Common Bean Samples Research Articles

Zinc determination in common beans by pXRF: An easy and versatile calibration strategy applied to biofortification studies

Zinc deficiency is observed in millions of individuals, especially in underdeveloped countries. Therefore, agronomical strategies have been implemented to mitigate this public health issue, mainly by the biofortification of staple food crops, e.g., common beans, one of the most consumed leguminous grains worldwide. Accurate Zn determination by an analytical method is one of the most relevant steps in these initiatives. This study evaluated three calibration methods for Zn determination by portable X-ray Fluorescence Spectrometry (pXRF) in pelletized common bean samples. A Ti/Al primary filter and a 10-second irradiation time were selected as optimized operating conditions. The sample with the highest Zn content was submitted to acid extraction with diluted HCl and HNO3 to obtain synthetic blanks. Increasing amounts of the original sample were mixed with the obtained blanks to prepare the calibration curves standards. An additional calibration model with plant-based CRMs was also evaluated. Zinc mass fractions calculated using the calibration model of HCl-extracted and mixed samples showed statistical agreement with the reference data as demonstrated by the Student t-test at a 95 % confidence level. The linear correlation factor (r) was greater than 0.99, with a detection limit as low as 2.23 mg kg−1. The obtained calibration model also exhibited high prediction capability, as revealed by the low RMSEP (Root Mean Square Error of Prediction), i.e., 2.16 mg kg−1. We concluded that pXRF is an attractive and cost-effective method for direct, quick, and environmentally friendly Zn determination in common beans.

Nutritional properties of common bean protein concentrate compared to commercial legume ingredients for the plant-based market

There is an enormous demand to develop new sources of proteins, mainly to supply the growing plant-based food market worldwide, with the push for more sustainable and healthier products. The objective of this study was to evaluate the composition and the nutritional properties of commercial soybean, pea, and fava bean protein ingredients and compare them with an in-house ingredient (flour and protein concentrate), obtained from the main Brazilian cultivar of common bean (Phaseolus vulgaris, Pinto bean). The protein content of the common bean concentrate (79.75%) was as high as other commercial proteins isolated from the pea and higher than the others concentrates. All the ingredients presented the minimum amounts of indispensable amino acids as required by FAO and all ingredients were rich in lysine and leucine, with the highest amounts found for pea (78.06 mg/g) and common bean (86.70 mg/g) concentrates. A diverse mineral composition was reported for all the ingredients and the common bean concentrate presented the highest iron content (342.6 mg/kg). In terms of antinutritional factors, the common bean flour and concentrate showed the highest values for trypsin inhibitor (18 and 27 TIU/mg, respectively) but the lowest ones for phytic acid (9 and 2 mg/g, respectively) compared to the other ingredients. Low amounts of oligosaccharides were found in most of the samples. All proteins from the ingredients were highly digested when evaluated in vitro, but phaseolins fraction protein from common bean samples remained partially undigested. Despite compositional differences between ingredients, all samples should be suitable as protein sources for plant-based food innovation.

Pesticide residues determination in common bean using an optimized QuEChERS approach followed by solvent exchange and GC-MS/MS analysis.

Common bean is a staple food in Latin America and Africa; however, studies about contamination of common bean with pesticides are rarely reported. So, the goals of this study were to validate a multiresidue method and apply it in monitoring of pesticides in common beans. Extraction was performed applying the QuEChERS (quick, easy, cheap, effective, rugged, and safe) approach to ground samples. Octadecylsilane and primary-secondary amine were used for clean-up, and a solvent exchange step was performed before injection for gas chromatography-tandem mass spectrometry analysis. Method validation was done analyzing blank samples spiked at 20, 30, 50, and 100 μg kg-1 (n = 5). Linearity and linear range were assessed by the analysis of standard solutions at concentrations of 5, 15, 25, 50, 75, 100, and 150 μg L-1 . The method was successfully validated for 91 (64.1%) of the 142 compounds studied (139 pesticides and three degradation products). Limits of quantification were equal to 20 μg kg-1 , 30 μg kg-1 , 50 μg kg-1 , and 100 μg kg-1 for 18 (12.7%), 17 (12.0%), 21 (14.8%) and 35 (24.6%) compounds respectively. Fifteen (10.6%) compounds were not detected at any level, and 36 (25.4%) did not fulfill the requirements for a quantitative method. Sixteen common bean samples of South of Brazil were analyzed. Two samples were positive: one for tebuconzole and a second for picoxystrobin, permethrin, and cyproconazole. Cyproconazole is not allowed for use in the common bean crop, its use being a violation. As demonstrated, the validated approach is suitable for pesticide residues determination in common bean. Results of the sample analysis show that the control of pesticide residues in common bean is necessary to ensure food safety. © 2020 Society of Chemical Industry.

Procjena količine makro- i mikroelemenata u hrvatskim tradicijskim kultivarima graha (Phaseolus vulgaris L.) korištenjem spektroskopije u bliskome infracrvenom području (NIRS)

In this study, near-infrared spectroscopy (NIRS) was used to predict the contents of essential macro- and microelements in common bean (Phaseolus vulgaris L.) accessions of most widespread Croatian landraces. Total of 175 samples were used for the model development by modified partial least square (MPLS), principal component regression (PCR) and partial least square (PLS) techniques. Based on the coefficients of determination (R2), standard error of calibration (SEC) and error of prediction (SEP) the models developed were (i) nearly applicable for nitrogen (N) (0.89, 0.12 and 0.45 respectively), (ii) poor for iron (Fe), cinc (Zn), potassium oxide (K2O) and potassium (K), (iii) usable for phosphorus pentoxide (P2O5), phosphorus (P), phytic acid (PA) and manganese (Mn). The MPLS regression statistics suggested the most accurate models developed comparing with PLS and PCR. It was concluded that a wider set of common bean samples needs to be used for macro- and microelements prediction by NIRS.

First Report of Cowpea Polero Virus 1 (CPPV1) Infecting Cowpea in Kenya

Cowpea is an important legume crop for nutritional security, livestock feed and source of income in Kenya. Cowpea yield in Kenya is very low and declining further due to high incidences of pests and diseases among other factors. Like other pathogens, viruses have continued to cause yield losses of up to 100% depending on the prevailing epidemiological factors. This study had sought to determine the distribution, prevalence and genetic diversity of Cowpea Mild Mottle Virus (CPMMV) in western Kenya. Two surveys were conducted in the main legume growing areas of western Kenya. A total of 139 legume leafy samples were collected from 5 Counties; Bungoma, Nandi, Vihiga, Kakamega and Busia in June and October 2016. Collected samples were analyzed by Double Antibody Sandwich Enzyme Linked Immunosorbent Assay (DAS–ELISA) for detection CPMMV. ELISA was not carried out to test for CPPV1. Total RNA was extracted from the symptomatic leaf samples using RNeasy Mini Kit (Qiagen) according to the manufacturers’ protocol. Next Generation Sequencing (NGS) protocol proceeded. Assembled contigs were then subjected to a BLASTn search against the Genbank database. Phylogenetic analyses and comparisons were performed using MEGA X. Symptoms observed on legumes in the fields were mosaic, severe yellowing, chlorotic blotches and downward leaf curling. Some of the groundnut, cowpea and common bean samples collected in June and October tested CPMMV positive by DAS-ELISA. Legume samples of soybean, lablab, green grams, bambara nuts and legume weed collected tested negative for CPMMV. Results from Next Generation Sequencing technique revealed the presence of Cowpea Polero Virus 1 (CPPV1), the first full-length CPPV1 report and sequence to be reported in Eastern Africa. Phylogenetic analysis of VCP1 Kenyan isolate sequence revealed 98.27% similarity with that of Burkina faso isolate BE 167 (KY364846.1) (Palanga et al., 2017) and they clustered together. Kenyan isolate VCP1 and the Burkina faso BE 167 isolate are closely related. It is not clear if the spread of CPPV1 is through international trade from either country. Revelation of CPPV1 show that there could be more viruses affecting legume crops in the region whose identities are still unknown. There is need to conduct more diagnosis using NGS technique to detect more unknown but occurring viruses in the region. CPPV1 has been found infecting cowpea in Burkina faso, to the best of our knowledge this is the first report of CPPV1 in Kenya.

Metabolic switching of astringent and beneficial triterpenoid saponins in soybean is achieved by a loss-of-function mutation in cytochrome P450 72A69.

Triterpenoid saponins are major components of secondary metabolites in soybean seeds and are divided into two groups: group A saponins, and 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) saponins. The aglycone moiety of group A saponins consists of soyasapogenol A (SA), which is an oxidized β-amyrin product, and the aglycone moiety of the DDMP saponins consists of soyasapogenol B (SB). Group A saponins produce a bitter and astringent aftertaste in soy products, whereas DDMP saponins have known health benefits for humans. We completed map-based cloning and characterization of the gene Sg-5, which is responsible for SA biosynthesis. The naturally occurring sg-5 mutant lacks group A saponins and has a loss-of-function mutation (L164*) in Glyma15g39090, which encodes the cytochrome P450 enzyme, CYP72A69. An enzyme assay indicated the hydroxylase activity of recombinant CYP72A69 against SB, which also suggested the production of SA. Additionally, induced Glyma15g39090 mutants (R44* or S348P) lacked group A saponins similar to the sg-5 mutant, indicating that Glyma15g39090 corresponds to Sg-5. Endogenous levels of DDMP saponins were higher in the sg-5 mutant than in the wild-type lines due to the loss of the enzyme activity that converts SB to SA. Interestingly, the genomes of palaeopolyploid soybean and the closely related common bean carry multiple Sg-5 paralogs in a genomic region syntenic to the soybean Sg-5 region. However, SA did not accumulate in common bean samples, suggesting that Sg-5 activity evolved after gene duplication event(s). Our results demonstrate that metabolic switching of undesirable saponins with beneficial saponins can be achieved in soybean by disabling Sg-5.

Analysis of AFLP Markers for Screening Resistance to Common Bean Roots Rot (Pythium spp.)

Aims: To investigate AFLPs for suitability as potential markers for identification of sources of Pythium resistance in bean genotypes preferred by poor small holder farmers. Place and Duration of Study: Department of biological sciences Masinde Muliro University of Science and Technology, Kenya and Bangor University, North Wales, United Kingdom, between September 2010 and December 2012. Methodology: 45 common bean accessions comprising 35 seed samples collected from farmers, market centers, as well as seed stockists and ten common bean lines generated from a conventional breeding program with differential resistance to the pathogen Pythium were subjected to AFLP analysis. Genetic characterization using cluster and principal component analysis were conducted to determine segregating patterns of bean accessions in relation to tolerant and Original Research Article Maryrose et al.; AJEA, 5(4): 374-391, 2015; Article no.AJEA.2015.039 375 susceptible bean lines. Average genetic distances were calculated and similarity coefficients subjected to unweighted pair group method of arithmetic averages to generate dendograms. Results: Two informative AFLP primer combinations yielded 194 polymorphic loci. Genetic distance of bean samples from KARI Kakamega had 56 to 414 base pairs with a variability index of 0.63 to 0.90. Combined analysis of bean accessions from KARI breeding program and market class common bean samples revealed a variability index range of 0.62 to 0.90 with 56 to 420 base pairs. PCA contributed about 51.58% on the genetic variation. Cluster analysis of the 10 KARI-Kakamega bean lines revealed that resistant bean varieties were genetically different from the susceptible bean varieties. The dendogram generated revealed four sub-groups and with the exception of Alulu, a mildly resistant cultivar, that segregated alongside resistant cultivars, resistant varieties clustered differently from susceptible cultivars. However, screening with farmers’ germplasm produced a dendogram that revealed a mixture of distinct and relatively non-distinct categorization with regard to resistance. Only resistant cultivars AN1062, R2075, R719 and R1946 and susceptible cultivars GLP2 and GLP585 clustered together as expected. The others segregated randomly alongside the farmers’ germplasm. Resistant varieties AND1062, R2075, R719, R1946 and SCAM80 were more genetically related to marketable class of beans. R1946 R719, R2075 and AND1062 are closely related genetically compared to Mw001, KK15, Alulu and GLP2. Conclusion: AFLP is a relatively informative technique that has a great potential of delineating susceptible and resistant Pythium root rot dry bean varieties, and can be used as a preliminary guide to carry out further analysis. It is notable that the AFLP markers used were not able to clearly distinguish all the cultivars comprehensively and should not be used alone in determining resistance levels. The information generated in this study will contribute to the propagation of acceptable market class bean lines with resistance to Pythium root rot for improved livelihood and increased food security.

A specific endogenous reference for genetically modified common bean (Phaseolus vulgaris L.) DNA quantification by real-time PCR targeting lectin gene.

The Embrapa 5.1 genetically modified (GM) common bean was approved for commercialization in Brazil. Methods for the quantification of this new genetically modified organism (GMO) are necessary. The development of a suitable endogenous reference is essential for GMO quantification by real-time PCR. Based on this, a new taxon-specific endogenous reference quantification assay was developed for Phaseolus vulgaris L. Three genes encoding common bean proteins (phaseolin, arcelin, and lectin) were selected as candidates for endogenous reference. Primers targeting these candidate genes were designed and the detection was evaluated using the SYBR Green chemistry. The assay targeting lectin gene showed higher specificity than the remaining assays, and a hydrolysis probe was then designed. This assay showed high specificity for 50 common bean samples from two gene pools, Andean and Mesoamerican. For GM common bean varieties, the results were similar to those obtained for non-GM isogenic varieties with PCR efficiency values ranging from 92 to 101 %. Moreover, this assay presented a limit of detection of ten haploid genome copies. The primers and probe developed in this work are suitable to detect and quantify either GM or non-GM common bean.

Near-Infrared Spectroscopy Analysis of Seed Coats of Common Beans (Phaseolus vulgaris L.): A Potential Tool for Breeding and Quality Evaluation

Near-infrared spectroscopy (NIRS) is a well-established technique for determining the components of foods. Sample preparation for NIRS is easy, making it suitable for breeding and/or quality evaluation, for which a large number of samples should be analyzed. We aimed to assess the feasibility of NIRS to estimate parameters that seem to influence consumers' perception of the seed coat of common beans: dietary fiber (DF), uronic acids (UA), ashes, calcium, and magnesium. We used reference methods to analyze ground seed coats of 90 common bean samples with a wide range of genetic variability and cultivated at many locations. We registered the NIR spectra on intact beans and ground seed coat samples. We derived partial least-squares (PLS) regression equations from a set of calibration samples and tested their predictive power in an external validation set. For intact beans, only RER values for ashes and calcium are good enough for very rough screening. For ground seed coat samples, the RPD and RER values for ashes (3.49 and 14.09, respectively) and calcium (3.57 and 12.70, respectively) are good enough for screening. RPD and RER values for DF (2.60 and 9.15, respectively) and RER values for magnesium (6.57) also enable rough screening. A poorer correlation was achieved for UA. We conclude that NIRS can help in common bean breeding research and quality evaluation.

First Report of Sida micrantha mosaic virus in Phaseolus vulgaris in Brazil.

Snap and common beans (Phaseolus vulgaris L.) are severely affected by Bean golden mosaic virus (BGMV) infection, so far the only begomovirus reported on these crops in Brazil (1). Samples of snap and common beans colonized by the whitefly Bemisia tabaci biotype B and displaying golden mosaic, chlorotic spots, and leaf distortion were collected in three production regions in Goiás State (Goianápolis, Luziânia, and Itaberaí) between 2003 and 2007. Total DNA extracted from leaf samples was used as template in PCR assays using universal primers targeting conserved regions of the DNA-A and DNA-B genomes (3). Begomovirus-specific amplicons were observed only with DNA template from symptomatic plants. Two single amplicons were observed for both genomic segments, indicating the presence of bipartite species in all samples. Sequence analysis of four isolates (named as GO-176, GO-260, GO-354, and GO-368) obtained from common bean samples indicated identity levels of approximately 95% with the DNA-A segment of BGMV (GenBank Accession No. FJ665283). However, the complete DNA-A sequence (GenBank Accession No. HM357459.1) of the GO-060 isolate (from a symptomatic snap bean plant collected in Goianápolis) displayed 76% identity with BGMV (GenBank Accession No. FJ665283) and 95% identity with the DNA-A of a Sida micrantha mosaic virus (SimMV) isolate (GenBank Accession No. EU908733.1) reported to be infecting okra (Abelmoschus esculentus L.) and 94.8% with a SimMV isolate reported to be infecting soybean (GenBank Accession No. FJ686693) in Brazil (2). Koch's postulates were fulfilled for the isolate GO-060 by inoculating a set of soybean and bean accessions via a biolistic approach. The ratio of positive PCR amplicons per total of inoculated plants were 15 of 16 for snap bean cv. Trepador, 9 of 10 for snap bean cv. Fartura, 18 of 24 for common bean cv. Olate Pinto, and 19 of 25 for common bean cv. Carioca. The isolate was also able to infect eight of nine soybean 'Doko' plants. Sequence analysis using symptomatic leaf samples (15 days after inoculation) confirmed SimMV as the causal agent. To our knowledge, this is the first report of a SimMV isolate infecting P. vulgaris. This virus is apparently fast expanding its host range from Malvaceae to Solanaceae species and leguminous hosts after the introduction of B. tabaci biotype B (2). More extensive surveys are necessary to access the current epidemiological importance of SimMV in both snap and common beans in Brazil.

KINETIC OF WATER ADSORPTION IN COMMON BEAN: CONSIDERATIONS ON THE SUITABILITY OF PELEG'S MODEL FOR DESCRIBING BEAN HYDRATION

Water uptake of common bean samples belonging to both commercial cultivars and Italian local varieties and representing different market classes was studied. Three hydration groups characterized by slow, intermediate and fast water uptake were identified. Predictive efficacy of Peleg model, commonly used to describe legume soaking, was evaluated by analyzing data relative to samples belonging to the three hydration groups. It was observed that different hydration rate gave rise to significant variation of both Peleg constants within as well as among the groups. Moreover, the Peleg model predicted adequately only the hydration kinetic of common bean samples belonging to the fast hydration group. PRACTICAL APPLICATIONS Common bean is a worldwide crop, but it is underutilized because of long soaking and cooking times needed to achieve required digestibility. Because water absorption by seeds is the first step to prepare dishes based on legumes, there is interest in obtaining mathematical models to describe this process. As diffusional models are complex and cumbersome, empirical equations, such as Peleg's model, are commonly used to fit water absorption data of different food materials. This note shows as Peleg's model, which describes efficaciously the hydration of several legume species, is not able to always fit the water absorption data of common bean. This suggests the necessity for further studies aimed to the establishment of alternative mathematical models that are able to adequately describe water absorption kinetic in common bean.

The polyphenolic profiles of common bean ( Phaseolus vulgaris L.)

Based on the phenolic profiles obtained by high performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-DAD-ESI/MS), 24 common bean samples, representing 17 varieties and 7 generic off-the-shelf items, belonging to ten US commercial market classes can be organized into six different groups. All of them contained the same hydroxycinnaminic acids, but the flavonoid components showed distinct differences. Black beans contained primarily the 3- O-glucosides of delphinidin, petunidin and malvidin, while pinto beans contained kaempferol and its 3- O-glycosides. Light red kidney bean contained traces of quercetin 3- O-glucoside and its malonates, but pink and dark red kidney beans contained the diglycosides of quercetin and kaempferol. Small red beans contained kaempferol 3- O-glucoside and pelargonidin 3- O-glucoside, while no flavonoids were detected in alubia, cranberry, great northern, and navy beans. This is the first report of the tentative identification of quercetin 3- O-pentosylhexoside and flavonoid glucoside malonates, and the first detailed detection of hydroxycinnamates, in common beans.

Founder effect, plant host, and recombination shape the emergent population of begomoviruses that cause the tomato yellow leaf curl disease in the Mediterranean basin

Tomato yellow leaf curl disease (TYLCD)-associated viruses present a highly structured population in the western Mediterranean basin, depending on host, geographical region and time. About 1,900 tomato and common bean samples were analyzed from which 111 isolates were characterized genetically based on a genome sequence that comprises coding and non-coding regions. Isolates of three distinct begomoviruses previously described were found ( Tomato yellow leaf curl virus, TYLCV, Tomato yellow leaf curl Sardinia virus, TYLCSV, and Tomato yellow leaf curl Málaga virus, TYLCMalV), together with a novel recombinant virus. Mixed infections were detected in single plants, rationalizing the occurrence of recombinants. Except for TYLCV-type strain, single, undifferentiated subpopulations were present for each virus type, probably the result of founder effects. Limited genetic variation was observed in genomic regions, with selection against amino acid change in coding regions.

Perspectives into factors limiting in vivo digestion of legume proteins: antinutritional compounds or storage proteins?

The in vivo protein digestibility of raw and cooked common bean (Phaseolus vulgaris L.) and faba bean (Vicia faba L.) and of protein fractions extracted from them was determined with growing rats. Overnight-fasted rats were intubated with a protein suspension or fed the same amount of protein added to a basal diet. The rats were killed 1 h later, the contents of stomach and small intestine were washed out, and their protein contents were measured. The in vivo digestibility of proteins of raw common bean flour was 72.4% and not significantly improved after cooking. In contrast, the digestibility of faba bean proteins was decreased from 86.5 to 60.6% by the thermal treatment. Globulins from either species had similar digestibilities (approximately 70%). Proteins in the soluble fraction of cooked beans were more digestible than those in the insoluble fraction, which contained the bulk of the proteins. Hemagglutination assay and trypsin inhibitor determination indicated that after the thermal treatment only very low, nonharmful, levels of both lectin and inhibitor remained. Faba bean contained more polyphenols than common bean samples, with most of the polyphenols being bound to globulins. However, protein-bound polyphenols were markedly decreased after cooking. SDS-PAGE characterization of the gastrointestinal digesta of globulins and amino acid analysis of undigested proteins of whole cooked common bean and faba bean suggested that it is mainly the structural properties of the storage proteins and not their binding of polyphenols, which determines the extent of protein aggregation on autoclaving and may therefore be responsible for their low digestibility.

New Developments in Capillary Electrophoresis. Application of Capillary Electrophoresis to Quantitative Analysis and Characterization. Determination of betaine aldehyde in plants by Low-pH capillary electrophoresis.

A simple and rapid determination method for betaine aldehyde in plants was developed by capillary electrophoresis (CE). After betaine aldehyde was converted to the stable p-nitrobenzyl oxime, the reaction mixture was applied directly to CE. A low pH of around 3 of the migration buffer, which lowers the electroosmotic flow, was found to be favorable for the migration of positively charged compounds. This resulted in a high separation not only between the oximes, but also between the reagent and products. This also gave another advantage of omitting a pretreatment procedure of the reaction mixture. Betaine aldehyde oxime was well determined by either 214 or 270 nm within 15 minutes. A good linearity was shown in concentrations ranging from 0.10 to 10.0 mM. The repeatability (n=5) of the migration time and the peak area were 1.11 % and 5.62% as RSD, respectively. The method was applied to barley and common bean samples cultured with or without salt-stress, and proved to be suitable for the determination of a trace and unstable constituent, betaine aldehyde.