Biochemistry and technology of chickpea (Cicer arietinum L.) seeds

Chickpea is an important source of proteins, carbohydrates, B-group vitamins, and certain minerals, particularly to the populations of developing nations. India contributes over 75% of the chickpea production in the world where it is mostly consumed as dhal, whole seeds, and several types of traditional, fermented, deep fried, sweetened, and puffed products. In this review, the world production and distribution, genetic background, biochemical and nutritional quality, and developments in storage and processing technology of chickpea are discussed. Future research needs, to improve the utilization of chickpea as human food, are addressed.     

Protein quality of chickpea (Cicer arietinum L.) protein hydrolysates

Chickpea protein isolate (CPI) was used as the starting material in the production of chickpea protein hydrolysates (CPHs). To obtain a highly extensive hydrolysate with a degree of hydrolysis higher than 50%, a sequential utilisation of endoprotease (Alcalase) and exoprotease (Flavourzyme) was necessary. Molecular weight patterns of CPHs were determined by gel filtration chromatography. As a result of the enzymatic activity, differences in the chromatographic pattern of CPHs were observed. Although significant (P⩽0.05) decreases of Phe and Arg were observed after hydrolysis, adequate amounts of essential amino acids in relation to the reference pattern of FAO (FAO/WHO/ONU, 1985. Energy and requirements. Technical report series No. 724. Geneva) were found. In vitro protein digestibility of CPHs (95%) were similar to that of the starting material (CPI), and TIA was not detected in any case. A high increase of solubility in CPHs, with respect to CPI, was observed, one CPH being totally soluble over a wide pH range (2–10) when the enzymes were added sequentially. Due to their high protein quality and solubility, CPHs might be considered as potential ingredients in the food industry.     

Milling and physicochemical properties of chickpea (Cicer arietinum L.) varieties

BACKGROUND: Physical characteristics of chickpea (Cicer arietinum L.) seeds such as grain size, weight and hull content are important from a milling and marketing point of view. Chemical characteristics provide the information on nutritional status of grains. Chickpea of Desi (cv. A1) and Kabuli (cv. L550) cultivars were analyzed for their physicochemical, milling and milled flour quality characteristics. RESULTS: Between dry and wet milling, higher yield of dhal was obtained from wet milling, which was found to be true in both cultivars. An extra yield of 2–4% was obtained in wet milling. Between the cultivars, Desi was found to be the higher dhal‐yielding cultivar in both dry and wet milling methods. Fat, ash and protein contents were found to be higher in Kabuli than in Desi and the values were respectively 5.3%, 3.5% and 24.9% for Kabuli and 4.3%, 2.2% and 22.6% for Desi. CONCLUSION: The chickpea cultivars Desi and Kabuli vary significantly in their physical properties such as seed color, size, 100‐seed weight and 100‐seed volume. Between the dry and wet milling, a higher yield (2–4%) of dhal was obtained from wet milling. Between the cultivars, electronic nose analysis of chickpea flour indicated the possibility of differentiating the variations associated with varietal difference and milling. The gel electrophoresis pattern of chickpea showed as many as 15 protein bands in flours from both the cultivars, either in phosphate or SDS buffer. The Rapid Visco Analyzer profile did not show a significant difference between the two cultivars. Copyright © 2008 Society of Chemical Industry     

Genotype and growing environment influence chickpea (Cicer arietinum L.) seed composition

BACKGROUND: As a first step towards genetic improvement of seed quality in chickpea (Cicer arietinum L.), seven desi and nine kabuli varieties were grown at multiple sites to assess the affect of environment on seed yield, weight and selected seed constituents. The sites were chosen to represent a range of environments in chickpea production areas of the Canadian prairies. RESULTS: Genotype × environment interaction effects on starch, amylose and protein (desi only) concentrations and seed yield were significant, suggesting that the varieties did not perform consistently relative to each other in the different environments. Starch concentration was negatively correlated (r_kabuli = ?0.25, P < 0.05; r_desi = ?0.16, P < 0.05) with protein concentration in both chickpea market classes. However, repeatability estimates of starch, amylose and protein concentrations were low and inconsistent across chickpea market classes, possibly owing to complex biosynthetic pathways for these constituents. CONCLUSION: The results suggest that testing for seed constituent traits over a range of environments will be required to improve seed quality in individual chickpea varieties. The best selection strategies for seed constituent improvement in chickpea will be influenced by genotype and genotype × environment interaction for these traits. The negative relationship between seed constituents and yield indicates that selection for chickpea cultivars with desired seed composition may require compromise and indirect selection. Copyright © 2009 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.     

Hypocholesterolaemic and antioxidant activities of chickpea (Cicer arietinum L.) protein hydrolysates

BACKGROUND: Some dietary proteins possess biological properties which make them potential ingredients of functional or health‐promoting foods. Many of these properties are attributed to bioactive peptides that can be released by controlled hydrolysis using exogenous proteases. The aim of this work was to test the improvement of hypocholesterolaemic and antioxidant activities of chickpea protein isolate by means of hydrolysis with alcalase and flavourzyme. RESULTS: All hydrolysates tested exhibited better hypocholesterolaemic activity when compared with chickpea protein isolate. The highest cholesterol micellar solubility inhibition (50%) was found after 60 min of treatment with alcalase followed by 30 min of hydrolysis with flavourzyme. To test antioxidant activity of chickpea proteins three methods were used: β‐carotene bleaching method, reducing power and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical‐scavenging effect since antioxidant activity of protein hydrolysates may not be attributed to a single mechanism. Chickpea hydrolysates showed better antioxidant activity in all assays, especially reducing power and DPPH scavenging effect than chickpea protein isolate. CONCLUSION: The results of this study showed the good potential of chickpea protein hydrolysates as bioactive ingredients. The highest bioactive properties could be obtained by selecting the type of proteases and the hydrolysis time. Copyright © 2012 Society of Chemical Industry     

Intrinsic variability of mineral composition of chickpea (Cicer arietinum,L.)

The influence of genetic biotype on the mineral composition of chickpea was studied. Experimental design included 37 cultivars of both Desi and Kabuli biotypes cultivated under the same climatic and agronomic conditions in order to exclude the variability of the results due to environment and genotype × environment interaction effects. The biotype, as source of variance in mineral composition, was a significant factor in explaining differences between Ca, Mg and K contents. Cu, Fe, Mn, Na and Zn contents did not show differences between biotypes. According to data previously published, differences may be explained by differences in the coat thickness and composition between biotypes. Two homogeneous subgroups of chickpea cultivars were identified, one having relatively high calcium contents and the other having relatively high iron contents.     

Polar lipids of defatted chickpea (Cicer arietinum L.) flour and protein isolates

Polar lipid composition of defatted chickpea flour and protein isolates was studied. The main compounds were phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine. Other compounds, in lower amounts, were sterol glucosides, esterified sterol glucosides and digalactosyldiglycerides. Palmitic, oleic and linoleic acid were the main fatty acids in polar lipids. A reduction in the content of phosphatidylinositol and sterol glucosides in the protein isolates with respect to the defatted flour was observed, indicating that these compounds are more sensitive to the chemical treatment of the protein isolates. However, unsaturated fatty acids and unsaturated sterols content decreased in the protein isolates probably undergoing oxidative degradation.     

Empirical and diffusion models to describe water transport into chickpea (Cicer arietinum L.)

To describe water transport in a porous media, a mathematical model is usually used. Among the models available in the literature, empirical and diffusive ones can be cited. In this paper, Page and diffusion models are used to describe drying and soaking of chickpea. In addition, new empirical equation is proposed to describe the mentioned processes. According to the results, the two empirical models well describe drying and soaking, but the proposed one gives the best statistical indicators. The use of the diffusion model to describe the drying process makes it possible to determine the effective diffusivities (7.13 × 10^?11, 10.39 × 10^?11 and 13.78 × 10^?11 m² s^?1 for the drying air at 40, 50 and 60 °C, respectively) and also the activation energy associated with the process (27.9 kJ mol^?1).     

Evaluation of rapid methods for the estimation of protein in chickpea (Cicer arietinum L.)

Protein content in chickpea (Cicer arietinum L.) was determined by the following rapid procedures: (a) colorimetric estimation of ammonia with phenol-hypochlorite reagents using the Technicon auto-analyzer (TAA) method, (b) dye-binding capacity (DBC) method using acid orange-12 dye, and (c) modified biuret methods of Pinckney (B1) and Johnson and Craney (B2). Results obtained with the above procedures were compared statistically with the standard microKjeldahl (MKJ) procedure. Correlation of MKJ protein values with TAA, DBC, B1 and B2 methods were 0.99, 0.98, 0.96 and 0.95, respectively. Standard errors of estimation obtained by methods B1 (0.99) and B2 (0.95) were high when compared to the TAA (0.55) and DBC (0.69) methods. Possible interference of seed-coat pigments, effect of flour particle size, and time of shaking on protein estimation by the DBC and B1 methods were also studied. Implications of these results are discussed with reference to adapting any of these rapid methods as a routine screening procedure for the estimation of protein in large numbers of chickpea samples in a breeding programme.     

Protein isolates from chickpea (Cicer arietinum L.): chemical composition,functional properties and protein characterization

Two types of protein isolates were prepared from ground chickpea seeds by alkaline extraction, with (Isolate-B) and without (Isolate-A) sodium sulphite, and acid precipitation of the proteins at the isoelectric point (pI 4.3). The percentage of protein recovered from chickpea flour in the preparation of Isolates-A and B were 65.9 and 62.1%, respectively. Chemical composition, main functional properties and protein composition of chickpea flour and protein isolates were determined. Isolates-A and B contained 78 and 88.1% of protein, respectively, and had a balanced content of essential amino acids, with respect to the FAO pattern. The in vitro protein digestibility ranged between 95.6 and 96.1%. Isolate-A showed a partial dissociation of the 11S protein because of the high pH used for the protein extraction, and this probably explains the differences observed in the functional characteristics of both isolates.     

Composition and properties of starches from Virginia‐grown kabuli chickpea (Cicer arietinum L.) cultivars

Composition and properties of seeds and starches from five Virginia‐grown kabuli chickpea cultivars were investigated. The seeds had the average weight of 4.48 g per 10 g and volume of 641.2 mm³, and were rich in carbohydrate with starch as a principal constituent (59.2–70.9%). Resistant starch accounted for 7.7–10.4% of the total starch content. The composition and properties of the starches among the five cultivars were significantly different (P ≤ 0.05). All starches had a C‐type crystalline structure. The degree of crystallinity ranged from 21.1% to 27.4%, gelatinisation temperature from 7.97 to 11.2 °C and gelatinisation enthalpies from 2.18 to 3.76 J g^?1, and water absorption capacities from 90.7% to 117.5%. Different shapes and granule sizes were observed. Molecular weight of amylopectin was in the range of 6.35 × 10⁸–11.6 × 10⁸ Da. Cultivar ‘HB‐14’ was superior to the other cultivars, when combining larger seed size, higher resistant starch level and better properties.     

Characterization of chickpea (Cicer arietinum L.) flours and application in low-fat pork bologna as a model system

The suitability of chickpea grown in Western-Canada was studied in a low-fat (fat <5%) emulsion-type meat product as a model. Six high-yielding chickpea varieties were screened and one Kabuli and Desi variety were selected for testing in a meat system. The physiochemical, textural and sensory properties of low-fat pork bologna extended with chickpea flour (or pea and wheat flour as comparisons) at 2.5% and 5.0% were investigated. Inclusion of chickpea flour improved the product’s instrumental and sensory texture properties. Bologna with added Kabuli and Desi chickpea flour performed similar to the control (no added binder) for most flavour properties. However, panelists noted more foreign-flavours with addition of wheat and pea flour at 5.0%. This study shows that chickpea flour is a potential source of high protein flour for use as an extender in emulsified meat products due to its superior technological functionality and minimal effects on flavour.     

The use of hydrogen peroxide for the digestion and determination of total nitrogen in chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan L.)

The use of hydrogen peroxide as an alternative to catalysts in the determination of nitrogen in plant materials has been investigated. Nitrogen determination in leaf, stem and seed samples of chickpea and pigeonpea was carried out by three digestion procedures, using hydrogen peroxide (H₂O₂ digestion) without a catalyst, and with mercury or selenium as catalysts (catalyst digestions). The nitrogen values obtained by the three digestion procedures did not differ significantly from each other when examined by microKjeldahl (MKJ) using mercury as a catalyst, and by a Technicon auto analyser (TAA) using selenium as catalyst. The gradual addition of H₂O₂, as recommended previously, was found to be unnecessary. In view of the cost and health hazards implicated with the use of mercury and selenium for digestion, the procedure based on H₂O₂ digestion is preferable for large scale N determinations in plant tissue and seed samples of these pulse crops. The results sugest that the H₂O₂ digestion technique can be conveniently adapted for total N analysis in plant tissues and grain samples by either TAA or MKJ method.     

Interaction of the human intestinal microbiota with the release of bound phenolic compounds in chickpea (Cicer arietinum L.)

The objective of this work was to release bound phenolic compounds (PC) from chickpea by the interaction of the microbiota of a volunteer and to identify the enzymes implied to deliver these PC. The highest amount of PC was released at 12 and 24 h (16.8–18.5 mg GAE/g). Higher antioxidant capacity was observed in these hours through 2,20-azino-bis-(3ethylbenzothiazoline-6-sulfonic acid), 2,2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power and 2,´2.Azobis (2 methylpropionamidine) techniques. Escherichia, Klebsiella, Bacteroides and Veillonella were some genera identified in the microbiota implied in delivered PC. The principal PC identified by ultra performance liquid chromatography–mass spectrometry were flavonoids. Proteomic analysis identified hundreds of proteins from the intestinal microbiota after 12 h of fermentation, including enzymes related to the release of bound PC from chickpea such as pectin esterase. Therefore, this enzyme could be used in other food sources for the release of PC bound to the food matrix and thus take advantage of their bioactive benefits.     

Functional Properties of Drum-Dried Chickpea (Cicer arietinum L.) Flours

The chemical and functional properties of three precooked flours pre-pared from citric acid- and sodium bicarbonate-treated chickpeas were compared with those of raw chickpea and soybean flours. The nitrogen solubility and foaming capacity of the precooked flours were markedly reduced by processing. The acid-treated flours showed higher values of oil absorption and viscosity than the sodium bicarbonate-treated flour, but the latter had a higher bulk density. Even at 10% concentration, the acid-treated flour slurries manifested very low viscosities (about 11 centipoises). No significant difference was detected in the water absorption and gelation capacity of the precooked flours.     

Kinetics of roasting of split chickpea (Cicer arietinum)

The effects of three roasting temperatures on rates of moisture loss, size reduction and increase in bulk density in roasting chickpea dhal in a small rotary roaster mostly followed first order kinetics. Electrical energy use was more efficient at 150 than 125 or 100°C.     

Study of selected quality and agronomic characteristics and their interrelationship in Kabuli‐type chickpea genotypes (Cicer arietinum L.)

Impact of genotype on quality, agronomic characteristics and their interrelationship in Kabuli‐type chickpea was investigated to provide significant feedback to breeder for selection/evolution of the most suitable varieties. Seven genotypes were studied for seventeen physical, chemical and agronomic characteristics. The effect of Kabuli‐type chickpea genotype on the physicochemical parameters, cooking time and agronomic characteristics were significant. Maximum seed size and volume were recorded for CC98/99 (0.32 g and 0.26 mL seed^?1, respectively), density and swelling index for the genotype FLIP97‐179C (having minimum seed size and volume), while the rest of the genotypes were statistically the same. Weight, volume after hydration, hydration capacity and swelling capacity followed the same pattern. Maximum moisture, protein and mineral concentration were noted in CC98/99. Seed protein concentration for the remaining genotypes was statistically non‐significant from one another. Longer period was taken by CM 2000 for flowering and maturity (130 and 181 days, respectively). Minimum time to flowering and maturity was taken by CC98/99. Genotype CC 98/99 outyielded all other genotypes (2107 kg ha^?1). Seed size and seed volume were strongly and positively correlated with protein content, weight after hydration, volume after hydration, hydration and swelling capacities (r = 0.83–1.0). Strong correlation was also noted among different agronomic characters.