolic content in the total polyphenol content (1.03 ± 0.07 mg GAE/gf.w.), total flavonoid content (137.43 ± 6.35 μg QE/gf.w.), and total tannin content (0.22 ± 0.01 mg CE/gf.w.) as well as the most antioxidant potential in all antioxidant capacity estimation assays including total antioxidant capacity (3.56 ± 0.01 mg AAE/gf.w.), 2,2'-diphenyl-1-picrylhydrazyl (0.89 ± 0.01 mg AAE/gf.w.), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (1.36 ± 0.12 mg AAE/gf.w.), and ferric reducing antioxidant power (0.15 ± 0.01 mg AAE/gf.w.). LC-ESI-QTOF-MS/MS isolated and identified a total of 59 phenolic compounds, including flavonoids (21), phenolic acids (20), other phenolic compounds (12), lignans (5), and stilbenes (1) in all samples. According to HPLC-PDA quantification, the seed portions showed a significantly higher amount of phenolic compounds. These findings indicated that the waste of bell peppers can be a potential source of phenolic compounds, which can be utilized as antioxidant ingredients in foods and nutritional products.

Effect of different genotypes on the fruit volatile profiles, flavonoid composition and antioxidant activities of chilli peppers

The main purpose of the present study was toinvestigate the influence of genotypes on the volatile, flavonoid-related compounds and antioxidant capacities of chilli peppers. A set of 49 volatiles were identified in the chilli peppers using gas chromatography-ion mobility spectrometry (GC-IMS). The flavonoid-related profiles were established by the simultaneous LC-MS measurement of 38 compounds. The results of chemometrics analysis reveal that Jize and Korean chilli peppers can be distinctly separated from each other. A panel of 18 volatile and 13 flavonoid-related variables with VIP > 1 and p < 0.05 were determined as the discriminants for Jize and Korean chilli peppers. Moreover, Korean chilli peppers showed significantly (p < 0.05) higher antioxidant activity than Jize chilli peppers. A clear and positive correlation was observed between the antioxidant potential and individual flavonoid compounds. The current findings could facilitate the valorization of chilli peppers as bioactive and functional ingredients at various commercial levels.

Preparation and evaluation of oral self-microemulsifying drug delivery system of Chlorophyll

OBJECTIVE

This study was aimed at improving the water solubility and oral bioavailability of Chl by self-microemulsifying drug delivery system (Chl-SMEDDS).

METHODS

Compatibility experiments, pseudo-ternary phase diagram and central composite design were used to optimize the formulation. The selected systems were further evaluated for physical characteristics, including particle size, zeta potential, and appearance. The stability, in vitro dispersion test, and in vivo intestinal perfusion experiments were used to evaluate the SMEDDS.

RESULTS

The optimal composition of Chl-SMEDDS included: Labrafil M 1944 CS (35%), kolliphor RH 40 (46%), Transcutol HP (19%) and 60 mg/g Chl. The appearance of water emulsified Chl-SMEDDS was green and transparent. The particle size, ζ-potential, and transmission electron microscopy studies showed that spherical globules of Chl-SMEDDS with a size of about 22.82 ± 1.29 nm and a negative surface charge of -24.21 ± 3.45 mV were obtained. Chl-SMEDDS could remain stable at 25 °C and 4 °C for at least 6 months. The dispersion test showed that Chl-SMEDDS dispersed spontaneously to form microemulsion after disintegration of capsule shell and 90% drug dispersed in just 30 min in pH 1.2 HCl without any drug precipitation during the test period. In vivo intestinal perfusion experiment revealed that the main absorption site for Chl-SMEDDS was duodenum.

CONCLUSIONS

This study indicates that SMEDDS formulation could be an effective strategy for the oral administration of Chl.

Understanding colour retention in red chilli pepper fruit using a metabolite profiling approach

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Image analysis can be used to speed up identification of high retention phenotypes.

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High and low retention phenotypes can be identified by their volatomes.

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Low retention lines have increased unsaturated fatty acids.

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Post-harvest colour loss in chilli fruit involves lipid peroxidation.

Carotenoids are the pigments responsible for conferring the characteristic deep red colour to chilli pepper. The post-harvest retention of this colour is a key trait that governs the price of the produce. Determining colour retention and the associated underlying biochemical mechanisms are important issues that require investigation. In this present study, the ability of image analysis to determine colour change in ground chilli fruit was evaluated. This method enabled differentiation of extreme retention phenotypes whilst also reducing the duration of storage required to make accurate determinations. The analysis of volatiles indicated different levels of lipid and carotenoid derived volatiles in lines with different retention properties. Metabolite profiling of intermediary metabolism supported these findings, with increased levels of unsaturated fatty acids present in lines with low retention properties. Collectively, these data have led us to propose that in chilli fruit lipid peroxidation is one of the progenitors of carotenoid degradation.

Effects of Linseed Meal and Carotenoids from Different Sources on Egg Characteristics, Yolk Fatty Acid and Carotenoid Profile and Lipid Peroxidation

The present study aimed to evaluate the effect of supplementing the diet of laying hens with linseed meal and carotenoids from different sources on egg characteristics, yolk fatty acid and carotenoid profile, and lipid peroxidation. A 4-week experiment was conducted on 168 Lohmann Brown layers (43 weeks of age), assigned to four dietary treatments (42 hens/group; 21 replicate/groups with 2 birds/pen) consisting of a control diet (C) and three diets simultaneously supplemented with 6% linseed meal and 2% dried kapia pepper (E1), 2% dried sea buckthorn pomace (E2) and 2% dried carrot (E3). Every 2 weeks, 18 eggs/group/period were collected randomly from each group and used to determine the egg quality and nutritional parameters. The results showed that dietary linseed meal and carotenoids sources improved egg color, carotenoids’ accumulation in egg yolk and fatty acid profile, especially the n-3 PUFA content. Dietary carotenoids supplementation reduced, n-6/n-3 ratio, cholesterol content of the egg yolk and improved yolk pH, egg thickness and yolk oxidative stability. In conclusion, the use of these sources of carotenoids in the linseed meal enriched diets could be an effective way to improve the nutritional properties of the eggs without affecting their quality and consumer’s safety.

Occurrence and Determination of Carotenoids and Polyphenols in Different Paprika Powders from Organic and Conventional Production

Paprika powder is a good source of different carotenoids and polyphenols, which play a key role in preventing certain diseases (some kinds of cancer and cardiovascular diseases). They can also be used as natural food colorants. Organic production is characterized by strict rules, but products obtained in this way contain more bioactive compounds, such as carotenoids and polyphenols. The aim of this study was to measure and identify carotenoids and polyphenols in different paprika samples (sweet, hot, smoked, and chili) obtained by organic and conventional production. Quantitative and qualitative carotenoid and polyphenols analysis showed that the experimental samples contained different concentrations of these compounds.

Structural and functional features of phytoene synthase isoforms PSY1 and PSY2 in pepper Capsicum annuum L. cultivars

The fruits of various pepper cultivars are characterized by a different color, which is determined by the pigment ratio; carotenoids dominate in ripe fruits, while chlorophylls, in immature fruits. A key regulator of carotenoid biosynthesis is the phytoene synthase encoded by the PSY gene. The Capsicum annuum genome contains two isoforms of this enzyme, localized in leaf (PSY2) and fruit (PSY1) plastids. In this work, the complete PSY1 and PSY2 genes were identified in nine C. annuum cultivars, which differ in ripe fruit color. PSY1 and PSY2 sequence variability was 2.43 % (69 SNPs) and 1.21 % (36 SNPs). The most variable were PSY1 proteins of the cultivars 'Maria' (red-fruited) and 'Sladkij shokolad' (red-brown-fruited). All identified PSY1 and PSY2 homologs contained the phytoene synthase domain HH-IPPS and the transit peptide. In the PSY1 and PSY2 HH-IPPS domains, functionally significant sites were determined. For all accessions studied, the active sites (YAKTF and RAYV), aspartate-rich substrate-Mg²⁺-binding sites (DELVD and DVGED), and other functional residues were shown to be conserved. Transit peptides were more variable, and their similarity in the PSY1 and PSY2 proteins did not exceed 78.68 %. According to the biochemical data obtained, the largest amounts of chlorophylls and carotenoids across the cultivars studied were detected in immature and ripe fruits of the cv. 'Sladkij shokolad' and 'Shokoladnyj'. Also, ripe fruits of the cv. 'Nesozrevayuschij' (green-fruited) were marked by significant chlorophyll content, but a minimum of carotenoids. The PSY1 and PSY2 expression patterns were determined in the fruit pericarp at three ripening stages in 'Zheltyj buket', 'Sladkij shokolad', 'Karmin' and 'Nesozrevayuschij', which have different ripe fruit colors: yellow, red-brown, dark red and green, respectively. In the leaves of the cultivars studied, PSY1 expression levels varied significantly. All cultivars were characterized by increased PSY1 transcription as the fruit ripened; the maximum transcription level was found in the ripe fruit of 'Sladkij shokolad', and the lowest, in 'Nesozrevayuschij'. PSY2 transcripts were detected not only in the leaves and immature fruits, but also in ripe fruits. Assessment of a possible correlation of PSY1 and PSY2 transcription with carotenoid and chlorophyll content revealed a direct relationship between PSY1 expression level and carotenoid pigmentation during fruit ripening. It has been suggested that the absence of a typical pericarp pigmentation pattern in 'Nesozrevayuschij' may be associated with impaired chromoplast formation.

Bioaccessibility of fat-soluble bioactive compounds (FSBC) from avocado fruit as affected by ripening and FSBC composition in the food matrix

Dried fruit pulp and oil from avocado fruit (Persea americana, Cv Hass) at five different ripening stages were digested in vitro to determine the bioaccessibility of several fat-soluble bioactive compounds (FSBC). Viscosity, particle size, ζ-potential and lipolysis were evaluated and related to the bioaccessibility of the tested compounds. Fatty acids were more bioaccessible than carotenoids and tocopherols. The viscosity of gastrointestinal medium was related to the initial fruit firmness and modulated the bioaccessibility of neoxanthin, violaxanthin, lutein and luteoxanthin, while particle size and ζ-potential influenced the bioaccessibility of fatty acids. Lipolysis degree highly altered the bioaccessibility of luteoxanthin, pheophytin b, and α-tocopherol indicating that these digestive events are highly involved in the bioaccessibility of FSBC. In summary, FSBC from avocado fruit are highly bioaccessible, but their bioaccessibility depends on fruit ripening stage and FSBC type and concentration.

The effects of production methods on the color characteristics, capsaicinoid content and antioxidant capacity of pepper spices (C. annuum L.)

The effects of production methods for red pepper flakes (RPF) and traditional (TRI) and industrial (INI) isot spices were evaluated with respect to the carotenoid and capsaicinoid contents, extractable color (ASTA color), surface color parameters, nonenzymatic browning (NEB), and the DPPH free radical-scavenging capacity of fresh red Capsicum (FRC). The measured characteristics were significantly affected by the processing methods used. RPF exhibited the highest antioxidant activity and best color quality in terms of carotenoid content, which was the highest; ASTA value; surface color intensity; and NEB, which was the lowest. In contrast, INI-processing methods resulted in poor color quality, causing the maximum increase in NEB. The concentration of capsaicinoid increased at the end of TRI processing, whereas it decreased in the two other methods. These results suggest that the traditional production method for isots prevents excessive destruction of their color attributes and contributes to the desirable characteristic browning.

Comparison of blue discoloration in radish root among different varieties and blue pigment stability analysis

The internal blue discoloration of radish root after harvest is a physiological phenomenon that decreases the radish quality. Internal blue discoloration in the roots of 16 varieties of Chinese radish along with the stability of blue pigment under different light, pH, and temperature conditions were investigated. Among the varieties LB05-244 and LB05-240 displayed the greatest degrees of discoloration, while the Piton and Dense radishes exhibited the lowest degrees of discoloration. The light and pH conditions along with the storage temperature affected the pigment stability. The degradation of blue pigment occurred faster under blue light than under green, red, and white light and darkness. Blue pigment degraded fastest at pH values of 13 and 1. The blue pigments in radish exhibited thermal instability, with complete degradation occurring in 5 or 10 min at 90 or 100 °C, respectively. In conclusion, variety affected the discoloration. The pigment exhibited light, pH and thermal instability.

Red bell pepper (Capsicum annuum L.): Optimization of drying conditions and preparation of functional bread

The aim of this study was to optimize the drying conditions (pretreatments and drying temperatures) of red bell pepper to obtain red bell pepper powder (RBP) with maximum bioactive retention and assess its potential use as a functional ingredient in bread. The RBP pretreated (blanching + dipping in ascorbic and citric acid solution) and dried at 60 °C retained the highest bioactive compounds. Wheat flour blends were prepared with RBP at 0%, 2%, 4%, 6%, 8%, and 10% level of incorporation and among hydration properties, water absorption increased with increasing levels. The prepared breads were assayed for physical, nutritional, bioactive, and sensory characteristics. Bread supplementation with RBP improves its color, mineral, fiber, and bioactive properties. However, the texture of bread becomes hard with the increased level of RBP due to a decrease in specific volume. The significant increment was recorded for bioactive compounds, such as total phenols, antioxidant activity, flavonoids, and carotenoids as the level of powder increased. Bread enriched with 6% RBP showed highest sensory scores (8.45) and index of acceptability (87.83%) as compared to other breads. Thus, RBP acts as a valuable supplement for developing bread with improved nutritional and bioactive constituents. PRACTICAL APPLICATION: This study describes the effect of different pretreatments and drying temperatures for processing of RBP as a functional ingredient in bread, being a staple food around the world. RBP powder is a novel ingredient that improved the nutritional, bioactive, and appearance of bread. Hence, it will be helpful in the utilization of perishable crops like bell pepper and will demonstrate its commercial viability to improve the nutritive value of bakery products.

Physico-Chemical Characterization of Tunisian Canary Palm (Phoenix canariensis Hort. Ex Chabaud) Dates and Evaluation of Their Addition in Biscuits

Phoenix canariensis Hort. Ex Chabaud, also known as the Canary Island palm or ornamental palm, is an endemic species of the Canary Islands and has been widely propagated globally. It has become one of the most important and appreciated ornamental plants, especially in the Mediterranean climate. The fruits are edible but used only for feed as they are bitter. Despite its diffusion, not much data on the composition of these fruits and their application as food are available. The aim of this study was to define the chemical characteristics, especially those of the polyphenolic constituents, of red and yellow varieties of Canary palm dates, and to evaluate their use alone or in different mixes in biscuit production. The yellow variety had higher quantities of fiber (36.88% DW (Dry Weight)) and polyphenolic compounds, while the red variety had a high content of sugars, mainly glucose (22.8% DW). Epicatechin is the most important polyphenol of dates (562 μg/g DW). The use of date palm powder on biscuit production resulted in an increase in hardness, polyphenol and fiber content, and antioxidant activity. Sensory analysis showed that the biscuits obtained with a 25/75 mix of red/yellow date powder had the most overall liking.

Influence of Postharvest Temperatures on Carotenoid Biosynthesis and Phytochemicals in Mature Green Chili (Capsicum annuum L.)

An intense red color appearance in hot chili is what industry commonly demands. The harvested mature green “Takanotsume” chili, a popular cultivar in Japan, incubated at 20 and 30 °C is investigated. At 30 °C, the chili rapidly degraded chlorophylls and obtained an intense red color, but presented an orange–red color at 20 °C. The sample showed higher carotenoid accumulations at 30 °C, along with significantly upregulated carotenoid biosynthesis-related genes—phytoene synthase (Psy), lycopene-β-cyclase (Lcyb), β-carotene hydroxylase (CrtZ), and capsanthin/capsorubin synthase (Ccs)—during the experiment. While the expression of the Ccs gene was reduced, there was a 5.5-fold upregulation of the Psy gene at the end of incubation. At 20 °C, the Psy gene was downregulated. These observations suggest that the expression of individual genes is temperature-dependent, and these would affect specific carotenoid compounds. The antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl; DPPH and ferric-reducing antioxidant power; FRAP) values had no difference between temperatures; the higher content of total phenolics and vitamin C presented in the chili at 30 °C probably corresponds to the advanced ripening process. Thus, 30 °C is the recommended incubation temperature for mature green chili to achieve the industry-demanded intense red color and high accumulation of phytochemicals.

Color Development and Phytochemical Changes in Mature Green Chili (Capsicum annuum L.) Exposed to Red and Blue Light-Emitting Diodes

Exposure of mature green "Takanotsume" chili fruit to blue and red light-emitting diodes (LEDs) was investigated. The red LED accelerated the red color development of chili as indicated by higher a* and chroma values, as well as lower hue angle and total chlorophyll compared to the blue LED and darkness (control). These were linked to increases in β-carotene, free-capsanthin, and total carotenoids. The carotenoid biosynthesis-related genes, lycopene-β-cyclase (Lcyb), β-carotene hydroxylase (CrtZ), and capsanthin/capsolubin synthase (Ccs), were up-regulated by the red LED after 2 days of the experiment. The blue LED was more effective in increasing the expression of the phytoene synthase (Psy) gene at day 1 of experiment. The total phenolic, vitamin C content, and antioxidant capacity were also higher in the blue LED-treated chili. Results suggest that the responses of each carotenoid-related gene to the light wavelengths and the accumulation of phytochemicals are specific characteristics of this chili cultivar.

Carotenoids of Capsicum Fruits: Pigment Profile and Health-Promoting Functional Attributes

Pepper of the Capsicum species is a common ingredient in various food preparations by different cultures worldwide. The Capsicum is recognised by its five main domesticated species, namely Capsicum annuum, C. baccatum, C. chinense, C. frutescens and C. pubescens. The genetic diversity in Capsicum offers fruits in wide ranges of morphology and carotenoid profile. Carotenoids enhance the value of pepper from a nutritional standpoint, despite being commonly prized for the pharmacologically active pungent capsaicinoids. Carotenoids of pepper comprise mainly of the unique, powerful and highly stable capsanthin and capsoroubin, together with β-carotene, β-cryptoxanthin, lutein, zeaxanthin, antheraxanthin and violaxanthin. These carotenoids are present at diverse profile and varying levels, biosynthetically connected to the fruit maturity stages. This review describes the health-promoting functional attributes of the carotenoids that are mainly associated with their excellent role as lipophilic antioxidants. Capsicum as a great source of carotenoids is discussed in the aspects of main domesticated species, biosynthesis, pigment profile, antioxidant activity and safety. Findings from a number of in vitro, in vivo and clinical studies provided appreciable evidence on the protective effects of pepper’s carotenoids against degenerative diseases. Hence, pepper with its functional carotenoids might be recommended in health-promoting and disease preventing strategies.

Carotenoid biosynthesis and sequestration in red chilli pepper fruit and its impact on colour intensity traits

The exploitation of diverse natural variation has been a key progenitor of crop breeding over the last decade. However, commercial practice is now turning to the use of accessions with less extreme phenotypes as genetic donors. In the present study, the carotenoid formation in a red-fruited discovery panel of Capsicum annuum (chilli pepper) has been characterized. The data indicated that colour intensity correlated with the amount of capsanthin and its esters, along with transcript levels of the 1-deoxy-d-xylulose 5-phosphate synthase (DXS) and phytoene synthase-1 (PSY-1) genes. Quantification of carotenoids through development and ripening suggested the presence of separate biosynthesis and accumulation phases. Subplastid fractionation demonstrated the differential sequestration of pigments in high- and low-intensity lines and revealed the PSY protein to be most active in the membrane fractions when abundance was highest in the fibril fractions. Carotenoid accumulation was associated with the esterification of xanthophylls, expression of a putative carotenoid acyl transferase, and increased fibril content within the plastid. Interrogation of TEM images and carotenoid analysis of subplastid fractions suggest that the plastoglobuli are likely to be the progenitor of the characteristic fibrils found in pepper fruit. Collectively, these data provide an insight into the underpinning molecular, biochemical, and cellular mechanisms associated with the synthesis and sequestration of carotenoids in chromoplast-containing fruits, in addition to providing potential tools and resources for the breeding of high red colour intensity pepper varieties.

Influence of roasting on chemical profile, antioxidant and antibacterial activities of dried chili

Roasted dried chili, used to improve texture and taste, is important for various cuisines. The effect of roasting at 90 °C for 25 min on the chemical profile and bioactivities of dried chili extracted by petroleum ether was investigated. Based on GC-MS analysis, the crude extracts of roasted dried chili exhibited different chemical profile compared to the control. Roasting of dried chili significantly increased total phenolic compounds. Consequently, the antioxidant activity indicated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP) significantly improved. Conversely, a reduction in the antibacterial agents, capsaicin (32.36%) and dihydrocapsaicin (9.11%), in the roasted sample resulted to a decline in antibacterial activity. The extracts showed a strong activity against Bacillus cereus followed by B. subtilis, and Staphylococcus aureus compared to Escherichia coli based on the results of agar disk diffusion, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), and electron scanning microscopy observation.

Diversity in Accessions of Panicum miliaceum L. Based on Agro-Morphological, Antioxidative, and Genetic Traits

The genetic diversity and antioxidant potential of Panicum miliaceum L. accessions collected from different geo-ecological regions of South Korea were evaluated and compared. Antioxidant potential of seeds was estimated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical scavenging assays and total phenolic content was determined by the Folin–Ciocalteu method. Total phenolic content (TPC) in 80% methanolic extracts ranged from 16.24 ± 0.86 to 58.04 ± 1.00 mg gallic acid equivalent (GAE)/g of the sample extracts and total flavonoid content (TFC) varied from 7.19 ± 1.05 to 52.56 ± 1.50 mg quercetin equivalents (QE) mg/g of the sample extracts. DPPH radical scavenging capacity of the extracts from the 15 accessions of P. miliaceum varied from 206.44 ± 7.72 to 2490.24 ± 4.641 mg GAE/g of the sample extracts and ABTS radical scavenging capacity ranged from 624.85 ± 13.1 to 1087. 77 ± 9.58 mg GAE/g of the sample extracts. A wide range of genetic variation was observed as measured by Shannon’s information index (I), number of effective alleles (Ne), number of observed alleles (Na), expected heterozygosity (He), unbiased expected heterozygosity (uHe). The observed variation in the bioactive properties, morphological traits, and genetic diversity among the accessions may provide useful information for breeding programs seeking to improve bioactive properties of P. miliaceum.

Impact of steam treatment on shelf-life stability of a xanthone-rich green herbal tea (Cyclopia maculata Andrews Kies) - identifying quality changes during storage

BACKGROUND

Steam treatment of shredded, fresh C. maculata (honeybush) plant material improves the aroma of this green herbal tea with a slight impact on color and phenolic content, but the effect on storage stability is not known.

RESULTS

Steam-treated (60 s before drying) and untreated (control) dried plant material was stored under normal storage conditions in semi-permeable sachets at 25 °C and 60% relative humidity. Reference samples of treated (steamed) and untreated (control) material were stored at 0 °C in impermeable pouches for maximum retention of quality. The stability of the herbal tea was assessed in terms of sensory profile, phenolic composition and color over a storage period of 6 months. Normal storage conditions resulted in a significant (P < 0.05) decrease in green color, especially in steamed samples. Intensities of fruity and sweet-associated aroma attributes increased progressively during storage, while the opposite was observed for vegetal and cereal-like attributes. These changes in the aroma profile were more pronounced in untreated (control) samples. Individual phenolic content remained stable during storage.

CONCLUSIONS

Storage of 3 to 6 months may result in a more appealing aroma profile and enhanced product quality, despite loss of green color. © 2018 Society of Chemical Industry.

The genus Capsicum: a phytochemical review of bioactive secondary metabolites

The Capsicum genus is one of the most popular plants consumed and cultivated worldwide, containing approximately 50 000 varieties of pepper. Due to its wide biodiversity, the chemical composition within the genus also presents a great variability. Its major applications are in food and pharmacological industry, as pepper presents a chemical composition rich in capsaicinoids, carotenoids, flavonoids and volatile compounds which is attributed to the ability of the fruit to remove insipidity, produce aromas and act against oxidative diseases. Due the existence of several cultivars there is a huge intraspecific chemical variability within each species, which can be considered as an obstacle when selecting and cultivating a species to be applied as a natural product source for a specific objective. The usage of pepper-based products in different industrial areas requires pre-established ranges of chemical compounds, such as capsaicinoids, which in high concentration are toxic when consumed by humans. Applying a pepper with a chemical profile closely related to the concentration that is required after industrial processing can improve efficacy and effectiveness of the process. An insight into the chemical characteristics of major secondary bioactive compounds within Capsicum, the factors that affect their concentration and their chemosystematic implication are reported and discussed.