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PubMed2005

Characterization of carotenoids and carotenoid esters in red pepper pods (Capsicum annuum L.) by high-performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry.

Carotenoids and carotenoid esters were extracted from red pepper pods (Capsicum annuum L.) without saponification. Among the 42 compounds detected, 4 non-esterified, 11 mono- and 17 diesters were characterized based on their retention times, UV/Vis spectra and their fragmentation patterns in collision-induced dissociation experiments in atmospheric pressure chemical ionization mass spectrometry (APCI-MS). Positive and negative ion mode measurements were used for the characterization of major and minor carotenoids and their esters. Capsanthin esterified with lauric, palmitic and myristic acids represented the predominant compounds in the red pepper extracts. Additionally, three beta-cryptoxanthin and one zeaxanthin monoester were tentatively identified in red pepper pods for the first time. Furthermore, the specific fragmentation patterns of capsanthin-laurate-myristate and capsanthin-myristate-palmitate were used for the distinction of both regioisomers. The results obtained from LC-DAD-APCI-MSn experiments demonstrated that the carotenoid profile of red pepper pods is considerably more complex than considered hitherto.

Atmospheric Pressure↗

PubMed1995

Comparative effects of gamma and microwave irradiation on the quality of black pepper.

Powdered black pepper from Egyptian markets, was irradiated with different recommended doses of gamma rays (5.0 and 10.0 kGy) and with microwaves for different periods (20, 40 and 75 s) to improve its hygienic quality. The most common bacterial isolates were of three genera Bacillus, Clostridium and Micrococcus (7.5 x 10(6)), whereas the predominant fungi (7.8 x 10(4)) were Aspergillus species, A. glaucus, A. flavus, A. niger and A. ochraceus. Doses of gamma irradiation used (5.0 and 10 kGy) were sufficient to decrease spore-forming bacteria (SFB) and to inhibit the fungal flora and coliforms which contaminated the black pepper powder. Microwave treatments for 40 s and 75 s were of the same effectiveness whereas treatment for 20 s was less so. GLC analysis proved the presence of 31 peaks, only 19 compounds were identified as monoterpene hydrocarbons (56.21%), the major one being beta-phellandrene and limonene. Sesquiterpenes were also present, mainly beta-caryollphyllene (3.69%) as well as oxygenated compounds such as terpenol, geraniol, Me-chavicol, eugenol and anisol. Gamma irradiation at 5 kGy and 10 kGy respectively decreased the numbers of identified compounds from 21 (86.58% concentration) in untreated pepper to 16 (59.22% concentration), 15 (54.06% concentration). In comparison, microwave treatments, particularly for 40 s and 75 s, increased the concentration of the same compounds. The results obtained indicate that microwave treatment, under these conditions, is a safe and suitable technique for decontamination of black pepper which does not result in a great loss of flavour compounds, as compared with recommended doses of gamma irradiation.

Aspergillus↗

PubMed2002

Linkage of the A locus for the presence of anthocyanin and fs10.1, a major fruit-shape QTL in pepper.

The purple color of the foliage, flower and immature fruit of pepper ( Capsicum spp.) is a result of the accumulation of anthocyanin pigments in these tissues. The expression of anthocyanins is controlled by the incompletely dominant gene A. We have mapped A to pepper chromosome 10 in a Capsicum annuum (5226) x Capsicum chinense (PI 159234) F(2) population to a genomic region that also controls anthocyanin expression in two other Solanaceous species, tomato and potato, suggesting that variation for tissue-specific expression of anthocyanin pigments in these plants is controlled by an orthologous gene(s). We mapped an additional locus, Fc, for the purple anther filament in an F(2) population from a cross of IL 579, a C. chinense introgression line and its recurrent parent 100/63, to the same position as A, suggesting that the two loci are allelic. The two anthocyanin loci were linked to a major quantitative trait locus, fs10.1, for fruit-shape index (ratio of fruit length to fruit width), that also segregated in the F(2) populations. This finding verified the observation of Peterson in 1959 of linkage between fruit color and fruit-shape genes in a cross between round and elongated-fruited parents. The linkage relationship in pepper resembles similar linkage in potato, in which anthocyanin and tuber-shape genes were found linked to each other in a cross of round and elongated-tuber parents. It is therefore possible that the shape pattern of distinct organs such as fruit and tuber in pepper and potato is controlled by a similar gene(s).

Anthocyanins↗

PubMed2003

QTLs for resistance to powdery mildew in pepper under natural and artificial infections.

Epidemics of powdery mildew due to Leveillula taurica is an increasing problem in pepper production areas, particularly in coastal regions or greenhouse cultivation. The highly resistant genitor 'H3' was submitted to genetic analysis and QTL mapping in order to promote the introgression of its oligogenic resistance into large and sweet-fruited cultivars. The doubled-haploid progeny from the cross 'H3' (resistant) by 'Vania' (susceptible) was tested for resistance under both natural field infection and artificial inoculation tests, and QTL detection was compared for those two methods. Seven genomic regions including additive QTLs and epistatic interactions were detected, explaining altogether the major part of genotypic variance. Two genomic regions were common to both the evaluation methods, whereas other QTLs were method-specific, reflecting the environment dependence of powdery mildew epidemics. Orthologies with tomato genomic regions carrying resistance genes to L. taurica and Oidium lycopersicum were revealed by comparative mapping with pepper. Tight linkages between the detected QTLs and virus resistance or fruit color traits in pepper were also shown, which adds to the agronomic importance of these regions in pepper breeding programs.

Ascomycota↗

PubMed2004

Phenotypic and molecular evaluation of a recurrent selection program for a polygenic resistance to Phytophthora capsici in pepper.

'Criollo de Morelos 334' (CM334) is one of the most promising sources of resistance to Phytophthora capsici in pepper. This Mexican accession is distantly related to bell pepper and its resistance displays a complex inheritance. The QTLs involved in resistance to P. capsici were previously mapped. In order to transfer the resistance factors from CM334 into a bell pepper genetic background, a modified, recurrent breeding scheme was initiated. The breeding population was divided into three sub-populations which were screened by distinct phenotypic tests of increasing severity. The plants from the first sub-population were screened with low-severity tests and backcrossed to the susceptible bell pepper; the plants from the second and third sub-populations were screened by more severe resistance tests and crossed with the plants from the first and second sub-populations, respectively. In this study, the phenotypic data for the three sub-populations during five screening/intermating cycles were analysed. In parallel, the changes in allelic frequencies at molecular markers linked to the resistance QTLs were reported. The resistance phenotype and allelic frequencies strongly depended on the sub-population and screening severity. Regarding allelic frequency changes across the selection cycles, a loss of resistant QTL alleles was observed in the first sub-population, particularly for the low-effect QTLs, whereas a better conservation of the resistant QTL alleles was observed in the two other sub-populations. The same trend was observed in the phenotypic data with an increasing resistance level from the first to the third sub-populations. The changes in the allelic frequencies of loci not linked to resistance QTLs and for horticultural traits across the breeding process indicated that the recovery of the recipient parent genome was not significantly affected by the selection for resistance.

Analysis of Variance↗

PubMed2005

Comparative analyses of genetic diversities within tomato and pepper collections detected by retrotransposon-based SSAP, AFLP and SSR.

The retrotransposon-based sequence-specific amplification polymorphism (SSAP) marker system was used to assess the genetic diversities of collections of tomato and pepper industrial lines. The utility of SSAP markers was compared to that of amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. On the basis of our results, SSAP is most informative of the three systems for studying genetic diversity in tomato and pepper, with a significant correlation of genetic relationships between different SSAP datasets and between SSAP, AFLP and SSR markers. SSAP showed about four- to ninefold more diversity than AFLP and had the highest number of polymorphic bands per assay ratio and the highest marker index. For tomato, SSAP is more suitable for inferring overall genetic variation and relationships, while SSR has the ability to detect specific genetic relationships. All three marker results for pepper showed general agreement with pepper types. Additionally, retrotransposon sequences isolated from one species can be used in related Solanaceae genera. These results suggest that different marker systems are suited for studying genetic diversity in different contexts depending on the group studied, where discordance between different marker systems can be very informative for understanding genetic relationships within the study group.

Capsicum↗

PubMed2006

Response of pepper plants (Capsicum annum L.) on soil amendment by inorganic and organic compounds of arsenic.

The influence of soil contamination by inorganic and organic arsenic compounds on uptake, accumulation, and transformation of arsenic in pepper (Capsicum annum L.) was investigated in greenhouse pot experiments under controlled conditions. Pepper plants were cultivated in substrate amended by aqueous solutions of arsenite, arsenate, methylarsonic acid (MA), and dimethylarsinic acid (DMA) applied individually into cultivation substrate at concentrations of 15 mg As per kg of substrate. The plant availability of the arsenicals increased in the order arsenite = arsenate < MA < DMA. The highest arsenic concentrations were found in roots followed by stems, leaves, and fruits regardless of arsenic compound applied. In the control samples of pepper fruits, As(III), As(V), and DMA were present (25%, 37%, and 39% of the water-extractable arsenic). In control stems + leaves and roots, As(V) was the major compound (63% and 53% in a phosphate buffer extract) followed by As(III) representing 33% and 42%. Additionally, low concentrations (not exceeding 5%) of DMA and MA were detected as well. In all the soils analyzed after the first harvest of pepper fruits, arsenate was the dominating compound followed by arsenite. Methylarsonic acid, methylarsonous acid, and DMA were present at varying concentrations depending on the individual soil treatments. In the treated plants, the arsenic compounds in plant tissues reflected predominantly the extractable portions of arsenic compounds present in soil after amendment, and this pattern was more significant in the first part of vegetation period. The results confirmed the ability of generative parts of plants to accumulate preferably organic arsenic compounds, whereas in the roots and aboveground biomass, mainly inorganic arsenic species are present. Evidently, the source of soil arsenic contamination affects significantly the extractable portions of arsenic compounds in soil and subsequently the distribution of arsenic compounds within the plants.

Arsenates↗

PubMed2003

Establishment of a highly efficient transformation system for pepper (Capsicum annuum L.).

Application of modern genetic manipulation has been limited in pepper ( Capsicum annuum L.) due to the lack of an efficient transformation system. Following the development of an efficient protocol for in vitro regeneration of pepper cotyledons, we investigated the key factors affecting transformation and established a highly efficient genetic transformation system using the pepper cotyledon as starting material. In this system, cotyledon explants are preconditioned for 2 days on kanamycin (km)-free DM1 medium [Murashige and Skoog (MS) salts/Gamborg B5 vitamins basal medium supplemented with 20 g/l sucrose, 5,000 mg/l DJ nutrients and a hormone combination of 1.0 mg/l indoleacetic acid (IAA) and 5.0 mg/l 6-benzyladenine (BA) solidified with 0.7% agar, pH 5.8], followed by co-cultivation with Agrobacterium tumefaciens on DM1 for 2 days and delay selection on DM1 with 500 mg/l carbenicillin (carb) for 2 days. The explants are then placed on DM1 containing 10 mg/l AgNO(3), 50 mg/l km-sulfate and 500 mg/l carb. After 4-5 weeks, the explants with buds are transferred to EM1 medium (MS salts/Gamborg B5 vitamins basal medium supplemented with 20 g/l sucrose, 5,000 mg/l DJ nutrients, 10 mg/l AgNO(3) and a hormone combination of 1.0 mg/l IAA, 3.0 mg/l BA and 2.0 mg/l gibberellic acid, solidified with 0.7% agar, pH 5.8) with 50 mg/l kanamycin and 500 mg/l carbenicillin for the elongation of buds. After 3-6 weeks, 1- to 2-cm-long elongated shoots are excised and planted on RM1 medium (MS basal medium supplemented with a hormone combination of 0.2 mg/l NAA and 0.1 mg/l IAA, solidified with 0.8% agar, pH 5.8) with 25 mg/l km and 200 mg/l carb for rooting. We tested four genotypes of pepper, and all presented a high differentiation efficiency (81.3% on average), elongation rate (61.5%) and rooting efficiency (89.5%). Polymerase chain reaction analysis results showed that 40.8% of the regenerated plantlets were transgenic plants.

Adenine↗

PubMed2005

Successful development of a shed-microspore culture protocol for doubled haploid production in Indonesian hot pepper (Capsicum annuum L.).

Various systems of anther and microspore cultures were studied to establish an efficient doubled haploid production method for Indonesian hot pepper (Capsicum annuum L.). A shed-microspore culture protocol was developed which outperformed all the previously reported methods of haploid production in pepper. The critical factors of the protocol are: selection of flower buds with more than 50% late unicellular microspores, a 1 day 4 degrees C pretreatment of the buds, followed by culture of the anthers in double-layer medium system for 1 week at 9 degrees C and thereafter at 28 degrees C in continuous darkness. The medium contained Nitsch components and 2% maltose, with 1% activated charcoal in the solid under layer and 2.5 muM zeatin and 5 muM indole-3-acetic acid in the liquid upper layer. All the ten genotypes of hot pepper tested, responded to this protocol. The best genotypes produced four to seven plants per original flower bud. This protocol can be used as a potential tool for producing doubled haploid plants for hot pepper breeding.

Capsicum↗

PubMed2004

Isolation and functional characterization of the Ca-DREBLP1 gene encoding a dehydration-responsive element binding-factor-like protein 1 in hot pepper (Capsicum annuum L. cv. Pukang).

Through the use of subtractive hybridization analysis, we have identified 14 partial cDNA clones (pCa-DSRs) that are rapidly induced by dehydration in hot pepper (Capsicum annuum L.) roots. The predicted proteins encoded by Ca-DSRs are putatively involved in processes as diverse as primary and secondary metabolism, protein degradation, and stress responses, indicating the complexity of cellular responses to water deficit in hot pepper roots. Particularly, we investigated the detailed structural properties and expression profiles of Ca-DSR2 (Ca-DREBLP1: dehydration-responsive element binding-factor-like protein 1) encoding a protein that contains a single ERF/AP2 DNA-binding domain. Based on the conserved 14th valine and 19th glutamic acid residues in the ERF/AP2 domain, a basic amino acid stretch (PKKPAGRKKFR) near its N-terminal region, and DSAW signature sequence at the end of its ERF/AP2 domain, Ca-DREBLP1 was classified as a member of a DREB1-type subfamily. Gel retardation assays revealed that Ca-DREBLP1 was able to form a specific complex with the DRE/CRT motif, but not with the GCC box. When fused to the GAL4 DNA-binding domain, the Ca-DREBLP1(190-215) mutant could effectively function as a trans-activator in yeast. This suggests that the extreme C-terminal region plays an essential role in transcription activation. In hot pepper plants, Ca-DREBLP1 was rapidly induced by dehydration, high salinity and, to a lesser extent, mechanical wounding, but not by cold stress. Thus, although the structural features of Ca-DREBLP1 resemble those of the DREB1-type proteins of Arabidopsis thaliana and rice plants, its induction patterns are reminiscent of the DREB2-type proteins, indicating that Ca-DREBLP1 is a novel class DREB subfamily in hot pepper.

Amino Acid Sequence↗

PubMed2005

CaAlaAT1 catalyzes the alanine: 2-oxoglutarate aminotransferase reaction during the resistance response against Tobacco mosaic virus in hot pepper.

Hot pepper (Capsicum annuum L. cv. Bugang) plants exhibit a hypersensitive response (HR) upon infection by Tobacco mosaic virus (TMV) pathotype P0. To elucidate molecular mechanism that underlies this resistance, hot pepper cv. Bugang leaves were inoculated with TMV-P0 and genes specifically up-regulated during the HR were isolated by differential screening. One of the clones, CaAlaAT1 encoding a putative alanine aminotransferase (EC 2.6.1.2) exhibited organ-specific expression pattern and the transcript accumulated abundantly in red (ripe) fruit tissues. CaAlaAT1 transcript was also induced in older leaves during senescence. The expression of CaAlaAT1 gene was increased in the incompatible interaction with TMV-P0 but was not in the compatible interaction with TMV-P1.2. When a strain of Xanthomonas campestris pv. vesicatoria (Xcv) carrying an AvrBs2 gene was infiltrated into the leaves of a pepper cv. ECW 20R carrying Bs2 resistance gene, a marked induction and maintenance of CaAlaAT1 gene expression was observed. The expression of CaAlaAT1 gene was triggered by salicylic acid (SA) and ethylene but not by methyl jasmonate (MeJA). CaAlaAT1 seemed to be localized mostly at the cytosol from the polyethylene glycol (PEG)-mediated transformation experiment. CaAlaAT1 seemed to catalyze alanine: 2-oxoglutarate aminotransferase (AKT) reaction, which was a main activity among the four activities in vitro, during the resistance response against TMV in hot pepper. These results suggest that CaAlaAT1, a protein known to be involved in metabolic reactions, might be one of the components in the plant's defense signal pathway against pathogens.

Alanine Transaminase↗

PubMed2006

Functional roles of the pepper pathogen-induced bZIP transcription factor, CAbZIP1, in enhanced resistance to pathogen infection and environmental stresses.

Transcription factors often belong to multigene families and their individual contribution in a particular regulatory network remains difficult to assess. We identify and functionally characterize the pepper bZIP transcription factor CAbZIP1 gene isolated from pepper leaves infected with Xanthomonas campestris pv. vesicatoria. Transient expression analysis of the CAbZIP1-GFP fusion protein in Arabidopsis protoplasts revealed that the CAbZIP1 protein is localized in the nucleus. The N-terminal region of CAbZIP1 fused to the GAL4 DNA-binding domain is required to activate transcription of reporter genes in yeast. The CAbZIP1 transcripts are constitutively expressed in the pepper root and flower, but not in the leaf, stem and fruit. The CAbZIP1 gene is locally or systemically induced in pepper plants infected by either X. campestris pv. vesicatoria or Pseudomonas fluorescens. The CAbZIP1 gene is also induced by abiotic elicitors and environmental stresses. The CAbZIP1 transgenic Arabidopsis exhibits a dwarf phenotype, indicating that CAbZIP1 may be involved in plant development. The CAbZIP1 overexpression in the transgenic Arabidopsis plants confers enhanced resistance to Pseudomonas syringae pv. tomato DC3000, accompanied by expression of the AtPR-4 and AtRD29A. The transgenic plants also exhibit increased drought and salt tolerance during all growth stages. Moreover, the transgenic plants are tolerant to methyl viologen-oxidative stress. Together, these data suggest that the CAbZIP1 transcription factor function as a possible regulator in enhanced disease resistance and environmental stress tolerance.

Abscisic Acid↗

PubMed2004

Moderate drought influences the effect of arbuscular mycorrhizal fungi as biocontrol agents against Verticillium-induced wilt in pepper.

Previous studies have shown that the arbuscular mycorrhizal fungus (AMF) Glomus deserticola (Trappe, Bloss and Menge) can diminish the negative effect of Verticillium dahliae Kleb. on pepper yield. On the other hand, it is known that AMF can be more beneficial for plant growth and physiology under dry conditions than when soil moisture is plentiful. Therefore, our objective was to assess if a moderate water deficit imposed on pepper plants before their inoculation with V. dahliae could improve the effectiveness of G. deserticola as biocontrol agent. In the present experiment, the delay in disease development in Verticillium-inoculated plants associated with AMF did not occur under well watered conditions. In addition, the establishment of mycorrhizal symbiosis and the development of structures by AMF were delayed when both symbiotic and pathogenic fungi infected the same root. Therefore, it is suggested that the equilibrium between pepper plant, G. deserticola and V. dahliae is so complex that small changes in competition between symbiotic and pathogenic fungi for host resources can modify the efficiency of AMF as a biocontrol agent. On the other hand, water deficit enhanced the deleterious effect of V. dahliae on fruit set and yield only when pepper plants were not associated with G. deserticola, which reinforces the idea that AMF may be more important for host plants subjected to stressful conditions. However, comparing well watered non-mycorrhizal and predroughted mycorrhizal plants, we found that moderate water deficit imposed before inoculation with V. dahliae did not improve the effectiveness of G. deserticola as a biocontrol agent.

Antibiosis↗

PubMed2005

Integration of mutations responsible for the attenuated phenotype of Pepper mild mottle virus strains results in a symptomless cross-protecting strain.

An enhanced attenuated strain of Pepper mild mottle virus (PMMoV) was constructed by incorporating mutations that affect viral attenuation from three reported attenuated strains of PMMoV, which causes serious economic losses in the production of green pepper in Japan. The new strain caused no symptoms on pepper plants and protected them from infection by a wild-type strain. The mutations responsible for viral attenuation were located in the intervening region (IR) of the 126-kDa/183-kDa proteins. The mutations had synergistic effects in terms of the attenuation of symptoms and decreased the accumulation of the viral coat protein in infected pepper plants. In this paper, we propose an efficient method for the improvement of attenuated viruses by reverse genetics in plant viruses.

Base Sequence↗

PubMed2006

Identification and functional expression of the pepper pathogen-induced gene, CAPIP2, involved in disease resistance and drought and salt stress tolerance.

A novel pathogen-induced gene, designated CAPIP2, was isolated from pepper leaves infected with Xanthomonas campestris pv. vesicatoria. CAPIP2:GFP fusion proteins were primarily localized in the cytoplasm. The CAPIP2 transcripts were constitutively expressed in the pepper leaves, flowers, and fruits, but were not detected in the stems and roots. CAPIP2 gene expression was induced strongly in the pepper leaves during pathogen infection, and also after exposure to abiotic elicitors and environmental stresses. Ectopic CAPIP2 expression in Arabidopsis was accompanied by the expression of Arabidopsis PR-1 and PDF1.2 genes. Overexpression of the CAPIP2 gene in Arabidopsis transgenic plants conferred enhanced resistance to Pseudomonas syringae pv. tomato DC3000. The CAPIP2 transgenic Arabidopsis also manifested increased tolerance to high salt, drought and oxidative stress during seed germination and seedling state. These results suggest that pepper CAPIP2 gene may function as a defense-related gene against both biotic and abiotic stresses.

Amino Acid Sequence↗

PubMed1996

Comparison of dilution schemes for enumerating fungi in ground pepper: a collaborative study.

Ten lots of ground pepper were analyzed for fungal populations using 1:5 and 1:10 dilutions in sterile 0.1% peptone. Duplicate samples (0.1 ml) diluted 1:5 were surface plated on dichloran rose bengal chloramphenicol (DRBC) agar whereas quadruplicate samples (0.1 ml) diluted 1:10 were surface plated on DRBC agar. Nine collaborators from six countries participated in the study. Significantly (p < 0.05) higher fungal populations were detected in 7 of the 10 lots of pepper diluted using the 1:5 dilution scheme; the other three showed no significant difference. Using 1:5 and 1:10 dilution schemes, among-laboratory variability in mean fungal populations detected was not significant (p < 0.05) for 7 of 10 and 2 of 10 lots of peppers, respectively. Coefficients of variation for reproducibility (among-laboratory variation) were 2.8% and 6.2%, respectively, using 1:5 and 1:10 dilution schemes. Analysis of collapsed data from all ten lots of pepper revealed that significantly higher populations of fungi were detected using a 1:5 dilution scheme.

Colony Count, Microbial↗

PubMed2006

Use of pepper crop residues for the control of root-knot nematodes.

The biofumigant effect of pepper crop residues (PCR) for controlling Meloidogyne incognita populations was evaluated. Under laboratory conditions, 0, 5, 10 and 20 g PCR were applied to 500 g nematode infested soil, with four replicates per treatment. After 20 days at 25 degrees C, PCR reduced significantly M. incognita populations and root galling indices in susceptible tomato cv. Marmande, and increased K, N and organic C in soil. In the field, biofumigation with PCR combined with fresh animal manures (with and without plastic cover), methyl bromide, and a control were evaluated through root galling indices on a pepper crop. Each treatment, except for the control, had a grafted and non-grafted susceptible pepper sub-treatment, with three replicates. Root galling indices were lower, and yields higher, on grafted plants, biofumigation with PCR and plastic cover, with similar values as MB treatment, suggesting that biofumigation with PCR is an efficient non-chemical alternative to control M. incognita populations, especially when applied with plastic cover, nitrogen-rich organic matter and followed by grafting on resistant pepper.

Animals↗

PubMed2006

An ESR protocol based on relaxation phenomena of irradiated Japanese pepper.

We found various free radicals in a commercially available pepper in Japan before and after irradiation using electron spin resonance (ESR) spectroscopy. The typical ESR spectrum of the pepper consists of a sextet centered at g = 2.0, a singlet at the same g-value and a singlet at g = 4.0. Upon gamma ray irradiation, a new pair of signals appeared in the pepper. The progressive saturation behavior (PSB) at various microwave power levels indicated quite different relaxation behaviors of those radicals. Namely, the peak intensity of the organic free radical component decreases in a monotonic fashion, whereas the Mn2+ and Fe3+ ESR signals substantially keep constant. This reflects the evidence of three independent radicals in the pepper before irradiation. The PSB of the pair peaks as induced by irradiation possessed quite different PSB from that of the free radical located at g = 2.0. We proposed a new protocol for the ESR detection of irradiated foods by the PSB method at different microwave power levels. This would call for a major modification of the CEN protocol in European Union.

Dose-Response Relationship, Radiation↗