Composition of Main Carotenoids in Korean Red Pepper (Capsicum annuum, L) and Changes of Pigment Stability During the Drying and Storage Process

Effects of packaging and temperature abuse on the quality of red pepper (Capsicum annuum L.) powder

Storage stability of pepper (Capsicum annuum L.) powder packaged using 2 different film pouches of Ny/PE and PET/Al/PE inserted with moisture absorbent and oxygen scavenger was investigated during storage at 25 °C for 5 months and at 40 °C for 14 days. The moisture content of red pepper powder did not change significantly in PET/Al/PE packaging but decreased significantly in Ny/PE packaging after the abuse of storage temperature. The color of red pepper powder was quite stable in all packaging treatments. Other quality characteristics of all packaged pepper powder, including microbial cell count, capsaicinoids, ascorbic acid, and free sugar content, were also maintained near their initial levels with no appreciable changes during storage. Red pepper powder with a moisture content of 13-14% and packaged with a film with high gas-barrier properties can be stored for more than 5 months even if there is an unexpected temperature abuse during storage.

Post-Harvest Red- and Far-Red-Light Irradiation and Low Temperature Induce the Accumulation of Carotenoids, Capsaicinoids, and Ascorbic Acid in Capsicum annuum L. Green Pepper Fruit

Environmental factors, such as light of different spectral compositions and temperature, can change the level of activated photoreceptors which, in turn, can affect the biosynthesis of secondary metabolites in the cells of green fruit. By briefly irradiating the harvested fruit of Capsicum annuum L. hot peppers with red light (RL, maximum 660 nm) and far-red light (FRL, maximum 730 nm) and by keeping them at a low temperature, we attempted to determine whether the state of phytochromes in fruit affects the biosynthesis of secondary metabolites. Using HPLC, we analysed the qualitative composition and quantitative content of the main carotenoids and alkaloids and the chlorophylls and ascorbate, in pepper fruit exposed to the above factors. We measured the parameters characterising the primary photochemical processes of photosynthesis and the transcript levels of genes encoding capsaicin biosynthesis enzymes. The total carotenoids content in the fruit increased most noticeably after 24 h of RL irradiation (more than 3.5 times compared to the initial value), and the most significant change in the composition of carotenoids occurred when the fruit was irradiated with FRL for 72 h. The capsaicin alkaloid content increased markedly after 72 h of FRL irradiation (more than 8 times compared to the initial value). It was suggested that decrease in the activity of phytochromes due to a low temperature or FRL may result in an increase in the expression of the PAL and CAM genes.

A Comprehensive Review of Pesticide Residues in Peppers

Pesticides are chemicals that are used to control pests such as insects, fungi, and weeds. Pesticide residues can remain on crops after application. Peppers are popular and versatile foods that are valued for their flavor, nutrition, and medicinal properties. The consumption of raw or fresh peppers (bell and chili) can have important health benefits due to their high levels of vitamins, minerals, and antioxidants. Therefore, it is crucial to consider factors such as pesticide use and preparation methods to fully realize these benefits. Ensuring that the levels of pesticide residues in peppers are not harmful to human health requires rigorous and continuous monitoring. Several analytical methods, such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-Vis), and nuclear magnetic resonance spectroscopy (NMR), can detect and quantify pesticide residues in peppers. The choice of analytical method depends on the specific pesticide, that is being tested for and the type of sample being analyzed. The sample preparation method usually involves several processes. This includes extraction, which is used to separate the pesticides from the pepper matrix, and cleanup, which removes any interfering substances that could affect the accuracy of the analysis. Regulatory agencies or food safety organizations typically monitor pesticide residues in peppers by stipulating maximum residue limits (MRLs). Herein, we discuss various sample preparation, cleanup, and analytical techniques, as well as the dissipation patterns and application of monitoring strategies for analyzing pesticides in peppers to help safeguard against potential human health risks. From the authors' perspective, several challenges and limitations exist in the analytical approach to monitoring pesticide residues in peppers. These include the complexity of the matrix, the limited sensitivity of some analytical methods, cost and time, a lack of standard methods, and limited sample size. Furthermore, developing new analytical methods, using machine learning and artificial intelligence, promoting sustainable and organic growing practices, improving sample preparation methods, and increasing standardization could assist efficiently in analyzing pesticide residues in peppers.

Effect of Moisture Content Difference on the Analysis of Quality Attributes of Red Pepper (Capsicum annuum L.) Powder Using a Hyperspectral System

The variety of characteristics of red pepper makes it difficult to analyze at the production field through hyperspectral imaging. The importance of pretreatment to adjust the moisture content (MC) in the process of predicting the quality attributes of red pepper powder through hyperspectral imaging was investigated. Hyperspectral images of four types of red pepper powder with different pungency levels and MC were acquired in the visible near-infrared (VIS-NIR) and short-wave infrared (SWIR) regions. Principal component analysis revealed that the powders were grouped according to their pungency level, color value, and MC (VIS-NIR, Principal Component 1 = 95%; SWIR, Principal Component 1 = 91%). The loading plot indicated that 580-610, 675-760, 870-975, 1020-1130, and 1430-1520 nm are the key wavelengths affected by the presence of O-H and C-H bonds present in red pigments, capsaicinoids, and water molecules. The R² of the partial least squares model for predicting capsaicinoid and free sugar in samples with a data MC difference of 0-2% was 0.9 or higher, and a difference of more than 2% in MC had a negative effect on prediction accuracy. The color value prediction accuracy was barely affected by the difference in MC. It was demonstrated that adjusting the MC is essential for capsaicinoid and free sugar analysis of red pepper.

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.

Cinnamon and paprika oleoresin emulsions: A study of physicochemical stability and antioxidant synergism

Cinnamon and paprika oleoresins (CPO) are by-products of the spice Cinnamomum zeylanicum Blume and the fruit Capsicum annuum L., respectively. They present a hydrophobic nature and various active compounds that can act synergistically. However, they are both susceptible to degradation by light, oxygen, and temperature. This work aimed at identifying the synergistic effect of these oleoresin mixtures, incorporating them into emulsions and characterizing the obtained systems. The CPO concentration was 10%, and whey protein isolate (WPI), gum Arabic (GA), or maltodextrin (MD) were used as wall materials in different proportions, totalizing 30% solids. The synergistic effect was observed in the FRAP assay at a 1:1 CPO ratio, with its expected value being significantly higher than the values for individual oleoresins (p < 0.05). Emulsions containing GA were unstable, while the emulsions containing MD and WPI showed reduced droplet size and viscosity, remaining stable for 7 days. The sample with a 1:3 proportion of MD:WPI as wall material showed higher FRAP and ORAC antioxidant values (24.74 ± 0.83 and 28.77 ± 1.23 mmol TE/g of oleoresin, respectively) and 4.18 mg total carotenoids/g sample. These results suggest the emulsions have a protective effect on active compounds content and can be used as efficient delivery systems for food product applications.

Mathematical Modeling, Moisture Diffusion and Color Quality in Intermittent Microwave Drying of Organic and Conventional Sweet Red Peppers

The aims of this research were to evaluate the influence of intermittent microwave drying on the moisture diffusion and color qualities of organically and conventionally grown sweet red peppers and mathematically express drying kinetic data. Pepper samples of 150 g were dried at 150, 300 and 450 W using a microwave oven. Results showed that intermittent microwave drying at 450 W occurred mainly in the falling rate period, whereas drying at lower powers resulted in relatively longer constant rate periods for both peppers types. The Midilli model provided the best fit for all data. The moisture diffusivity (Deff) values of organic and conventional samples ranged from 59.69 × 10−10 to 182.01 × 10−10 m2s−1 and from 59.11 × 10−10 to 181.01 × 10−10 m2s−1, respectively, and the difference was insignificant. The pre-exponential factor for the Arrhenius equation (D0) and activation energy (Ea) values were almost identical for both product types. Overall, organic or conventional growing did not alter the structural features related to the heat transfer properties. Intermittent microwave drying at 150 and 300 W for organic peppers and 150 W for conventional peppers gave the highest ΔL*, Δa* and a*/b* values, producing the most bright and red pepper powders. Thus, these treatments can be used to produce higher color quality powders.

Effect of gamma radiation and storage at 4°C on the inactivation of Listeria monocytogenes, Escherichia coli and Salmonella enterica Typhimurium in Legon-18 pepper (Capsicum annuum) powder

Objectives

Spices are low moisture foods which have been known to be contaminated with various pathogens and sun-dried Legon-18 pepper powder is not left out. Due to its contamination with various pathogens, a study was conducted to determine the effects of gamma irradiation on the decontamination of Legon-18 pepper powder and on some quality parameters.

Methods

Samples were obtained from a local farmer from the Eastern Region of Ghana. Sterility tests were carried out. The samples were inoculated with known cfu/ml of Escherichia coli, Listeria monocytogenes and Salmonella enterica Typhimurium. Samples were irradiated at 1, 2, 4, and 5 kilogray (kGy). Zero kilogray served as control (unirradiated). All samples were stored at 4oC for 60 days. Enumeration of the various pathogens was done in appropriate media. Some quality parameters were determined after irradiating unsterile samples at 5 kGy and 0 kGy served as control. Capsaicinoids and carotenoids were quantified using a high performance liquid chromatography. The samples were stored at 4oC for 8 weeks.

Results

A dose-dependent effect on the inactivation of the pathogens was observed (P &lt; 0.05). Storage time affected the inactivation of the pathogens as well (P &lt; 0.05). Complete inactivation of the pathogens was observed at 5 kGy at day 0. Capsaicin, dihydrocapsaicin and total capsaicinoid content of the samples irradiated at 5 kGy increased at 23.64%, 14.7 % and 20.95% respectively as compared with the contents of the unirradiated samples. A gamma irradiation dose of 5 kGy caused losses of 8.11%, 8.67% and 26.54% in capsanthin, beta carotene and beta cryptoxanthin respectively. Quality parameters measured reduced with storage (P &lt; 0.05).

Conclusions

Gamma irradiation inactivated pathogens at 5 kGy. Lower doses used during the study could inactivate the pathogens but with time. All quality parameters and carotenoids quantified were affected by gamma irradiation and storage period (P &lt; 0.05).

Determination of Volatiles and Carotenoid Degradation Compounds in Red Pepper Fermented by Lactobacillus parabuchneri

Red pepper (Capsicum annuum L.) has been used as one of key ingredients in certain fermented foods due to it providing a unique hot and spicy sensation. In this study, volatile compounds-including degradation compounds of carotenoids-in fermented red pepper inoculated with Lactobacillus parabuchneri were investigated. In total, the contents of certain alcohols, benzene and its derivatives, esters, hydrocarbons, lactones, pyrazines, and terpenes were increased in red pepper inoculated with L. parabuchneri, while those of aldehydes, sulfur-containing compounds, and ketones decreased during the fermentation period. The contents of some degradation compounds of carotenoids (β-ionone, β-cyclocitral, α-ionone, and β-damascenone) increased significantly with the fermentation period. In particular, the content of β-damascenone-which could form by the degradation of neoxanthin-increased gradually during fermentation, but this compound was not detected in 0-day samples. These findings indicate that the contents of certain volatiles-including degradation compounds of carotenoids-in fermented red pepper inoculated with L. parabuchneri can change markedly during the fermentation process.

PRACTICAL APPLICATION

This study investigated the changes of volatiles and carotenoids degradation compounds in fermented red pepper inoculated with Lactobacillus parabuchneri during fermentation. These results could be used to improve the quality of red pepper-based products and in the development of certain fermented foods, including Gochujang (fermented red pepper paste) and kimchi.

Increasing solubility of red bell pepper carotenoids by complexation with 2-hydroxypropyl-β-cyclodextrin

Red bell pepper carotenoids were complexed with 2-hydroxypropyl-β-cyclodextrin (2-HPβCD) in different mass ratios (1:4, 1:6, 1:8 and 1:10) through ultrasonic homogenization in order to increase carotenoid solubility and their use as natural pigment in food. Inclusion complexes, red bell pepper extract and physical mixtures were analyzed by DSC, FT-IR, (1)H NMR and DLS. Solubility assay was performed to identify the effect of complexation on the solubility of carotenoids. From characterization assays, results showed that inclusion process occurred for all tested ratios. Results for water solubility assays demonstrated clear differences between solubility index of inclusion complexes (8.06±2.59-16.55±4.40mg/mL) and physical mixtures (3.53±1.44-7.3±1.88mg/mL), while carotenoid extract was no water soluble, as expected. These results indicated that molecular inclusion of carotenoids in 2-HPβCD was efficient to enhance their solubility in water, enabling application of red bell pepper carotenoid as natural pigment and/or bioactive substances in food.

Moisture content and its impact on aflatoxin levels in ready-to-use red chillies

Moisture content (MC) and aflatoxin contamination were analysed to determine Red Chilli quality. A wide range (9.1-19.8%) of MC with a mean value of 11.4 ± 2.4% was found. Of 116 chilli samples, about 37% had low MC (<10%), 29.4% had medium-low MC (10-12%), 18.9% had medium-high MC (12 < MC < 14%) and 14.7% were above 14%. These four chilli groups had average aflatoxin levels of 2.1 ± 1.1, 5.3 ± 4.2, 8.9 ± 5.9 and 37 ± 20 µg/Kg, respectively. A direct relationship between moisture and aflatoxin content was found. The data best fitted a polynomial trend (R² = 0.89). The obtained equation could be utilised to assess aflatoxin levels based on MC. This study highlights the importance of using properly dried chillies with low MC, that is, ≤10%, to minimise health hazards associated with aflatoxin contamination.

Identification of volatile organic compounds generated from healthy and infected powdered chili using solvent-free solid injection coupled with GC/MS: application to adulteration

To investigate adulteration in commercial chili powder, the volatile organic compounds of healthy and infected powdered chili pepper were characterized using a solvent-free solid injector (SFSI) coupled with gas chromatography/mass spectrometry (GC/MS). Except for one compound (capillary compound for blank), 43 compounds were identified in healthy and infected chili powder. Specifically, 31, 36, and 41 compounds were identified in healthy, medium-infected, and severely infected chili powder. Among these compounds, acetic acid (13.77%), propanal (2.477%), N-methylpyrrole (1.986%), and 2-methyl-propanal (1.768%) were leading volatiles in the healthy chili powder. In contrast, infected chili powder contained 9,12-octadecadienoic acid, ethyl ester (15.984%), acetic acid (11.249%), hexadecanoic acid, methyl ester (3.3%), N-methylpyrrole (3.221%), and 2-furanmethanol (2.629%) as major compounds. Trimethylamine and isosorbide were detected in both medium and severely infected chili, but not in healthy chili. This means that these compounds could be used as biomarkers to distinguish between healthy and infected chili. The proposed technique was applied to 12 commercial chili powders, and trimethylamine and isosorbide were detected in six samples. These results suggest that a contaminated chili that was added to a healthy one could be successfully identified by a combination of the SFSI and GC/MS.

Nitrogen-fixing bacteria with multiple plant growth-promoting activities enhance growth of tomato and red pepper

As a suitable alternative to chemical fertilizers, the application of plant growth-promoting rhizobacteria has been increasing in recent years due to their potential to be used as biofertilizers. In the present work, 13 nitrogen-fixing bacterial strains belonging to 11 different genera were tested for their PGP attributes. All of the strains were positive for 1-aminocyclopropane-1-carboxylate deaminase (ACCD), indole-3-acetic acid (IAA), salicylic acid, and ammonia production while negative for cellulase, pectinase, and hydrocyanic acid production. The strains Pseudomonas sp. RFNB3 and Serratia sp. RFNB14 were the most effective in solubilizing both tri-calcium phosphate and zinc oxide. In addition, all strains except Pseudomonas sp. RFNB3 were able to oxidize sulfur, and six strains were positive for siderophore synthesis. Each strain tested in this study possesses at least four PGP properties in addition to nitrogen fixation. Nine strains were selected based on their multiple PGP potential, particularly ACCD and IAA production, and evaluated for their effects on early growth of tomato and red pepper under gnotobiotic conditions. Bacterial inoculation considerably influenced root and shoot length, seedling vigor, and dry biomass of the two crop plants. Three strains that demonstrated substantial effects on plant performance were further selected for greenhouse trials with red pepper, and among them Pseudomonas sp. RFNB3 resulted in significantly higher plant height (26%) and dry biomass (28%) compared to control. The highest rate of nitrogen fixation, as determined by acetylene reduction assay, occurred in Novosphingobium sp. RFNB21 inoculated red pepper root (49.6 nM of ethylene/h/g of dry root) and rhizosphere soil (41.3 nM of ethylene/h/g of dry soil). Inoculation with nitrogen-fixing bacteria significantly increased chlorophyll content, and the uptake of different macro- and micro-nutrient contents enhancing also in red pepper shoots, in comparison with uninoculated controls. The population estimation studies showed that nitrogen-fixing as well as total heterotrophic bacteria were also noticeably increased in soil and plant samples. The findings of this study suggest that certain nitrogen-fixing strains possessing multiple PGP traits could be applied in the development of biofertilizers.

Inclusion complexes of red bell pepper pigments with β-cyclodextrin: preparation, characterisation and application as natural colorant in yogurt

This work aimed to prepare inclusion complexes between red bell pepper pigments and β-cyclodextrin using two different procedures (i.e., magnetic stirring and ultrasonic homogenisation), to characterise the prepared inclusion complexes and to evaluate the colour stability of a selected complex added to yogurt. The mass ratio of extract to β-cyclodextrin was 1:4. The formed extract: β-cyclodextrin complexes and a physical mixture of extract and β-cyclodextrin were evaluated by differential scanning calorimetry, Fourier transform-infrared spectroscopy, proton nuclear magnetic resonance, particle size distribution and Zeta potential. The obtained data showed that ultrasonic homogenisation resulted in better yield and inclusion efficiency compared to magnetic stirring. The yogurt with the added complex produced by ultrasonic homogenisation showed slower variations for the a(∗) (redness) and b(∗) (yellowness) indices compared to yogurt with added extract, indicating a higher protection of the colour during storage.

Physicochemical properties and sensory evaluation for the heat level (hot taste) of korean red pepper powder

This study investigated the heat level rating of several varieties of Korean red peppers. The chemical constitution of Korean red pepper samples were as follows: 0.54∼290.15 mg% capsaicinoids, 79.22∼139.09 ASTA value, and 16.76∼29.92% free sugar content. The heat level of the Korean red pepper samples was evaluated by trained panelists and the correlation coefficient and F value (0.001%) of the panelist's results were determined to be significant. In the principle component analysis (PCA), PC1 (capsaicinoids) and PC2 (free sugar) were shown to represent 31.98% and 25.77% of the total variance, respectively. The results of panelists trained for red pepper heat rating were evaluated using analysis of variance and correlation analysis. The trained panelists showed a high F value (p=0.05) and high correlation coefficient. A high correlation efficient of 0.84∼0.93 for the test samples with a 40 Scoville heat unit (32,000 SHU red pepper powder) was reported in the sensory evaluation of the Korean red pepper heat level by a trained panel. However, the panel showed a low correlation efficiency of 0.70 R(2) when the 60 SHU test samples were included in the analysis.

Influence of different drying methods on carotenoids and capsaicinoids of paprika (Cv., Jalapeno)

Influence of Refractance Window™ Drying (RWD), a novel contact drying method, on carotenoids, capsaicinoids, Retinol Activity Equivalent (RAE) and Scoville Heat Unit (SHU) of paprika (Cv., Jalapeno) was investigated in comparison with freeze drying (FD), oven drying (OD), and natural convective drying (NCD) methods. Eight carotenoids (capsanthin, capsorubin, capsolutein, β-carotene, β-cryptoxanthin, mutatoxanthin, violaxanthin and zeaxanthin) and five capsaicinoid analogues (capsaicin, dihydrocapsaicin, homodihydrocapsaicin, isodihydrocapsaicin, nordihydrocapsaicin) were identified in paprika. All these components were significantly (P<0.05) decreased by the RWD, FD and OD methods. However, due to ongoing synthesis, the NCD method resulted in higher carotenoids, except violaxanthin and mutatoxanthin, and capsaicinoids content than those of the others, even puree. Mutatoxanthin, naturally occurring pigment in red pepper, could only be detected in FD paprika. The highest RAE and SHU values, which were derived from the data of carotenoids and capsaicinoids, respectively, were also determined in NCD paprika.

Carotenoid composition and vitamin A value in ají (Capsicum baccatum L.) and rocoto (C. pubescens R. & P.), 2 pepper species from the Andean region

The carotenoid patterns of fully ripe fruits from 12 Bolivian accessions of the Andean peppers Capsicum baccatum (ají) and C. pubescens (rocoto) were determined by high-performance liquid chromatography (HPLC)-photodiode array detector (PDA)-mass spectrometry (MS). We include 2 California Wonder cultivars as C. annuum controls. A total of 16 carotenoids were identified and differences among species were mostly found at the quantitative level. Among red-fruited genotypes, capsanthin was the main carotenoid in the 3 species (25% to 50% contribution to carotenoid fraction), although ajíes contained the lowest contribution of this carotenoid. In addition, the contribution of capsanthin 5,6-epoxide to total carotenoids in this species was high (11% to 27%) in comparison to rocotos and red C. annuum. Antheraxanthin and violaxanthin were, in general, the next most relevant carotenoids in the red Andean peppers (6.1% to 10.6%). Violaxanthin was the major carotenoid in yellow-/orange-fruited genotypes of the 3 species (37% to 68% total carotenoids), although yellow rocotos were characterized by lower levels (<45%). Cis-violaxanthin, antheraxanthin, and lutein were the next most relevant carotenoids in the yellow/orange Andean peppers (5% to 14%). As a whole, rocotos showed the highest contributions of provitamin A carotenoids to the carotenoid fraction. In terms of nutritional contribution, both ajíes and rocotos provide a remarkable provitamin A activity, with several accessions showing a content in retinol equivalents higher than California Wonder controls. Furthermore, levels of lutein in yellow/orange ajíes and rocotos were clearly higher than California Wonder pepper (≥1000 μg·100/g). Finally, the Andean peppers, particularly red ajíes, can be also considered as a noticeable source of capsanthin, the most powerful antioxidant compound among pepper carotenoids. Practical Application: Capsicum peppers are known for their content in carotenoids, although there is no information about 2 species with Andean origin: ajíes and rocotos. Due to their relevance for the Andean cuisine and increasing importance in ethnic restaurants in Europe, we studied their carotenoid pattern and vitamin A contribution.

Carotenoids: actual knowledge on food sources, intakes, stability and bioavailability and their protective role in humans

Carotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re-examine the role of carotenoids in human nutrition. We have emphasized the attention on the following carotenoids present in food and human tissues: beta-carotene, beta-cryptoxanthin, alpha-carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures.