Red Bell Pepper Research Articles

Water extraction of plant tissues for analysis by ion chromatography1

High pressure liquid chromatography (HPLC)‐grade water was evaluated as an alternative extraction reagent to acid extraction of plant tissue. Green and red bell pepper fruit (Capsium annuum var. annuum L.), cultivar Pip; sweet corn internodes (Zea mays L.), cultivar Florida Staysweet; cabbage wrapper leaves (Brassica oleracea L. Capitata group), cultivar Solid Blue 770; peach leaves [Prunus persica (L.) Batsch], cultivar Coronet; and mixed leaves and stems of cotton (Gossypium hirsutum L.), cultivar Delta Pine 51; or okra [Abelmoschus esculentus (L.) Moench], cultivar Spineless Green Pod were extracted with HPLC‐grade water or 5 mM hydrochloric‐ (HCl), acetic‐, or citric‐acids. Ashed and fresh ground tissues were used for extraction with HCl. Cations and anions were determined by ion chromatography. In about 95% of occurrences, concentrations of ions in tissues extracted with HPLC‐grade water were equal to, or greater than, those extracted with acids. Therefore, extraction of plant tissues with HPLC‐grade water is recommended. Fewer waste disposal problems will also occur with water extraction of plant tissues.

Dynamics of Acetaldehyde Production during Anoxia and Post-Anoxia in Red Bell Pepper Studied by Photoacoustic Techniques.

Acetaldehyde (AA), ethanol, and CO2 production in red bell pepper (Capsicum annum L.) fruit has been measured in a continuous flow system as the fruit was switched between 20% O2 and anaerobic conditions. Minimum gas phase concentrations of 0.5 nL L-1, 10 nL L-1, and 1 mL L-1, respectively, can be detected employing a laser-based photoacoustic technique. This technique allows monitoring of low production rates and transient features in real time. At the start of anaerobic treatment respiration decreases by 60% within 0.5 h, whereas AA and ethanol production is delayed by 1 to 3 h. This suggests a direct slow-down of the tricarboxylic acid cycle and a delayed onset of alcoholic fermentation. Reexposure of the fruit to oxygen results in a 2- to 10-fold upsurge in AA production. A short anoxic period leads to a sharp transient peak lasting about 40 min, whereas after numerous and longer anoxic periods, post-anoxic AA production stays high for several hours. High sensitivity of the fruit tissue to oxygen is further evidenced by a sharp decrease in post-anoxic AA production upon an early return to anaerobic conditions. Ethanol oxidation by the "peroxidatic" action of catalase is proposed to account for the immediate post-anoxic AA upsurge.

Influence of Nitrogen Fertilization and Plastic Mulches on Insect Populations and Disease Incidence on Bell Peppers (Capsicum annuum)

Production of red bell peppers (Capsicum annuum L. cv. King Arthur) is relatively new to Quebec, and management techniques need to be further developed in terms of insect and disease control as well as fertigation techniques. The purpose of the experiment was to compare the fertigation of peppers using either the conventional method (weekly fertigation) or fertigation based on the readings of the SPAD 502 chlorophyll meter. The experiment compared the effects of these fertigation treatments, with respect to insects and diseases, on either a silver or black mulch. The study done in 1995, demonstrated that using the chlorophyll meter saved 28 kg N/ha compared to the weekly fertigated plants. However, this decrease did not affect the population of insects or the disease incidence on the plants. The main differences occurred between the black and silver mulch treatments for aphid populations. Plants on silver mulch had significantly lower numbers of aphids than the other treatments. Plants on black mulch also had low aphid population compared to plants grown on bare soil. The relationship between silver mulch and viruses or tarnished plant bug were not as apparent. However, the viral infections and tarnished plant bug populations on the plants tended to be lower than those on most of the black mulch treatments. Sunscald was not influenced by mulch or fertigation treatments. This may be partly attributed to the amount of leaf area. The number of fruit invaded by European corn borer was too low to draw any conclusions. Blossom end rot, sclerotinia, and bacterial spot were not present in the field in the 1995 season. The results from the 1996 season should further elucidate these results.

Reduction of chilling injury in stored avocado, grapefruit, and bell pepper by methyl jasmonate

Subjecting some chilling-sensitive commodities to various moderate stresses can cause them to acquire resistance to chilling injury. Jasmonates have been implicated in playing an integral role in the signal transduction cascade that operates in plants to induce responses to stress. Therefore, it was hypothesized that exogenous application of jasmonic acid or methyl jasmonate to chilling-sensitive commodities might replace the moderate stress treatment and reduce their chilling symptoms. To test this hypothesis, three chilling-susceptible fruits, avocado (Persea americana Mill., cvs. Hass, Etinger, and Fuerte), grapefruit (Citrus paradisi cv. Marsh seedless), and red bell pepper (Capsicum annum cv. Maor), were treated with various concentrations of methyl jasmonate prior to 4–10 weeks of storage at 2 °C. Results show that methyl jasmonate dipping (for 30 s) of avocado 'Fuerte' and 'Hass' (2.5 μM), avocado 'Etinger' or grapefruit (10 μM), and red bell pepper fruits (25 μM) significantly reduced both the severity of their chilling injury symptoms and the percentage of injured fruits. Application of methyl jasmonate by gassing for 24 h was similarly effective. In avocado 'Etinger', methyl jasmonate dipping was effective in alleviating chilling injury either after immediate storage at 2 °C or after the fruits had been held for 1 day at 20 °C prior to their storage at 2 °C. The results suggest that methyl jasmonate, which is receiving renewed biological interest as a potentially important signaling molecule in plants, might mediate the plant's natural response to chilling stress, and by its application might provide a simple means to reduce chilling injuries in chilling-susceptible commodities. Keywords: chilling injury, methyl jasmonate, postharvest treatment, stored fruits.

Cerebrosides in mature-green and red-ripe bell pepper and tomato fruits

Cerebrosides (CBs) isolated from pericarp lipids of green and red bell pepper and tomato fruits were separated by a new HPLC method into ⩾ six components. HPLC profiles were similar for the two fruits and changed little with ripening. CB 1 was the major peak, CB 2 was found only in bell pepper, and CBs 4, 5 and 6 were more abundant in pepper than in tomato. Total CBs and HPLC CB fractions were cleaved for analysis of fatty acid (FA), sphingoid (SP) and sugar moieties. FAs of total CBs were >95% saturated 2-hydroxyl. In CBs 1 and 2, 2-hydroxyl 16:0 was ⩾98% of the total FAs, whereas 2-hydroxyl 22:0, 23:0 and 24:0 predominated in CBs 4–6. The SPs of CBs 1 and 2 were tentatively identified as the 8- cis and 8- trans isomers of 4,8-sphingadienine and 8-sphingenine, respectively, whereas the SPs of CBs 4–6 were identified as isomers of 4-hydroxy-8-sphingenine. Glucose was the only sugar in bell pepper and tomato CBs. The major CB in both fruits was deduced to be 1- O- β-glucosyl- N-(2′hydroxypalmitoyl)-4- trans-8- cis-sphingadienine.

Chemoprevention of lung and skin cancer by Beta vulgaris (beet) root extract.

The in vitro inhibitory effect of Beta vulgaris (beet) root extract on Epstein-Barr virus early antigen (EBV-EA) induction using Raji cells revealed a high order of activity compared to capsanthin, cranberry, red onion skin and short and long red bell peppers. An in vivo anti-tumor promoting activity evaluation against the mice skin and lung bioassays also revealed a significant tumor inhibitory effect. The combined findings suggest that beetroot ingestion can be one of the useful means to prevent cancer.

Antioxidant Capacity of Tea and Common Vegetables

Previously, some fruits were shown to contain high antioxidant activities. In this paper, we report the antioxidant activities of 22 common vegetables, one green tea, and one black tea measured using the automated oxygen radical absorbance capacity assay with three different reactive species: a peroxyl radical generator, a hydroxyl radical generator, and Cu2+, a transition metal. Based on the fresh weight of the vegetable, garlic had the highest antioxidant activity (μmol of Trolox equiv/g) against peroxyl radicals (19.4) followed by kale (17.7), spinach (12.6), Brussels sprouts, alfalfa sprouts, broccoli flowers, beets, red bell pepper, onion, corn, eggplant (9.8−3.9), cauliflower, potato, sweet potato, cabbage, leaf lettuce, string bean, carrot, yellow squash, iceberg lettuce, celery, and cucumber (3.8−0.5); kale had the highest antioxidant activity against hydroxyl radicals followed by Brussels sprouts, alfalfa sprouts, beets, spinach, broccoli flowers, and the others. The green and black teas had much higher antioxidant activities against peroxyl radicals than all these vegetables. However, the tea also showed a prooxidant activity in the presence of Cu2+, which was not found with any of the vegetables studied. Keywords: Antioxidant; free radical; tea; vegetable

Model for Gas Exchange Dynamics in Modified‐Atmosphere Packages of Fruits and Vegetables

ABSTRACTA model for atmosphere in a package containing fresh fruits was analyzed theoretically and validated by experiments with red bell pepper fruit. The model was based on two processes: fruit respiration and film permeability. Mathematical analysis showed that when rates of O2 consumption and CO2 evolution due to respiration are equal, and film permeability to CO2 is greater than that to O2, the time course curve of CO2 concentration has a maximum. In a closed system, the time course of the sum of the gases could indicate a change of respiratory quotient. These results are independent of model for respiration. To predict extent of overshoot and for a computerized simulation, the equation of Michaelis‐Menten type with noncompetitive inhibition was adopted to describe respiration. Utilizing computer simulations enabled evaluation of film specifications and package dimensions best for a given commodity.

Characterization and Occurrence of Lipoxygenase in Bell Peppers at Different Ripening Stages in Relation to the Formation of Volatile Flavor Compounds

Extracts of green bell peppers (Capsicum annuum cv. Mazurka) were analyzed for the presence of lipoxygenase (LOX). A pH optimum of 5.5-6.0 was obtained, and enzyme activity was 100% and 51% inhibited by 10 mM n-propyl gallate and 340 μM 5,8,11,14-eicosatetraynoic acid (ETYA), respectively. When bell peppers ripened from green to completely red, LOX activity decreased 70%. Also, the composition of volatile breakdown products from unsaturated fatty acids changed drastically upon maturation. Four typical patterns for these volatile products could be distinguished during ripening ; some changed similarly to LOX activity. In both green and red bell pepper homogenates, the addition of linoleic acid increased considerably the levels of hexanal and hexanol, whereas the levels of (Z)-3-hexenal and (E)-2-hexenal were markedly enhanced by the addition of linolenic acid. When ETYA was added to these systems, the enhancing effects of both substrates were drastically reduced. A biochemical pathway was proposed for the formation of volatile bell pepper compounds upon tissue disruption.

Growth-regulator-induced Alleviation of Chilling Injury in Green and Red Bell Pepper Fruit during Storage

Bell pepper (Capsicum annuum L.) plants were sprayed at full bloom with paclobutrazol (50 and 100 mg·liter–1), uniconazole (20 and 50 mg·liter–1), or mefluidide (20 and 50 mg·liter–1). Mature-green and red fruit were harvested 4 and 8 weeks after spraying, respectively. Paclobutrazol and uniconazole, but not mefluidide, affected plant growth and fruit morphology. All three growth regulators alleviated chilling injury that developed on green and red peppers after 28 days at 2C. Potassium leakage was lower from tissue disks, and weight loss less, from treated fruit than from control fruit. Ethylene and CO2 production at 20C were similar in control and paclobutrazol-treated fruit after 28 days at 2C. These results are consistent with previous findings that showed these growth regulators are able to increase tolerance to low temperatures in whole plants. Chemical names used: N-[2,4-dimethyl-5-trifluoromethyl sulfonyl amino phenyl acetamide] (mefluidide); (2RS, 3RS) 1-(4-chlorophenyl)-4,4 dimethyl-2-(1,2,4-triazol-1-yl)-pentan-3-ol (paclobutrazol); (E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4 triazol-1-yl)-pentan-3-ol (uniconazole).

Improvement of the postharvest keeping quality and colour development of bell pepper (cv. ‘Maor’) by packaging with polyethylene bags at a reduced temperature

The keeping quality of red bell pepper (Capsicum annuum) is relatively low, since the fruits are sensitive to low temperature (< 7 °C), rot development and water loss. The effect of packaging red bell pepper fruits in various kinds of polyethylene bags, having various percentages of perforation (0.064 – 0.42%), was examined as a means of reducing water loss in fruits stored at the usual storage temperature (7–8 °C) and at 3 °C. In addition, prestorage holding of fruits for two-three days at various temperatures, combined with polyethylene-bag packaging was examined as a means of improving fruit colour development. Several beneficial effects were found: (1) polyethylene-bag packaging reduced water loss by 40–50% in fruits stored for two weeks at 7.5 °C and an additional three days at 17 °C, thereby resulting in maintenance of fruit quality; (2) packaging did not significantly increase rot development in the stored fruits during either storage or shelf-life; (3) polyethylene-bags enabled bell peppers to be stored at a reduced temperature (3 °C) without the appearance of chilling injury symptoms; (4) prestorage holding of peppers packed in perforated bags for two days at 25 °C, resulted in full red colour development at the end of their 12 days storage period, without loss of their firmness and quality.

Modified-humidity Packaging Reduces Decay of Harvested Red Bell Pepper Fruit

Lowering the in-package relative humidity (RH) by adding hygroscopic material (e.g., NaCl) reduced decay of bell pepper (Capsicum annuum L.) fruit sealed in low-density polyethylene and stored 2 or 3 weeks at 8C. Without hygroscopic material, the in-package RH was close to saturation, and water droplets condensed on the fruit and inner film surfaces. Depending on the amount of NaCl, condensation was prevented or significantly reduced. Humidity level varied from ≈88% with 15 g NaCl to ≈97% with 5 g NaCl for a package containing 0.5 to 0.6 kg of fruit. Adding hygroscopic material increased the water vapor pressure deficit (VPD) in the packages and, accordingly, the weight loss of the fruit. However, peppers packaged with NaCl still had lower weight loss and better quality than the nonsealed fruit. The water regime formed in four-fruit packages in the presence of 10 g NaCl (92% to 95% RH, VPD 65 to 77Pa) enabled optimal balance between reduced fruit desiccation and inhibited pathogen development, thus extending the postharvest life of bell pepper.

Changes in flavour release from rehydrated: Diced bell peppers (Capsicum annuum) by artificial saliva components in three mouth model systems

AbstractThe effect of artificial saliva components on flavour release from dehydrated diced red bell peppers (Capsicum annuum) was studied in a mouth model system. This measured the dynamic headspace under oral conditions, such as temperature, volume of the mouth, salivation, and mastication (DHM). The results were compared with a dynamic headspace (DH) and a purge‐and‐trap (PT) model system. Volatile compounds were analysed by gas chromatography, using flame ionisation detection (FID), mass spectrometry (MS), and sniffing port detection (SPD). SPD revealed that only 12 of the 47 compounds identified by MS and FID possessed odour activity. For all saliva compositions FID peak areas of volatile compounds were largest in the PT system, followed by DHM and DH, respectively. In the PT system the less volatile compounds were relatively better released than other volatile compounds in comparison with the DHM and DH system, for all salivas. The saliva components mucin and α‐amylase caused a relative decrease in release of the less volatile compounds in all model systems. An overall decrease in FID peak areas of volatile compounds by the latter components was observed in model system DH only.

Volatile compounds of rehydrated French beans, bell peppers and leeks. Part 1. Flavour release in the mouth and in three mouth model systems

Flavour release from three rehydrated vegetables: French beans, red bell peppers, and leeks, was studied directly in the mouth of 12 assessors (oral vapour) and in three mouth model systems; purge-and-trap, and dynamic headspace with and without mastication. Volatile compounds were analysed by gas chromatography and mass spectrometry, which resulted in 30, 52 and 42 identified compounds in French beans, bell, peppers, and leeks, respectively. Propanal, 2-methylpropanal, 2- and 3-methylbutanal, pentanal, hexanal, 2-pentenal, trans-2-hexenal, 2-heptenal, 2-butanone, and 6-methyl-5-hepten-2-one were present in each of them. Flavour release from the three vegetables in model system ‘dynamic headspace and mastication’ did not differ significantly from release in the mouth. Peak areas of volatiles released in the mouth had larger coefficients of variance than the ones released in the model system. Although assessors released volatile compounds with different efficiencies, they showed a statistically consistent efficiency in flavour release across the vegetables.

Volatile compounds of rehydrated French beans, bell peppers and leeks. Part II. Gas chromatography/sniffing port analysis and sensory evaluation

The flavours of rehydrated diced French beans, red bell peppers and leeks were characterised by gas chromatography/sniffing port analysis (GC/SP) of volatile compounds released in a mouth model system, and by descriptive sensory analysis. Volatile compounds were identified by combined gas chromatography/mass spectrometry. In French beans, bell peppers and leeks, respectively, 10, 16 and 22 compounds possessed detectable odours. A common odour profile was shown in the three vegetables. It comprised each of the odour active compounds present in French beans: i.e. 2-methylpropanal (chocolate), 2/3-methylbutanal (chocolate), 2,3-butanedione (caramel, fatty), hexanal (grassy, bell pepper), 2-methyl-2-butenal (chemical), octanal (sweet, sickly/musty, grassy, rancid), 1-octen-3-one (mushroom), dimethyl trisulphide (rotten, metal), 1-octen-3-ol (fatty, sickly/ musty, mushroom) and one unknown compound (chemical, rotten, rancid). The three vegetables differed markedly in GC/SP patterns and in scores for sensory attributes. Use of nose-clips diminished the scores for attributes in sensory analysis. In principal component analysis, correlation of rehydrated vegetables with sensory attributes and volatile compounds showed considerable contribution of volatile compounds to the flavour of rehydrated vegetables.

Gas Chromatography, Mass Spectrometry, and Sniffing Port Analyses of Volatile Compounds of Fresh Bell Peppers (Capsicum annuum) at Different Ripening Stages

Dynamic headspace gas chromatography, mass spectrometry, and sniffing port detection were used to analyze the volatile compounds of a Dutch commercial Capsicum cv. Mazurka at the ripening stages green, turning, and red. The samples were prepared by either cutting or blending of the fruits. The different bell pepper samples obtained had several odor compounds in common, i.e., 2,3-butanedione (caramel), 1-penten-3-one (chemical/pungent, spicy), hexanal (grassy), 3-carene (red bell pepper, rubbery), (Z)-β-ocimene (rancid, sweaty), octanal (fruity), and 2-isobutyl-3-methoxypyrazine (green bell pepper). During bell pepper maturation the majority of volatile compounds, of which several had green-related odor notes, decreased or even disappeared

Gas chromatography/sniffing port analysis and sensory evaluation of commercially dried bell peppers ( Capsicum annuum) after rehydration

Cultivated, cut and commercially dried red bell peppers (origins Chile, Hungary, and Turkey) were rehydrated and then evaluated by descriptive and hedonic panels. The types of pepper did not differ significantly in sensory values for the attributes cucumber, cooked vegetables, burned, mushrooms, bell pepper, fruity, grassy/green vegetables, fresh, spicy and sweet. The bell peppers of Chilean origin were rated higher in sour, bitter, sharp and pungent attributes than the Turkish, and higher in bitter and pungent attributes than the Hungarian. The Hungarian rated higher in ‘sour’ than the Turkish. Volatile compounds were analysed by gas chromatography, using flame ionisation detection, mass spectrometry and sniffing port detection. Forty-six compounds were identified, 12 of which possessed odours: 2-methylpropanal (chocolate); 2- and 3-methylbutanal (chocolate); 2,3-butadione (caramel/butter); 1-penten-3-one (plastic/chemical); hexanal (grassy/green); heptanal (lemon/orange); β-ocimene (fish/rotten/sickly); trans-3-hepten-2-one (mushrooms); dimethyltrisulphide (rotten/onion/leek); 2-methoxy-3-isobutylpyrazine (bell pepper); and β-cyclocitral (fruity). The compositions of the volatiles were similar for the three origins, although the Hungarian one generally exhibited the largest peak areas. The bell peppers from Chile were appreciated more by the panel than the ones from Turkey. This was probably due to the higher intensity of taste attributes (sour, bitter, sharp and pungent) because composition of the volatile compounds and intensity of odour attributes were similar for both origins.

The effects of controlled atmosphere storage at varying levels of relative humidity on weight loss, softening and decay of red bell peppers

The influence of controlled atmosphere (CA) storage on weight loss, softening and decay of red bell peppers was investigated for various levels of relative humidity (RH). The bell peppers were stored for 15 days at 8°C and 3% CO 2 3% O 2 or 0% CO 2 21% O 2 . For each gaseous condition four RH levels were tested (85, 90, 95 and 100%). This was followed by 7 days post-storage in air at 20°C and 70% RH. The incidence of fruit decay during post-storage increased with increasing levels of RH during storage. CA storage at 3% CO 2 3% O 2 reduced the incidence of fruit decay during post-storage compared with storage at 0% CO 2 21% O 2 . Weight loss and softening increased with decreasing levels of RH during storage, with no difference found between storage at 3% CO 2 3% O 2 and 0% CO 2 21% O 2 .

Quantitative Analysis of Carotenoids and Carotenoid Esters in Fruits by HPLC: Red Bell Peppers

ABSTRACTThe carotenoids of red bell peppers were analyzed without saponifi‐cation by high performance liquid chromatography using octadecyl silica as stationary and methanol‐ethyl acetate as mobile phases. The red bell peppers contained 280 ug/gm total carotenoids. Capsanthin accounted for 60% of the total carotenoids. Also present were 11%beta‐carotene and 20% capsorubin. Capsanthin was acylated with C12 to C18 saturated fatty acids.

Effects of Water Stress and Degree of Ripeness on Rate of Senescence of Harvested Bell Pepper Fruit

Abstract The physiological changes occurring in green and red bell pepper fruit (Capsicum annuum L. ‘Maor’) before and after harvest were investigated. Red pepper at harvest was less firm and had lower water potential, lower insoluble pectins, and higher water-soluble pectins than green bell pepper. However, the changes occurring in both types of peppers after harvest were similar. Postharvest weight loss was accompanied by a decrease in firmness, decrease in water potential, decrease in insoluble pectin, and an increase in soluble pectin in the cell wall. The production of CO2 showed that there was a slight decrease and a significant but small increase of ethylene after harvest. If weight loss was retarded by holding pepper in a water-saturated atmosphere, then all of these physiological changes were prevented or markedly slowed. It appears that water stress hastens and possibly triggers the onset of senescence in harvested bell pepper fruit.