Effect of germination and dehulling on functional properties of legume flours

The functional properties of flours derived from selected legumes were studied before and after dehulling of the germinated seeds. Ungerminated seeds were used as the control. The chosen legumes were green gram (Phaseolus aureus), cowpea (Vigna catjang), lentil (Lens culinaris) and bengal gram (Cicer arietinum). Dehulled samples had a higher protein solubility compared with germinated and control samples. The bulk densities of germinated and dehulled legume flours were lower compared to control. Germination increased water absorption capacities of legume flours from 1226, 1285, 974 and 1362 g kg^?1 to 1481, 1433, 1448 and 1517 g kg^?1 in green gram, cowpea, lentil and bengal gram, respectively. Fat absorption capacities increased in germinated samples (1130, 1242, 920 and 837 g kg^?1) as against 900, 993, 857 and 788 g kg^?1 at ambient conditions for green gram, cowpea, lentil and bengal gram, respectively. On dehulling, the fat absorption capacities of samples were reduced and the differences were statistically significant. The emulsification capacities of control samples ranged from 55 to 193 ml oil emulsified per gram of sample. On germination and dehulling, the emulsification capacities, activities and stabilities of samples increased significantly. There were increases in foaming capacities and reduction in foam stabilities of all the samples investigated on germination and dehulling. Thus, the study indicated that germination and dehulling improved the functional properties of legumes. Copyright © 2006 Society of Chemical Industry     

Effect of different legume seeds on life table parameters of cowpea weevil,Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae)

The cowpea weevil, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) is one of the most important storage pests of legume seeds. The effect of various legume species including chickpea (Cicer arietinum L.) (cultivars Hashem and Mansour), cowpea (Vigna unguiculata L.) (cultivars Mashhad and 1057), green gram (Vigna radiata L.) (cultivar Parto), lentil (Lens culinaris Medikus) (cultivar Bilehsavar) was studied on the life history and life table parameters of C. maculatus at 30 ± 1 °C, relative humidity of 65 ± 5% and complete darkness. The developmental time was longest on lentil and shortest on cowpea 1057. The fecundity (number of eggs laid per reproductive period) of the pest was the lowest on lentil. The longest oviposition period was observed on chickpea Hashem. The gross and net reproductive rates were the highest on chickpea Mansour and lowest on lentil. The intrinsic rate of increase and finite rate of increase were the lowest when C. maculatus was reared on lentil and highest when it was reared on other hosts. The longest and shortest mean generation times were observed on lentil and cowpea 1057, respectively. According to the obtained results, lentil was relatively resistant and the other tested legumes were more susceptible hosts for feeding and population increase of C. maculatus. It is concluded that the resistant host cultivar can be proposed to be incorporated into breeding programs to minimize the economic losses incurred by C. maculatus.     

Nutrients and antinutrients in cowpea and horse gram flours in comparison to chickpea flour: Evaluation of their flour functionality

The nutrient composition, antinutritional factors and flour functionality of cowpea and horse gram flours were evaluated in comparison to chickpea flour characteristics. Protein content of these flours was in the range of 22.5−24.1%. Fat content was highest in chickpea (4.8%) and lowest in horse gram (1.4%). Resistant starch and phytic acid were significantly higher in cowpea flour. Compared to chickpea and cowpea, horse gram has more carbohydrate, dietary fibre, polyphenols and trypsin inhibitor activity and less oligosaccharides. Horse gram and chickpea flours had the highest water and oil absorption capacities with values of 148.1% and 109.3%, respectively. Although emulsion activity (58.1%) and stability (52.0%) were superior in horse gram, foaming capacity and foam stability were significantly higher in chickpea and cowpea flours, respectively. These results suggest the potential utility of cowpea and horse gram flours as substitutes for chickpea flour in some food products formulations.     

Antinutrients (phytic acid,polyphenols) and minerals (Ca,Fe) availability (in vitro) of chickpea and lentil cultivars

High yielding cultivars of chickpea (Desi and Kabuli) (Cicer arietinum) and lentil (Lens esculenta) were analysed for their total mineral content, per cent availability (in vitro) of minerals and level of antinutrients. Gora Hisari (Kabuli chickpea), Haryana channa (Desi chickpea) and La-12 (lentil) were found superior. These cultivars contain highest per cent availability (in vitro) of calcium and iron and lowest values of phytic acid and polyphenols compared to other cultivan of chickpea and lentil.     

Carbohydrate composition of raw and extruded pulse flours

Extrusion cooking technology is commercially used in the fabrication of a variety of snack-type and ready-to-eat foods made from cereal grains. However, with the exception of soybean, pulses such as lentil, dry pea and chickpea have not been used for the development of extruded food products. In this study, total carbohydrates, mono-, di- and oligosaccharides, and soluble and insoluble dietary fiber were determined before and after extrusion cooking under specific processing conditions. Concentrations of total available carbohydrates (TAC) in lentil, chickpea and dry pea flours ranged from 625 g/kg to 657 g/kg dry matter. Dry pea showed the highest concentration of TAC, followed by chickpea and lentil. Extrusion processing did not significantly (p < 0.05) affect the TAC content of dry pea and lentil flours. However, extrusion processing decreased the concentration of the raffinose family of oligosaccharides (raffinose and stachyose) in pulse extrudates. Formulated pulse flours demonstrated a beneficial increase in dietary fiber. This research indicates that value-added, nutritious snacks with reduced levels of flatulence factors and higher contents of dietary fiber can be fabricated successfully by extrusion processing of formulations based on lentil, dry pea or chickpea, and represent good alternatives to traditional cereal-based snacks. Also, the commercialization of value-added, pulse-based snacks would increase pulse consumption.     

Sensory and Physicochemical Studies of Thermally Micronized Chickpea (Cicer arietinum) and Green Lentil (Lens culinaris) Flours as Binders in Low‐Fat Beef Burgers

Pulses are known to be nutritious foods but are susceptible to oxidation due to the reaction of lipoxygenase (LOX) with linolenic and linoleic acids which can lead to off flavors caused by the formation of volatile organic compounds (VOCs). Infrared micronization at 130 and 150 °C was investigated as a heat treatment to determine its effect on LOX activity and VOCs of chickpea and green lentil flour. The pulse flours were added to low‐fat beef burgers at 6% and measured for consumer acceptability and physicochemical properties. Micronization at 130 °C significantly decreased LOX activity for both flours. The lentil flour micronized at 150 °C showed a further significant decrease in LOX activity similar to that of the chickpea flour at 150 °C. The lowering of VOCs was accomplished more successfully with micronization at 130 °C for chickpea flour while micronization at 150 °C for the green lentil flour was more effective. Micronization minimally affected the characteristic fatty acid content in each flour but significantly increased omega‐3 and n‐6 fatty acids at 150 °C in burgers with lentil and chickpea flours, respectively. Burgers with green lentil flour micronized at 130 and 150 °C, and chickpea flour micronized at 150 °C were positively associated with acceptability. Micronization did not affect the shear force and cooking losses of the burgers made with both flours. Formulation of low‐fat beef burgers containing 6% micronized gluten‐free binder made from lentil and chickpea flour is possible based on favorable results for physicochemical properties and consumer acceptability.     

Influence of sprouting on phenolic composition and starch characteristics of lentil and horse gram

Effect of sprouting on the content of different phenolic compounds and starch characteristics of horse gram was compared to that of lentil. Increase in gallic acid, p-coumaric acid and ferulic chlorogenic acid content was observed in horse gram and lentil, respectively, with sprouting. Luteolin content in basic-bound fraction increased in lentil and decreased in horse gram with sprouting. Lentil starches showed higher retrogradation tendency than horse gram starches. Storage modulus and retrogradation tendency of starch gels decreased initially followed by an increase after 96 h of sprouting. Horse gram starches showed higher crystallinity than lentil starches, and crystallinity increased with increase in sprouting period. Horse gram starches showed higher onset, peak and conclusion temperature than lentil starches. Transition temperatures decreased with increase in sprouting duration in both the pulses. Sprouting changed the crystalline structure of starch significantly as well as phenolic composition of both the pulses.     

Provitamin‐A and xanthophyll carotenoids in vegetables and food grains of nutritional and medicinal importance

This study reports carotenoid composition of vegetables (n = 56), cereals (n = 12), pulses and legumes (n = 12), analysed by HPLC. It was hypothesised that food grains, like vegetables may be good sources of carotenoids. Amongst vegetables, higher level (mg/100 g dry weight) of lutein (210–419) was detected in green/red/capsicum and yellow zucchini, whilst zeaxanthin was dominant in kenaf (4.59). β‐Carotene (mg/100 g dry weight) was higher in green capsicum and kenaf (48,159) whilst carrot, ivy gourd and green capsicum contain α‐carotene (22–110). Amongst food grains, chickpea, split red gram and flaxseed contain higher levels (μg/100 g dry weight) of lutein (185–200) whilst zeaxanthin level was highest in puffed chickpea (1.8). Red unpolished parboiled rice was richest (μg/100 g dry weight) in β‐carotene (67.6) whilst whole black gram contained higher levels of α‐carotene (52.7). Thus, results indicate that chickpea and red unpolished parboiled rice are good sources of carotenoids. These carotenoid‐rich vegetables and grains may be exploited to meet the lutein and β‐carotene requirement.     

Pectin and calcium chloride treatment for low‐fat fried green gram splits

Fried green gram (Phaseolus mungo L) splits are a traditional savoury relished by consumers of all age groups as an anytime snack. The high oil content in such products is of concern owing to its association with obesity and related health disorders. The present work evaluates the effect of soaking green gram splits in calcium chloride solution (2.5–10 g kg^?1) for 3 h followed by air drying and a subsequent dip in 10–30 g l^?1 pectin solution for 10 min, again followed by air drying, on the oil content in the fried product prepared from them. After frying in groundnut oil at 170 ± 5 °C for 2 min, the oil content in the pretreated fried product was reduced to 211.7 g kg^?1, compared with 335 g kg^?1 for the untreated control. Attempts to further reduce the oil content by applying a second coating of pectin were unsuccessful. Copyright © 2005 Society of Chemical Industry     

Chemical analysis and physico-chemical properties of chickpea and lentil cultivars

Some high yielding cultivars of chickpea (Kabuli and desi) (Cicer arietinum) and lentil (Lens esculenta) were used for chemical analysis and physico-chemical properties namely protein, fat, sugars, starch, in vitro digestibility of starch and protein; seed weight, seed volume, seed density, hydration capacity, swelling capacity, water absorption capacity and cooking time. Among chickpea, Gora Hisari (Kabuli) and Haryana Chana (desi) cultivars, and among lentil LH 82-6 cultivar manifested higher contents of protein, fat, sugars, starch and in vitro digestibility of starch and protein. Values of seed volume, seed density, hydration capacity, swelling capacity and water absorption capacity were also found higher for these cultivars which might have contributed towards less cooking time.     

Phytic acid content of chickpea (Cicer arietinum) and black gram (Vigna mungo): varietal differences and effect of domestic processing and cooking methods

Phytic acid content of various cultivars showed a narrow variation: 7.48-8.00 g kg^?1 and 6.47-6.68 g kg^?1 for chickpea (Cicer arietinum L) and black gram (Vigna mungo L), respectively. Phytic acid was lowered significantly by the common methods of domestic processing and cooking including soaking, cooking, autoclaving and sprouting of the legume grains. Sprouting had the most marked phytic acid lowering effect followed by autoclaving and soaking. Cooking of soaked seeds lowered phytic acid by 20-26% in chickpea and 35-40% in black gram grains whereas the loss was 7-11% and 6-9% in these pulses, respectively, when unsoaked seeds were cooked.     

Antioxidant properties of legumes and their morphological fractions as affected by cooking

The antioxidant properties of 6 legumes: green gram (Vigna radiate), red kidney beans (Phaseolus vulgaris), chickpea (Cicer arietinum), red lentil (Lens esculenta), soybean (Glycine max), and moth beans (V. aconitifolia), and their morphological fractions were evaluated before and after cooking. Kidney beans had the highest total phenolic content (8.9 mg ferulic acid equivalents/g), DPPH free radical scavenging activity (38.1%), reducing power (85.5 μmol ascorbic acid equivalents/g), and total flavonoid content (0.9 mg catechin equivalents/g). Highest metal chelating activity was observed for moth beans (93.3%). The antioxidant properties of the seed coat in all the legumes were manifold higher as compared to the whole legume or its respective endosperm and removal of the seed coat significantly reduced the antioxidant activity. Although cooking brought about a reduction in the antioxidant activity of the legumes in majority of the legumes and their fractions, an increase in the metal chelating activity was observed.     

Optimisation of microwave digestion for determination of Fe,Zn, Mn and Cu in various legumes by flame atomic absorption spectrometry

Fe, Zn, Mn and Cu levels in three Turkish legumes, kidney bean (Phaseolus vulgaris L.), lentil (Lens esculenta) and chickpea (Cicer arietinum), were determined by flame atomic absorption spectrometry. Dissolution conditions in the microwave‐assisted wet digestion method were studied by investigating several variables, including type of acid mixture, acid volume, digestion time, microwave power input and sample weight. Comparison with conventional wet acid digestion was also made. In order to check the element losses during digestion and the accuracy of the results, all tests were repeated after the addition of a spiked standard element solution to the legume sample. The microwave‐assisted digestion procedure optimised for kidney bean was adapted for lentil and chickpea. Fe, Zn, Mn and Cu concentrations (mg per 100 g sample) were determined in kidney bean as 6.27 ± 0.94, 2.23 ± 0.36, 1.64 ± 0.14 and 0.99 ± 0.19, in lentil as 8.24 ± 1.11, 2.46 ± 0.06, 1.17 ± 0.19 and 1.01 ± 0.28 and in chickpea as 6.00 ± 1.40, 2.21 ± 0.14, 1.60 ± 0.43 and 0.58 ± 0.18 respectively. Copyright © 2005 Society of Chemical Industry     

PROCESSING OF LEGUMES: RESISTANT STARCH AND DIETARY FIBER CONTENTS

Resistant starch (RS) and dietary fiber contents of differently processed Bengal gram (chickpea), black gram, green gram and red gram (pigeon pea) dhals were determined. In traditionally cooked dhals, RS increased 1.6 to 9 fold, whereas pressure cooked dhals showed a 2.1 to 8 fold increase over that of uncooked dhals. Deep fat frying of a black gram food product resulted in a 3 fold increase in RS. Germination of the whole legumes resulted in only a small increase in RS; but the content of insoluble dietary fiber was higher. Pressure‐cooking of red gram dhal in the presence of additives showed considerable variation in the yield recovery of RS. Lactic acid and ascorbic acid, added after cooking, enhanced (>100%) RS; addition of hydrocolloids had only marginal effects; whereas addition of spice powder before cooking lowered RS, an effect similar to the one observed upon addition of oils/lipids.     

In vitro starch digestibility,expected glycemic index,and thermal and pasting properties of flours from pea,lentil and chickpea cultivars

In vitro starch digestibility, expected glycemic index (eGI), and thermal and pasting properties of flours from pea, lentil and chickpea grown in Canada under identical environmental conditions were investigated. The protein content and gelatinization transition temperatures of lentil flour were higher than those of pea and chickpea flours. Chickpea flour showed a lower amylose content (10.8–13.5%) but higher free lipid content (6.5–7.1%) and amylose–lipid complex melting enthalpy (0.7–0.8 J/g). Significant differences among cultivars within the same species were observed with respect to swelling power, gelatinization properties, pasting properties and in vitro starch digestibility, especially chickpea flour from desi (Myles) and kabuli type (FLIP 97-101C and 97-Indian2-11). Lentil flour was hydrolyzed more slowly and to a lesser extent than pea and chickpea flours. The amount of slowly digestible starch (SDS) in chickpea flour was the highest among the pulse flours, but the resistant starch (RS) content was the lowest. The eGI of lentil flour was the lowest among the pulse flours.     

Effect of the addition of pulse ingredients to milk on acid production by probiotic and yoghurt starter cultures

Pulses contain carbohydrates, proteins, minerals and vitamins which are essential requirements in the human diet and which could also serve as growth nutrients for probiotic and yogurt starter cultures. In this study, milk supplementation with pulse ingredients is examined as a means to increase the nutritional properties of yogurt and probiotic type beverages. The acid production rate of two yogurt starters (A and B) and two probiotic cultures (Lactobacillus rhamnosus and Lactobacillus acidophilus) was followed in milk supplemented with the following soy and pulse ingredients: pea protein, chickpea flour, lentil flour, pea fibre, soy protein concentrate and soy flour. The pulse ingredients had no negative effect on the acidification trends of the fermented milks. On the contrary, with yogurt culture B, pea fibre, pea protein and lentil flour significantly enhanced the acidification rate. All ingredients used for supplementation improved the acidification rate of probiotic cultures, and the highest effects were obtained with lentil and soy flour. Lentil flour had the lowest pH after 12 h which was significantly lower than the product enriched with the same quantity of skim milk powder. The effect of ingredient supplementation on the microbial composition (ratio of cocci to bacilli) of the yoghurt products was also examined. The ratio of cocci to bacilli was between 1.8 and 2.5 for all supplemented yogurt samples obtained with culture A, and these variations were not judged to be statistically significant (p < 0.05). With yogurt products obtained from culture B, however, there was a higher proportional level of lactobacilli in all supplemented samples, as compared to the milk control; the enhanced growth of the lactobacilli was particularly noted when lentil flour was added to milk.     

Characterization of protein isolates from different Indian chickpea (Cicer arietinum L.) cultivars

Protein isolates prepared by alkaline solubilization followed by isoelectric precipitation and freeze drying from desi (PBG-1, PDG-4, PDG-3, GL-769, and GPF-2) and kabuli (L-550) chickpea cultivars were evaluated for functional (water and oil absorption capacities, least gelation concentration, foaming capacity and stability) and thermal properties. Significant difference (P ? 0.05) in properties of kabuli and desi chickpea protein isolates was observed. Kabuli chickpea protein isolate showed significantly (P ? 0.05) higher ash (1.14%), protein (94.4%), L^∗, ΔE value, oil absorption capacity (OAC) and lower water absorption capacity (WAC) than their corresponding desi chickpea protein isolates. The solubility-pH profile of different protein isolates showed minimum solubility in the pH between 4.0 and 5.0 and two regions of maximum solubility at pH 2.5 and 7.0. Foaming capacity of all protein isolates increased with the increase in concentration. Kabuli chickpea protein isolate showed the highest foam stability (94.7%) after 120 min of storage. The thermal properties of protein isolates from different chickpea cultivars were studied by differential scanning calorimetry (DSC). Protein isolates from both the chickpea types differed significantly (P ? 0.05) in peak denaturation temperature (T_d) and heat of transition (ΔH). Kabuli type protein isolate exhibited lower T_d and ΔH value as compared to those from desi types. The interrelationships between characteristics of protein isolates showed a significant (P ? 0.05) negative correlation of T_d with protein content and OAC. It was also observed that cultivars with high fat content had high ΔH and lower WAC.     

Efficacy of Some Essential Oils Against Aspergillus flavus with Special Reference to Lippia alba Oil an Inhibitor of Fungal Proliferation and Aflatoxin B1 Production in Green Gram Seeds during Storage

During mycofloral analysis of green gram (Vigna radiata (L.) R. Wilczek) seed samples taken from different grocery stores by agar and standard blotter paper methods, 5 fungal species were identified, of which Aspergillus flavus exhibited higher relative frequency (75.20% to 80.60%) and was found to produce aflatoxin B₁. On screening of 11 plant essential oils against this mycotoxigenic fungi, Lippia alba essential oil was found to be most effective and showed absolute inhibition of mycelia growth at 0.28 μL/mL. The oil of L. alba was fungistatic and fungicidal at 0.14 and 0.28 μL/mL, respectively. Oil had broad range of fungitoxicity at its MIC value and was absolutely inhibited the AFB1 production level at 2.0 μL/mL. Chemical analysis of this oil revealed geranial (36.9%) and neral (29.3%) as major components followed by myrcene (18.6%). Application of a dose of 80 μL/0.25 L air of Lippia oil in the storage system significantly inhibited the fungal proliferation and aflatoxin production without affecting the seed germination rate. By the virtue of fungicidal, antiaflatoxigenic nature and potent efficacy in storage food system, L. alba oil can be commercialized as botanical fungicide for the protection of green gram seeds during storage.     

Saponin content of chickpea and black gram: Varietal differences and effects of processing and cooking methods

Differences were observed in saponin contents of eight varieties of chickpea (Cicer arietinum) and four of black gram (Phaseolus mungo). Common domestic processing and cooking treatments reduced the saponin level of the pulses significantly. Sprouting had the most pronounced effect followed by autoclaving, soaking and ordinary cooking. Cooking of soaked as well as unsoaked seeds had a similar diminishing effect.