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At least 325 records · Page 18Linked to original sources
PubMed2002

Pungency in paprika (Capsicum annuum). 2. Heterogeneity of capsaicinoid content in individual fruits from one plant.

The capsaicinoid content of individual fruits from a single plant harvested at the same time after flowering exhibits a wide range of values with a rather uniform pattern for the ratio of capsaicin, dihydrocapsaicin, and nordihydrocapsaicin. This observation is confirmed by the analysis of fruits from a second and third plant and for several harvest times at different stages of maturity. Competition with lignin-like material, environmental influences, and subcellular distribution may play a role in the synthesis and transformation of capsaicinoids.

Capsaicin↗
PubMed2001

Structure-reactivity relationship in the oxidation of carotenoid pigments of the pepper (Capsicum annuum L.).

The relationship between the degradation rate and structure of each pigment of the pepper carotenoid profile was studied in mixtures of dehydrated fruit with lipid substrates of differing degrees of unsaturation and in different proportions (20 and 40%). The differences in structural nature of the carotenoids present in the pepper fruit produce a variable rate of oxidation, resulting in nonuniform degradation. The yellow xanthophylls and beta-carotene have the highest rates of oxidation, with the ketocarotenoids and violaxanthin degrading at lower rates. Autoxidation is greater or lesser depending on the functional groups, which stabilize the radical intermediaries of the reaction. The behavior of capsanthin and capsorubin is that expected of carotenoids having structures that include keto groups: a markedly greater stability to autoxidation processes. This increases their antioxidant capacity, adding to their beneficial impact by reducing the proliferation of radical processes, which are detrimental to health.

Capsicum↗
PubMed2002

Purification of hydroperoxide lyase from green bell pepper (Capsicum annuum L.) fruits for the generation of C6-aldehydes in vitro.

The aim of this work was to compare the efficiency of different extracts of hydroperoxide lyase from green bell peppers in producing aldehydes: a crude extract, a chloroplastic fraction, and a purified enzyme were investigated. From a crude extract, the HPO lyase was purified by ion-exchange chromatography with a 22.3-fold increase in purification factor. Analysis by SDS-PAGE electrophoresis under denaturating conditions showed only one protein with a molecular weight of 55 kDa, whereas size-exclusion chromatography indicated a molecular weight of 170 kDa. A maximum of 7500 mg of aldehydes per g of protein was obtained with the purified enzyme within 20 min of bioconversion compared to 392 and 88 mg of aldehydes per g of protein within 50 and 60 min, respectively, for the chloroplast fraction and the crude extract.

Aldehyde-Lyases↗
PubMed2002

Capsaicinoids in vegetative organs of Capsicum annuum L. in relation to fruiting.

Pepper (cv. Padrón) shows a spatial gradient in the content of phenolic compounds, and particularly of capsaicinoids, along the stem. These compounds were consistently more abundant in apical fruits than in fruits belonging to middle and basal segments. Analysis of the two principal capsaicinoids in fruits showed that the proportion of capsaicin was always higher than that of dihydrocapsaicin. Capsaicinoids were also found to be present in vegetative organs, such as stem and leaves. In this case, the proportion of individual capsaicinoids was different than that in fruits, and dihydrocapsaicin was found to be more abundant. To find out whether the capsaicinoids in vegetative organs came from the fruits, the floral buds were removed and fruit formation was prevented. Capsaicinoids were not detected in the stem and leaves of floral bud-deprived plants, suggesting that they did originate from the fruit.

Capsaicin↗
PubMed2004

Changes in the carotenoid metabolism of capsicum fruits during application of modelized slow drying process for paprika production.

A temperature profile simulating the traditional slow drying process of red pepper fruits, which is conducted in La Vera region (Spain) for paprika production, was developed. Carotenoid and ascorbic acid content, as well as moisture of fruits, were monitored during the slow drying process designed. Data obtained suggested that the evolution of carotenoid concentration, the main quality trait for paprika, directly depend on the physical conditions imposed. During the drying process, three different stages could be observed in relation to the carotenoids. The first stage corresponds to a physiological adaptation to the new imposed conditions that implied a decrease (ca. 20%) in the carotenoid content during the first 24 h. After that short period and during 5 days, a second stage was noticed, recovering the biosynthetic (carotenogenic) capability of the fruits, which denotes an accommodation of the fruits to the new environmental conditions. During the following 48 h (third stage) a sharp increase in the carotenoid content was observed. This last phenomenon seems to be related with an oxidative-thermal stress, which took place during the first stage, inducing a carotenogenesis similar to that occurring in over-ripening fruits. Results demonstrate that a fine control of the temperature and moisture content would help to positively modulate carotenogenesis and minimize catabolism, making it possible to adjust the drying process to the ripeness stage of fruits with the aim of improving carotenoid retention and therefore quality of the resulting product. In the case of ascorbic acid, data demonstrated that this compound is very sensitive to the drying process, with a decrease of about 76% during the first 24 h and remaining only at trace levels during the rest of the process. Therefore, no antioxidant role should be expected from ascorbic acid during the whole process and in the corresponding final product (paprika), despite that red pepper fruit is well-known to be rich on this compound.

Capsicum↗
PubMed2006

Chlorophyll catabolism pathway in fruits of Capsicum annuum (L.): stay-green versus red fruits.

The aim of the present study is to investigate the chlorophyll catabolism pathway of wild-type red and stay-green mutants of Capiscum annuum (L.) fruits. In the wild-type red lines chlorophyll catabolism is concomitant with the start of carotenogenesis, whereas in the stay-green mutant lines the chlorophylls coexist with that process, even in over-ripe fruit. During the first stages of ripening, the chlorophyll a/chlorophyll b ratio is similar for both genotypes, but as ripening proceeds, the ratio in the stay-green lines becomes very high as a result of a blocked degradation of chlorophyll a while chlorophyll b is degraded at a normal rate. The absence of dephytylated chlorophylls in the wild-type lines distinguishes these from the mutant lines, in which there is a sequential accumulation of chlorophyllide a and pheophorbide a. Allomerized chlorophylls (13(2)-OH-chlorophyll a and b) have also been identified in the catabolic process of the mutant lines, but are absent from the wild type. Consequently, an alteration in pheophorbide a oxygenase (PaO) activity seems to be responsible for the stay-green genotype in the lines of pepper analyzed in this study.

Capsicum↗
PubMed1999

Firmness and phytochemical losses in pasteurized yellow banana peppers (Capsicum annuum) as affected by calcium chloride and storage.

The effect of calcium chloride brine treatment on firmness and retention of phytochemicals in pastuerized yellow banana peppers was studied. Shear force values declined during processing and storage, but CaCl(2) treatment resulted in greater firmness retention. Processing reduced ascorbic acid content by 63%, and after 124 days, <10% of ascorbic acid remained. Quercetin and luteolin contents declined 45% during processing, but levels stabilized during storage. Capsaicinoid content was stable during processing and storage. CaCl(2) treatment did not affect ascorbic acid, flavonoid, or capsaicinoid retention during pasteurization and storage. Retention of phytochemicals appeared to be related to their solubility and structural properties.

Calcium Chloride↗
PubMed1999

Paprika (Capsicum annuum) oleoresin extraction with supercritical carbon dioxide.

Paprika oleoresin was fractionated by extraction with supercritical carbon dioxide (SCF-CO(2)). Higher extraction volumes, increasing extraction pressures, and similarly, the use of cosolvents such as 1% ethanol or acetone resulted in higher pigment yields. Within the 2000-7000 psi range, total oleoresin yield always approached 100%. Pigments isolated at lower pressures consisted almost exclusively of beta-carotene, while pigments obtained at higher pressures contained a greater proportion of red carotenoids (capsorubin, capsanthin, zeaxanthin, beta-cryptoxanthin) and small amounts of beta-carotene. The varying solubility of oil and pigments in SCF-CO(2) was optimized to obtain enriched and concentrated oleoresins through a two-stage extraction at 2000 and 6000 psi. This technique removes the paprika oil and beta-carotene during the first extraction step, allowing for second-stage oleoresin extracts with a high pigment concentration (200% relative to the reference) and a red:yellow pigment ratio of 1.8 (as compared to 1.3 in the reference).

Capsicum↗
PubMed2000

Xanthophyll esterification accompanying carotenoid overaccumulation in chromoplast of Capsicum annuum ripening fruits is a constitutive process and useful for ripeness index.

Changes in xanthophyll esterification degree during pepper fruit ripening have been studied in five cultivars (Numex, Mana, Belrubi, Delfin, and Negral). Esterification of xanthophylls with fatty acids is seen to be a process that is contemporary with and directly linked to the transformation of chloroplast (present in the green fruit) into chromoplast (present in the red fruit). Changes in the fractions of free and partially and totally esterified carotenoids are similar between varieties, reflecting the constitutive nature of esterification as part of the ripening process and being controlled by it. From the first stages of ripening, the fraction of totally esterified pigments (zeaxanthin diester, beta-cryptoxanthin diester, capsanthin diester, and capsorubin diester) makes up almost 50% of the total carotenoid content. The proportion of the partially esterified pigment fraction (zeaxanthin monoester, capsanthin monoester, and capsorubin monoester) in the total carotenoid content increases, with a gradual decrease in the fraction of free pigments (beta-cryptoxanthin, beta-carotene, zeaxanthin, capsanthin, and capsorubin). In the fully ripe stage, a balance is reached between the three esterification fractions (free, partially esterified, and totally esterified), with mean values of 24.17 +/- 4.06, 31.48 +/- 4. 61, and 44.36 +/- 5.05, respectively, which seems to be largely independent of variety. This suggests a marked control of the carotenoid composition of the totally developed chromoplast, indicating its use as an index of ripeness. The inclusion in the present study of a variety (Negral) that retains chlorophylls when ripening, and which shows the same esterification behavior, supports the idea that carotenogenesis is normal and independent of chlorophyll catabolism.

Capsicum↗
PubMed2000

Selective enzyme-mediated extraction of capsaicinoids and caratenoids from chili guajillo puya (Capsicum annum L.) using ethanol as solvent.

The selective extraction of capsaicinoids and carotenoids from chili guajillo "puya" flour was studied. When ethanol was used as solvent, 80% of capsaicinoids and 73% of carotenoids were extracted, representing an interesting alternative for the substitution of hexane in industrial processes. Additionally, when the flour was pretreated with enzymes that break the cell wall and then dried, extraction in ethanol increased to 11 and 7% for carotenoid and capsaicinoid, respectively. A selective two-stage extraction process after the treatment with enzymes is proposed. The first step uses 30% (v/v) ethanol and releases up to 60% of the initial capsaicinoids, and the second extraction step with industrial ethanol permits the recovery of 83% of carotenoids present in the flour.

Capsaicin↗
PubMed1997

Isolation and characterization of a gene encoding endo-beta-1,4-glucanase from pepper (Capsicum annuum L.).

The endo-beta-1,4-glucanases, or cellulases, of higher plants are cell wall-associated enzymes believed to function in cell wall changes associated with the diverse processes of fruit ripening, organ abscission and cell elongation. We have isolated and characterized cDNA and genomic clones encoding a cellulase, PCEL1, which is abundant in ripening pepper fruit. Genomic analysis indicates that PCEL1 is encoded by a single gene, PCEL1, which belongs to a small, structurally divergent gene family. In ripening fruit, PCEL1 transcription is initiated at two distinct sites which yields overlapping mRNA species of 1.7 and 2.1 kb. High-level accumulation of both transcripts occurs in red fruit, while the 1.7 kb transcript is detected at a much lower level in stem and petiolar tissue. The increase in cellulase activity which is measured during fruit ripening is the product of PCEL1 expression and is tightly coupled to fruit reddening. High-level applications of ethylene serve to enhance the rate of ripening and the accumulation of PCEL1 mRNA. A direct role for ethylene in regulating PCEL1 expression is shown by the exclusive induction, in immature green fruit, of the 1.7 kb transcript in response to prolonged high-level exposure to ethylene--a pattern of expression not observed in fruit development on the vine.

Amino Acid Sequence↗
PubMed2001

Molecular cloning of a novel pathogen-inducible cDNA encoding a putative acyl-CoA synthetase from Capsicum annuum L.

By means of differential display, a pool of salicylic acid (SA)-induced mRNAs were identified and subsequently their cDNAs were isolated from a cDNA library prepared from SA-induced leaf tissues of hot pepper. One of these cDNA clones, designated CaSIG4, was 1900 bp and contained an open reading frame encoding 523 amino acids with a calculated molecular mass of 56.3 kDa. The predicted amino acid sequence of CaSIG4 showed high sequence similarity to the AMP-binding protein family of both prokaryotic and eukaryotic acyl-CoA synthetases. CaSIG4 transcripts accumulated rapidly after SA treatment and in response to both incompatible and compatible interactions with Xanthomonas campestris pv. vesicatoria race 1. To investigate the cis-acting elements mediating CaSIG4 expression, the CaSIG4 5'-flanking region was isolated by inverse PCR. Database searches indicated that a potential cis-regulatory element is almost identical to the consensus core sequences ACC(A/T)ACC(A/C) which are conserved among promoters of other phenylpropanoid biosynthetic genes. The subcellular localization of the CaSIG4 protein was studied by using a soluble modified GFP gene fusion delivered into epidermal cells of onion by biolistic bombardment. The CaSIG4-smGFP fusion protein was localized to the plasma membrane. Taken together, CaSIG4 encoding a putative acyl-CoA synthetase could function as a plasma membrane-bound protein with a role in signaling in plant defense.

Amino Acid Sequence↗
PubMed2003

Ferredoxin from sweet pepper (Capsicum annuum L.) intensifying harpin(pss)-mediated hypersensitive response shows an enhanced production of active oxygen species (AOS).

The hypersensitive response (HR) is a form of cell death associated with plant resistance to pathogen infection. Harpin(pss), an elicitor from the bacterium Pseudomonas syringae pv. syringae, induces a HR in non-host plants. Previously, we reported an amphipathic protein from sweet pepper interfering with harpin(pss)-mediated HR. In this report, we isolated and characterized a cDNA clone encoded that amphipathic protein from sweet pepper. This protein is designated as PFLP (plant ferredoxin-like protein) by virtue of its high homology with plant ferredoxin protein containing an N-terminal signal peptide responsible for chloroplast targeting and a putative 2Fe-2S domain responsible for redox activity. Recombinant PFLP obtained from Escherichia coli was able to significantly increase active oxygen species (AOS) generation when mixed with harpin(pss) in tobacco suspension cells. It also showed enhanced HR when co-infiltrated with harpin(pss) in tobacco leaves. We used a transgenic tobacco suspension cells system that constitutively expresses the Pflp gene driven by the CaMV 35S promoter to study the function of PFLP in enhancing harpin(pss)-mediated hypersensitive cell death in vivo. In response to harpin(pss), suspension cells derived from Pflp transgenic tobacco showed a significant increase both in the generation of AOS and in cell death as compared to the wild type. AOS inhibitors diphenylene iodonium chloride (DPI) and lanthanum chlorate (LaCl3) were used to study the involvement of AOS in harpin(pss)-induced cell death. Our results demonstrate enhanced generation of AOS is necessary to cause enhanced hypersensitive cell death in Pflp transgenic tobacco cells and it is plasma membrane-bound NADPH-oxidase-dependent. Sub-cellular localization studies showed that PFLP is present in the cytoplasm and chloroplast of Pflp transgenic tobacco cells, but only in the chloroplast, not in the cytoplasm, of wild-type tobacco cells. It is possible that PFLP can change the redox state of the cell upon harpin(pss) inoculation to increase AOS generation and hypersensitive cell death. Overall, this study will provide a new insight in the functional properties of ferredoxin in hypersensitive cell death.

Amino Acid Sequence↗