Oligosaccharides in raw and processed legumes

 Oligosaccharides from several types of raw and processed legume seeds consumed in Spain, e.g. lentils (Lens culinaris L.), chickpeas (Cicer arietinum L.), red kidney beans (Phaseolus vulgaris L.), white common beans (Phaseolus vulgaris L.), “Judiones de la Granja” great white beans (Phaseolus vulgaris L.) and faba beans (Vicia faba L.), were analysed by high performance liquid chromatography. The total sugar content ranged from 6.69% to 9.99%, and oligosaccharides represented 25–46% of the total sugar, in the various dry legumes. The main oligosaccharide in raw faba beans was verbascose (3.32%), and stachyose in the remaining legumes (2.21–3.23%). Different amounts of sucrose and traces of glucose, fructose and small amounts of inulin were present in raw samples of all the legumes. After soaking in tap water the loss of oligosaccharides was lowest in red beans (1.25%) and highest in common white beans (27.6%). Pressure cooking, without previous soaking, resulted in no oligosaccharide loss in common white beans but a loss of up to 32% in chickpeas. After pressure cooking of soaked legumes, the loss of stachyose ranged from 14.2% in red beans up to 35.9% for lentils. Substantial amounts of flatus-producing factors can be eliminated by common processing methods. Received: 12 May 1997 / Revised version: 17 July 1997     

Oligosaccharides in raw and processed legumes

 Oligosaccharides from several types of raw and processed legume seeds consumed in Spain, e.g. lentils (Lens culinaris L.), chickpeas (Cicer arietinum L.), red kidney beans (Phaseolus vulgaris L.), white common beans (Phaseolus vulgaris L.), “Judiones de la Granja” great white beans (Phaseolus vulgaris L.) and faba beans (Vicia faba L.), were analysed by high performance liquid chromatography. The total sugar content ranged from 6.69% to 9.99%, and oligosaccharides represented 25–46% of the total sugar, in the various dry legumes. The main oligosaccharide in raw faba beans was verbascose (3.32%), and stachyose in the remaining legumes (2.21–3.23%). Different amounts of sucrose and traces of glucose, fructose and small amounts of inulin were present in raw samples of all the legumes. After soaking in tap water the loss of oligosaccharides was lowest in red beans (1.25%) and highest in common white beans (27.6%). Pressure cooking, without previous soaking, resulted in no oligosaccharide loss in common white beans but a loss of up to 32% in chickpeas. After pressure cooking of soaked legumes, the loss of stachyose ranged from 14.2% in red beans up to 35.9% for lentils. Substantial amounts of flatus-producing factors can be eliminated by common processing methods. Received: 12 May 1997 / Revised version: 17 July 1997     

Bioaccessibility of calcium, iron and zinc from three legume samples

Legumes can be a source of mineral elements but also of antinutritional factors which can affect their absorption. An in vitro method including gastrointestinal digestion was used to estimate mineral bioavailability. Soluble (bioaccessible) and insoluble calcium, iron and zinc from white beans, chickpeas and lentils were determined after gastrointestinal digestion. The influence of the original sample weight on the soluble mineral fraction was also estimated. The results obtained show that white beans are the legumes with the highest bioaccessible calcium and iron contents. Lentils have a high iron content but its bioaccessibility is much lower than that of iron from white beans and chickpeas. An increase in sample weight increases the amount of bioaccessible element available for intake, but the increase is not always proportional.     

Classification of Lentils,Chickpeas and Beans Based on Their Isoflavone Content

Food legumes (Fabaceae) form an important part of the human diet; besides, several Fabaceae species are acknowledged for their high levels of bioactive compounds, among which are isoflavones, being recognised for their varied types of biological activity. The aim of this work was to classify different varieties of three types of legumes (chickpeas, lentils and beans) according to their isoflavone contents. The analysis of isoflavones was carried out using high-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (HPLC-MS/MS). To extract the analytes, a modified QuEChERS approach was used. The chromatographic peak areas obtained, after scaling in Pareto mode, were used to build statistical models. Both supervised and unsupervised techniques were applied for the classification of the different types of pulses analysed in the study: principal component analysis (PCA), hierarchical cluster analysis (HCA) and partial least squares discriminant analysis (PLS-DA). The statistical models were validated by internal validation, obtaining satisfactory results for the different matrices. PCA models allowed the differentiation between subspecies, but not subspecies, varieties or ecotypes. The results provided by HCA and PLS-DA revealed that the different species and subspecies of beans and the different varieties and subvarieties of lentils can be distinguished, and even the different ecotypes of the same variety in the case of chickpeas. This study revealed that it was possible to differentiate among species, subspecies, varieties and even ecotypes of different types of legumes based on their isoflavone content.     

豆类种子及萌发过程中功效性成分研究概述

豆类种子及其萌发后形成的芽苗菜富含多种生物活性成分,本文综述近几年有关大豆、绿豆、红小豆、蚕豆、豌豆等多种豆类种子及其萌发过程中酚类、大豆异黄酮、γ-氨基丁酸和左旋多巴等功能性成分的研究,分别从结构与种类、植物体内合成途径、保健功能和代谢过程中的变化规律等方面对这些功能成分进行了综述,为豆类芽苗菜功能保健产品开发提供理论借鉴与技术参考。     

The effects of hydrothermal processing on antinutrients, protein and starch digestibility of food legumes

The effects of hydrothermal processing on antinutrients and the protein and starch digestibility of black grams, chick peas, lentils and red and white kidney beans was investigated. The tannins and phytic acid contents in these five food legumes ranged from 770 to 1100 and 970 to 1440 mg/100 g, respectively, whereas protein and starch digestibility of the raw food legumes was found to be from 33.8 to 37.6 and 36.8 to 42.0%, respectively. A reduction in the level of these antinutrients, along with an improvement in protein and starch digestibility, was observed after cooking. The tannins and phytic acid contents were reduced by 33.1–45.7 and 28.0–51.6%, respectively, because of the use of different hydrothermal treatments at 100, 121 and 128 °C. Maximum improvement in protein digestibility (95.7–105.1%) and starch digestibility (116.7–137.7%) was observed on cooking at 121 °C for 10 min. However, cooking in boiling water resulted in improvement in protein and starch digestibility of the food legumes by 86.9–93.3 and 84.0–90.4%, respectively.     

Sword bean (Canavalia gladiata) as a source of antioxidant phenolics

Sword beans (Canavalia gladiata) have been used as grain legumes and medicinal plants in China for thousands of years. To explore new natural antioxidant sources, the antioxidant capacity and phenolic composition in the soluble and bound fractions of three sword bean genotypes were evaluated in vitro. The red and black sword beans were found to have antioxidant capacity compared to the white sword bean, and this was attributed to their red and black bean coats, which possessed extremely high phenolic content. Gallic acid and its derivatives, such as methyl gallate, digalloyl hexoside and digallic acid, were the main phenolic compounds in the coats of red and black sword beans. Therefore, the red and black sword beans, especially their bean coats, are good sources of antioxidant phenolics and may have potential health benefits.     

Phenolic Antioxidants in Some Vigna Species of Legumes and their Distinct Inhibitory Effects on α-Glucosidase and Pancreatic Lipase Activities

Phenolic extracts of 4 Vigna species of legumes (mung bean, moth bean, and black and red varieties of adzuki beans) were evaluated for phenolic contents, antioxidant activities, and inhibitory properties against α-glucosidase and pancreatic lipase. Results showed that adzuki bean varieties contain higher phenolic indexes than mung bean and moth beans. Adzuki bean (black) variety was found to be the most active 2,2′-diphenyl-1-picrylhydrazyl and superoxide anion scavenger. However, the hydrogen peroxide scavenging and metal chelating abilities were significantly higher in adzuki bean (red) variety. Mung bean exhibited least antioxidant activities in all the methods tested. Phenolic extracts from these legumes also showed distinct variations in the inhibition of enzymes associated with hyperglycemia and hyperlipidemia. Inhibitory activities of all the extracts against lipase were found to be more potent than α-glucosidase. Although, α-glucosidase inhibitory activity was superior in the black variety of adzuki bean (IC(50,) 26.28 mg/mL), both adzuki bean varieties (black and red) along with moth bean showed strong inhibitory activities on lipase with no significant difference in their IC(50) values (7.32 to 9.85 mg/mL). These results suggest that Vigna species of legumes are potential source of antioxidant phenolics and also great sources of strong natural inhibitors for α-glucosidase and lipase activities. This information may help for effective utilization of these legumes as functional food ingredients for promoting health. Practical Application: Vigna species of legumes are good sources of phenolic antioxidants and strong natural inhibitors of enzymes associated with diabetes and obesity. Therefore, utilization of these legumes in the development of functional foods with increased therapeutic value would be a significant step toward health promotion and wellness.     

Proximate Composition of Triangular Pea,White Pea,Spotted Colored Pea,and Small White Kidney Bean and Their Starch Properties

Physicochemical properties of beans and starches extracted from triangular pea, white pea, spotted colored pea, and small white kidney bean grown in China were investigated. Results pointed out that each of the different legumes might be a good resource of starch and protein, which could be utilized for specific applications in food processing. Starches separated from different legumes differed significantly with respect to their protein content, amylose/amylopectin ratio, lipid content, ash content, swelling power, and solubility. The scanning electron micrographs revealed the presence of kidney or elliptical- to irregular-shaped granules and with a diameter ranging from 5 to 40 μm. All starches exhibited a C-type X-ray diffraction pattern. The pasting properties were tested in a Rapid Visco Analyser and thermal properties with a differential scanning calorimeter. Small white kidney bean had the highest peak, trough, breakdown, and final viscosity among various starches. Triangular pea starch showed the highest gelatinization transition temperatures (T _o, T _p, and T _c) and enthalpy of gelatinization, while white pea starch showed the lowest transition temperatures and gelatinization enthalpy. The results obtained provide a technical basis for processing these legumes and starches.     

Fermentation alters antioxidant capacity and polyphenol distribution in selected edible legumes

This study was designed to investigate the influences of fermentation by naturally occurring bacteria on legumes and lactic acid bacteria on antioxidant capacity and polyphenols in both soluble and bound extracts of eight common edible legumes, including black cow gram, mottled cowpea, speckled kidney bean, lentil, small rice bean, small runner bean and two soya beans. Fermentation had varying effects on the antioxidant capacity of soluble and bound extracts in different edible legumes, with fermented mottled cowpea, speckled kidney bean and small rice bean showing increased total antioxidant capacity. In addition, fermentation in general enhanced total phenolic content in all the selected legumes, which could be associated with the biotransformation between soluble phenolics and the release of bound phenolics induced by micro‐organisms involved in the fermentation process. Phenolic compounds, such as catechin, were increased in fermented mottled cowpea. Overall, fermentation could increase the bioavailability of legume polyphenols and fermented legume powders rich in antioxidant polyphenols can be used to develop novel functional foods.     

The effect of multi-mineral mix (Fe,Zn, Ca and Cu) on magnesium binding to starchy legumes under simulated gastrointestinal conditions

The present in vitro study on starchy legumes and their Mg bioavailability, covers the factors: cooking, dietary fibre, phytic acid and the competitive binding of other minerals. Mg-binding capacity of food legumes (butter beans, broad beans and lentils) in the raw, cooked and fibre-rich fraction (FRF) forms with Mg addition alone and with Ca, Fe, Zn and Cu (at concentrations based on the recommended daily allowance) was investigated in conditions simulating the small intestine. The three legumes in the raw and cooked forms showed more significant (P<0.01) Mg-binding when Mg was added with Ca, Fe, Zn and Cu than with Mg addition alone. The FRFs were found to bind significantly (P<0.01) more Mg than the raw and cooked forms. Cooking significantly decreased (P<0.01) the Mg-binding capacity of raw butter beans, broad beans and lentils at separate Mg addition or with Ca, Fe, Zn and Cu.     

Isolation and Partial Characterization of Starches from Dry Beans (Phaseolus vulgaris) and Chickpeas (Cicer arietinum), Grown in Sonora,Mexico

For a better understanding of the carbohydrate components of Mexican dry legumes, in an attempt to suggest alternative processing, starches from dry beans (Phaseolus vulgaris var. pinto) and chickpeas (Cicer arietinum var. surutato) were isolated through sedimentation procedure. They were further characterized in their: physical characteristics of shape and size by light and Scanning Electron Microscopy (SEM); chemical characteristics by proximate analyses and amylose contents; functional characteristics of gelatinization temperature, viscosity and thermal properties by Differential Scanning Calorimetry (DSC); and nutritional characteristics, % digestibility. Starch in these two legumes was firstly isolated at over 85% recovery, with an amylose content of 52.4% and 46.5% for dry beans and chickpeas, respectively. SEM and light microscopy showed starch granules with a predominantly oval shape and size in the range of 20–25μ, for both legumes. Higher gelatinization temperatures were found for dry beans than for chickpeas. Similarly, fusion enthalpies and maximum gelatinization temperature were also higher for beans, as shown by DSC. However, chickpea starch gave a slightly higher % digestibility than bean starch. These results suggested that the difference in the amylose content, in both legumes, determine the starch granule structure, their intermolecular organization and their physical and functional characteristics.     

Thermal heat processing effects on antinutrients,protein and starch digestibility of food legumes

Thermal heat processing effects were investigated on antinutrients, protein and, starch digestibility of black grams, chick peas, lentils, red and white kidney beans. The tannin and phytic acid contents in these five food legumes ranged from 770–1100 mg/100 g to 970–1440 mg/100 g, respectively, whereas protein and starch digestibilities of the raw food legumes were 33.0–37.6% and 36.8–42.0%, respectively. Reduction in the levels of antinutrients, along with an improvement in protein and starch digestibility, was observed after cooking these food legumes. Antinutrient, including tannin (33.1–45.7%) and phytic acid (28.0–51.6%) contents, were reduced by different thermal heat treatments (121AC10, 121AC20, 121AC40, 121AC60, 121AC90, 128AC20). Maximum improvement in protein (95.7–105%) and starch (117–138%) digestibilities was observed on cooking these food legumes at 121 °C for 10 min (121AC10). However, ordinary cooking resulted in improvement of protein and starch digestibilities of the food legumes by 86.0–93.3% and 84.0–90.4%, respectively.     

Simplified Enzymatic-gravimetric Method for Total Dietary Fiber In Legumes Compared with a Modified AOAC Method

Two methods (an AOAC and a simplified enzymatic-gravimetric method) were used to analyze seven types of canned legumes and eight cooked legumes. Total dietary fiber (TDF) of the canned products ranged between 17% and 23% (dry basis) for chick peas, Great Northern beans, kidney beans, pinto beans, pork & beans, vegetarian beans in tomato sauce, and 27–31% for wax beans. These values were comparable for both methods. However, results on cooked legumes were very different between methods. TDF values for several types of beans and peas were higher and ranged between 31% and 5.5% by the AOAC/Tris-Mes buffer method as compared to 17% and 29% using the simplified method. Chemical analysis of dietary fiber residues showed the major difference between the methods was in the extent of starch removal as affected by starch gelatinization.     

FACTORS AFFECTING THE COOKING QUALITY OF FIELD PEAS (PISUM SATIVUM L.) AND WHITE BEANS (PHASEOLUS VULGARIS L.) STORED UNDER SIMULATED FARM CONDITIONS

Factors affecting the cooking, physical, chemical, and biological characteristics of field peas and white beans were studied after 147 days’ storage under northern temperate climatic conditions. Cooking time, hydration and swelling characteristics, phytate levels, fat acidity values (FAV), off-odor and visible mold development were assessed. Among the different initial moisture contents and storage temperature regimens investigated, only the highest temperature regimen (44C declining to 15C) was associated with a noticeable reduction in the cooking quality of peas and beans. Although a gradual decline was seen in the hydration and swelling characteristics of both legumes, and in phytate levels of peas stored at the 44C to 15C regimen, no single factor appeared to explain the changes in cooking quality of peas and beans stored at high temperatures. Correlation analyses indicated the association of high levels of conductivity and FAV with poor hydration characteristics and off-odor development in the two legumes.     

Composition of underexploited Indian pulses. Comparison with common legumes

There is increasing interest in finding new food sources to alleviate malnutrition in developing countries. Moth beans and horse gram are two underexploited Indian legumes growing in adverse conditions but their composition is little-known. Total and resistant starch (RS), dietary fibre (DF) and soluble sugars including oligosaccharides were determined, along with protein, fat, ash and polyphenols. They were compared with other legumes common in Asian and Western countries: black gram, green gram, haricot beans and chickpeas. No apparent differences among the proximate compositions were observed. All samples were rich in DF (18–31% d.m.), made mainly of insoluble DF, whilst RS varied between 3.4 and 8.3%. Oligosaccharides were the main soluble sugars in all legumes; haricot beans and chickpeas were rich in sucrose. All legumes had a high content of non-digestible carbohydrates (37–48% of carbohydrates). In summary, from the composition study, moth beans and horse gram are of a good nutritional quality, making them suitable for more extensive uses.     

Subtilisin inhibitors in Canavalia and Vicia faba seeds. A comparative study

Subtilisin isoinhibitors (SI) were isolated from jack bean (Canavalia ensiformis L) and broad bean (Vicia faba L) seeds. Jack beans contain three isoinhibitors (pI 6.6, 6.3 and 6.0) that constitute 0.021 g per 100 g of dry seeds, while the two active proteins from broad beans (pI 5.7 and 5.1) represent 0.028%. The molecular weight, determined by gel filtration, is around 8000 D in both legumes. Large variations in specific activity of SI against subtilisin Carlsberg were detected in six species of the Canavalia genus, whereas only slight changes were found among six cultivars of C ensiformis. Antibodies raised against SI isolated from jack beans are specific for SI from different varieties of this and other species of the Canavalia genus. However, they do not recognise SI from broad beans and other legume seeds tested. In broad beans the variability between cultivars is significant. Cv Canaria has two active bands and four are detected in the ?dark’? variety, which is 2.7 times less active than the former. SI are specific towards microbial serine proteases, showing high affinity for proteinase K. No appreciable activity against animal proteases or plant thiol enzymes can be detected. SI are also inactive against 4 alpha-amylases of different origins. Reversible limited proteolysis of the reactive site bond suggests that SI interact with subtilisin by the ?standard mechanism’? usually accepted for the inhibition of trypsin by its proteinaceous inhibitors.     

贵州不同品种芸豆营养品质差异分析

探究大白芸豆、红芸豆、黑花芸豆、红腰豆和中白芸豆主要营养成分含量差异,对其营养品质进行分析与评价。以5个芸豆品种为试验材料,测定芸豆的蛋白质、脂肪、淀粉、灰分、矿物质元素、氨基酸和脂肪酸含量。结果表明:供试芸豆的蛋白质、脂肪、淀粉和灰分含量品种间差异极显著（P<0.01）,其含量分别为17.30~23.70、1.10~1.90、34.90~38.30、4.00~4.80 g/100 g。中白芸豆蛋白质和淀粉含量最高,分别为23.70、38.30 g/100 g;黑花芸豆K、Ca、Na和Mg含量最高,分别为1.99×104、1.15×103、33.40、1.79×103 mg/kg,中白芸豆Fe和Zn含量最高,分别为77.10、41.80 mg/kg,中白芸豆Na含量最低,为25.40 mg/kg;氨基酸含量范围是0.08~3.75 g/100 g,中白芸豆必需氨基酸（EAA）、非必需氨基酸（NEAA）和总氨基酸（TAA）含量最高,分别为8.86、14.17、23.03 g/100 g;5种芸豆脂肪酸含量范围是0.0020~0.8913 g/100 g,含有16种脂肪酸,其中饱和脂肪酸有9种,单不饱和脂肪酸有3种,多不饱和脂肪酸有4种,其含量排序依次为多不饱和脂肪酸>饱和脂肪酸>单不饱和脂肪酸,大白芸豆脂肪酸含量最高,为2.02 g/100 g。中白芸豆多不饱和脂肪酸与饱和脂肪酸比率（PS）最低,数值为4.14,红腰豆动脉粥硬化指数（AI）值最低,数值为0.005。综合多种营养成分含量分析,中白芸豆营养品质优于大白芸豆、红芸豆、黑花芸豆、红腰豆。     

Optimization of iron speciation (soluble,ferrous and ferric) in beans,chickpeas and lentils

A spectrophotometric method with bathophenanthroline for iron determination that makes it possible to differentiate between iron (II) and iron (III) in total soluble iron in legumes (beans, chickpeas and lentils) was optimized. Sample size, volumes of reducing agent and bathophenanthroline were selected. Matrix interferences made it necessary to apply the addition’s method. To check the quality of the method, linearity and precision (RSD%) were determined. A linear response between 0.1 and 1.8 μg Fe/ml in the assay and precision values ranging from 2.1 to 6 for instrumental precision, and from 1.6 to 1.7 and 2.7 to 9.1, for intra- and inter-day assays, respectively were obtained. The application of the method to legumes indicated: total soluble iron ranging from 0.52 (microwave cooked legumes) to 5.01 mg/100 g dry matter in raw beans. The percentage of soluble iron (II) with respect to total and soluble iron ranged from non detectable to 14.8% and from non detectable to 50%, respectively.     

Production of enterotoxin A and thermonuclease by Staphylococcus aureus in legumes

Growth, enterotoxin A (SEA) and thermonuclease (TNase) production of S. aureus (Strains CP 7 and FRI 722) was determined in media produced from the following heat or irradiation sterilized legumes: peas, black beans, mung beans, adzuki beans and soybeans. Media containing the five legumes alone or in combination with Brain Heart Infusion Broth (BHI) were tested. With the exception of heat-sterilized black beans and adzuki beans, S. aureus growth was excellent in all media with cell counts after 48 h (25 °C) exceeding 10⁸ cfu/ml. In black beans and adzuki beans cell counts were 1–2 log-cycles lower. Enterotoxin A was produced in amounts of 33 to 72 ng/ml in BHI after 48 h. Almost no toxin was produced in the four different beans following heat or irradiation treatment; in peas the toxin concentration reached 14 to 15 ng/ml. In the medium prepared from irradiated soybeans and BHI the final toxin concentration was about the same as in BHI alone. In all the other media consisting of a combination of legumes with BHI toxin concentrations were there to four times higher than in BHI alone. Production of thermonuclease showed variation and did not always correlate with enterotoxin production.