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To better understand the role that dietary fibre plays in the health benefits of pulses, the cell wall polysaccharides of pulses were characterized. To allow comparison between this data and nutritional studies, cooked chickpeas, lentils, beans and peas were used rather than raw seeds. Insoluble fibre, soluble fibre, resistant starch and oligosaccharide fractions were isolated using digestive enzymes at 37 °C. Prebiotic galacto-oligosaccharides, including raffinose, stachyose and verbascose made up between 3.5 and 6.9% of the cooked pulses (dry weight basis). Pulse fibre is pectin rich, with most being found in the soluble fibre fraction. The soluble fibre fraction is a diverse mixture of polysaccharides of varying sizes and solutions of soluble fibre exhibit a range of viscosities depending on the pulse type. The sugars which make up the insoluble fibre fraction suggest a large cellulose component. Microscopic examination of cooked whole pulses showed that a large fraction of the starch was partially gelatinized and contained within intact cell walls whereas boiled flour pastes had few ungelatinized granules. After simulated upper-gut digestion, some starch remained inaccessible to digestive enzymes. Cell walls of pulses modulate starch gelatinization and reduce enzymatic hydrolysis, which may account for the low glycemic response attributed to pulses. [ABSTRACT FROM AUTHOR]

Abstract: The physicochemical and functional properties of protein concentrates from peas, lentils, navy beans, chickpeas, and defatted chickpeas were investigated. Protein concentrates were prepared using a laboratory wet milling procedure. Chemical composition and colour of the protein concentrates were significantly different among the various pulses. Functional properties of the chickpea protein concentrates, including water hydration capacity, foaming capacity, and emulsion capacity, were improved significantly after a defatting step was added prior to the fractionation process. Navy bean protein concentrate had the largest foaming capacity, whilst chickpea protein concentrates had the smallest. Protein concentrates from lentils had the most stable foams after 120min, whilst those from chickpeas had the least stable foams. Navy bean protein concentrate also had the highest emulsion capacity, whilst pea protein concentrates had the poorest. Protein content of the protein concentrates was positively correlated, whilst the fat content was negatively correlated with foaming capacity (r=0.663, p<0.001 and r=−0.712, p<0.001, respectively). Water hydration capacity of the protein concentrates was significantly correlated with ash content (r=0.597, p<0.01), fat absorption (r=0.535, p<0.01), foaming capacity (r=0.775, p<0.001) and foam stability at 120min (r=0.595, p<0.01). Ash content and foaming capacity were significantly correlated with emulsion capacity (r=0.497, p<0.05, and r=0.552, p<0.01, respectively). [Copyright &y& Elsevier]

Abstract: The emulsifying (emulsion capacity, EC; emulsion activity/stability indices, EAI–ESI and creaming stability, CS) and physicochemical properties (surface charge/hydrophobicity, protein solubility, interfacial tension, and droplet size) of chickpea (ChPI), faba bean (FbPI), lentil (LPI), and pea (PPI) protein isolates produced by isoelectric precipitation and salt extraction were investigated relative to each other and a soy protein isolate (SPI). Both the legume source and method of isolate production showed significant effects on the emulsifying and physicochemical properties of the proteins tested. All legume proteins carried a net negative charge at neutral pH, and had surface hydrophobicity values ranging between 53.0 and 84.8 (H0-ANS), with PPI showing the highest value. Isoelectric precipitation resulted in isolates with higher surface charge and solubility compared to those produced via salt extraction. The EC values ranged between 476 and 542g oil/g protein with LPI showing the highest capacity. Isoelectric-precipitated ChPI and LPI had relatively high surface charges (~−22.3mV) and formed emulsions with smaller droplet sizes (~1.6μm), they also displayed high EAI (~46.2m2/g), ESI (~84.9min) and CS (98.6%) results, which were comparable to the SPI. [Copyright &y& Elsevier]

Abstract: Pulses are rich in nutrients. The existence of anti-nutritional components and the length of time required for preparation have, however, limited their frequency of use compared to recommended intake levels. Anti-nutritional components in pulses can be largely removed by heat treatment. Additionally pre-treatment of pulses with heat and processing of seeds into flour could further enhance their use by decreasing processing and preparation times. In this study, trypsin inhibitor activity, functional properties, and microstructural characteristics of flours prepared from different varieties of lentil, chickpea, and pea as affected by roasting and boiling were evaluated. Both thermal treatments resulted in significant reduction (p <0.05) in trypsin inhibitor activity ranging from −95.6% to −37.8%. Scanning electron microscopy (SEM) results showed that the roasted pulse flours had similar microstructure (i.e., starch granule and protein matrix structure) to the raw samples. For the pre-boiled flours, amorphous flakes were observed by SEM with no presence of intact starch granules. This is likely due to gelatinization of starch during cooking. Interestingly, flours treated by boiling exhibited significantly higher (p <0.05) fat binding capacity, water holding capacity, and gelling capacity, while protein solubility was significantly reduced compared to the raw and roasted pulse flours. Overall, thermal treatments either had no impact or impacted to different extents the emulsifying and foaming properties of the flours. Our results suggest that thermally-treated pulse flours may have very good potential to be used as value-added food ingredients for food applications due to their improved nutritional value and, in some instances, superior functionality. [Copyright &y& Elsevier]

Abstract: The physicochemical and functional properties of the fibre fractions from peas (Pisum sativum), lentils (Lens culinaris), chickpeas (Cicer arietinum L.) and navy beans (Phaseolus vulgaris) were evaluated, and the relationships amongst those properties were determined. Fibre fractions from several varieties of each species were prepared using a laboratory wet milling procedure. The fibre fractions contained 663.2 to 808.5g/kg DM of total dietary fibre, 45.4 to 171.1g/kg DM of crude protein, 102.7 to 195.6g/kg DM of starch and 1.9 to 10.5g/kg DM of crude fat. Fibre fractions from pea and kabuli chickpea displayed significant higher fat absorption (FA) than those from lentil, navy bean and desi chickpea. Lentil and navy bean fibre fractions exhibited larger mean particle size than did pea and chickpea fibre fractions. Pulse fibre fractions exhibited significantly higher water hydration, swelling and water retention capacities in comparison to commercial pea fibre products. A significant reverse relationship (r=−0.956, p<0.001) between mean particle size and specific surface area (SpSA) of pulse fibre fractions was observed. FA of fibre fractions was positively correlated with SpSA (r=0.820, p<0.001). [Copyright &y& Elsevier]

Abstract: In this study, two methods, isoelectric precipitation (IEP) and ultrafiltration (UF) were optimised for the extraction of proteins from yellow pea, desi and kabuli chickpeas, red and green lentils. For IEP, the following optimal extraction conditions were used: pH 9.5, 1/15 solid/liquid ratio, 35°C for yellow pea, desi and kabuli chickpeas, and pH 9.0, 1/10 solid/liquid ratio, 25°C for red and green lentils. UF experiments were performed with a 50kDa MWCO membrane with diafiltration (4X) at pH 6.0. The initial protein content of the pulses (16.7–24.8%, w/w) was concentrated nearly 4-fold. UF process generated concentrates with slightly higher protein contents (69.1–88.6%, w/w) compared to the IEP process (63.9–81.7%, w/w). Yields for both processes on a protein basis ranged from 50.3% to 69.1% (w/w). All concentrates exhibited good functional properties. However, functional properties varied to some extent as a function of the type of pulse and manufacturing process. For pH ranging from 1 to 3 and from 7 to 10, the red and green lentil concentrates were the most soluble (70–77%) and their UF concentrates were more soluble at all pH values studied compared to the IEP samples which was not the case for the pea and chickpea samples. Water holding capacity was highest for IEP-processed yellow pea and lowest for the UF-processed desi and kabuli chickpeas. Emulsifying properties and foam expansion were generally higher for the chickpea concentrates but they had less foam stability. Protein extracts from green lentils appeared to have the best gelling properties. The results highlight the technological potential of pulse protein extracts for food applications. [Copyright &y& Elsevier]

Abstract: Pulses are a good source of dietary fibre and other important nutrients. Flours and fibre-rich fractions obtained from pulse crops can be incorporated into processed foods to increase dietary fibre content and/or serve as functional ingredients. This review focuses on research conducted in the past ten years on the non-starch polysaccharides and oligosaccharides found in dry beans (Phaseolus vulgaris), chickpeas (Cicer arietinum), lentils (Lens culinaris), and dry peas (Pisum sativum). The isolation, composition, and structure of these pulse fibres are described. Common terms used to describe the physicochemical properties of fibre fractions are defined and briefly discussed. Recent studies on the effects of processing on the ratio of insoluble to soluble dietary fibre and on the α-galacto-oligosaccharide content of pulses and fibre fractions are cited and summarized. Food applications for pulse fibre fractions and flours in fibre enrichment, nutrient enrichment, fat binding and retention, and texture modification, as well as some non-food applications, are reviewed. [Copyright &y& Elsevier]

Legumes are a well-known source of phytochemicals and are commonly believed to have similar composition between different genera. To date, there are no studies evaluating changes in legumes to discover those compounds that help to discriminate for food quality and authenticity. The aim of this work was to characterize and make a comparative analysis of the composition of bioactive compounds between Cicer arietinum L. (chickpea), Lens culinaris L. (lentil) and Phaseolus vulgaris L. (white bean) through an LC-MS-Orbitrap metabolomic approach to establish which compounds discriminate between the three studied legumes. Untargeted metabolomic analysis was carried out by LC-MS-Orbitrap from extracts of freeze-dried legumes prepared from pre-cooked canned legumes. The metabolomic data treatment and statistical analysis were realized by using MAIT R's package, and final identification and characterization was done using MSn experiments. Fold-change evaluation was made through Metaboanalyst 4.0. Results showed 43 identified and characterized compounds displaying differences between the three legumes. Polyphenols, mainly flavonol and flavanol compounds, were the main group with 30 identified compounds, followed by α-galactosides (n = 5). Fatty acyls, prenol lipids, a nucleoside and organic compounds were also characterized. The fold-change analysis showed flavanols as the wider class of discriminative compounds of lentils compared to the other legumes; prenol lipids and eucomic acids were the most discriminative compounds of beans versus other legumes and several phenolic acids (such as primeveroside salycilic), kaempferol derivatives, coumesterol and α-galactosides were the most discriminative compounds of chickpeas. This study highlights the applicability of metabolomics for evaluating which are the characteristic compounds of the different legumes. In addition, it describes the future application of metabolomics as tool for the quality control of foods and authentication of different kinds of legumes. Unlabelled Image • LC-MS untargeted metabolomics to compare lentils, beans and chickpeas metabolome. • Six classes of compounds were statistically different between evaluated legumes. • Flavanol compounds were the most discriminant compounds of lentils. • Eucomic acid derivatives and prenol lipids were the most discriminant compounds of beans. • Several classes of compounds discriminate chickpeas from the other two legumes. [ABSTRACT FROM AUTHOR]