Effect of processing methods on nutrients and anti-nutritional factors in cowpea

Effect of different physical pre-treatments on physicochemical and techno-functional properties, and on the antinutritional factors of lentils (Lens culinaris spp)

Lentils have a valuable physicochemical profile, which can be affected by the presence of antinutrients that may impair the benefits arising from their consumption. Different treatments can be used to reduce these undesirable compounds, although they can also affect the general composition and behaviour of the lentils. Thus, the effect of different processing methods on the physicochemical and techno-functional properties, as well as on the antinutritional factors of different lentil varieties was studied. Phytic acid was eliminated during germination, while tannins and trypsin inhibitors are mostly affected by cooking. Functional properties were also altered by processing, these being dependent on the concentration of different nutrients in lentils. All the studied treatments affected the physicochemical profile of lentils and their functional properties. Cooking and germination appear to be the most effective in reducing antinutritional factors and improving the physicochemical profile of the lentils, meeting the current nutritional demands of today's society.

Effects of phytase-supplemented fermentation and household processing on the nutritional quality of Lathyrus sativus L. seeds

Grass pea (Lathyrus sativus L.) is commonly consumed in cooked, fermented, and roasted forms in Ethiopia. However, the impacts of household processing practices on its nutrients, antinutrients, and toxic compounds have not been adequately studied. Therefore, the effects of household processing and fermentation in the presence and absence of a phytase on the contents of β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), myo-inositol phosphates, crude protein, minerals and the in vitro bioaccessibility were investigated. Fermentation exhibited a significant decline in β-ODAP (13.0-62.0%) and phytate (7.3-90.5%) irrespective of the presence of phytase. Pressure and pan cooking after discarding the soaking water resulted in a 27.0 and 16.2% reduction in β-ODAP. A 30% reduction in phytate was observed during germination followed by roasting. In addition, germination resulted in a significant (p < 0.05) increase in crude protein. Germination and germination followed by roasting resulted in the highest Fe bioaccessibilities (more than 25 fold higher compared to untreated samples) followed by pressure cooking and soaking. Processing also improved Zn bioaccessibilities by 50.0% (soaked seed without soaking water), 22.5% (soaked seed with soaking water), and 4.3% (germination). Thus, the processing technologies applied were capable of reducing the content of phytate (InsP6) and β-ODAP with a concomitant increase in mineral bioaccessibilities. Processing of grass peas could therefore contribute to their more widespread utilization.

Two-Step Isolation, Purification, and Characterization of Lectin from Zihua Snap Bean (Phaseolus vulgaris) Seeds

A two-step method based on an aqueous two-phase system and Sephadex G-75 was used to separate and purify lectin from the seeds of the Zihua snap bean. The preliminary properties and bioactivity of the Zihua snap bean lectin were characterized by different instrumental methods, such as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE), liquid chromatography-nano electrospray ionization mass spectrometry (Nano LC-ESI-MS/MS), and Fourier transform infrared spectroscopy (FTIR). The hemagglutinating activity of the Zihua snap bean lectin could not be inhibited by glucose, N-acetyl-d-glucosamine, d-galactose, N-acetyl-d-galactosamine, fructose, sucrose, d-maltose, d-trehalose, and lactose. It was found that the hemagglutinating activity of the lectin showed strong dependence on Mn²⁺ and Ca²⁺. The thermal and pH stability of the Zihua snap bean lectin was studied by FTIR and fluorescence spectroscopy. Relatively good stability was observed when the temperature was not higher than 70 °C, as well as in the pH range of 2.0 to 10.0. Digestive stability in vitro was investigated. The untreated lectin was relatively stable to pepsin and trypsin activity, but heat treatment could significantly reduce the digestive stability in vitro. Moreover, the lectin showed an inhibitory effect on the tested bacteria (Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Bacillus subtilis (B. subtilis)), and it also showed a certain inhibitory effect on the growth of Phytophthora infestans (P. infestans) at higher concentrations.

An Update on Genetic Modification of Chickpea for Increased Yield and Stress Tolerance

Chickpea is a highly nutritious grain legume crop, widely appreciated as a health food, especially in the Indian subcontinent. The major constraints on chickpea production are biotic (Helicoverpa, bruchid, aphid, ascochyta) and abiotic (drought, heat, salt, cold) stresses, which reduce the yield by up to 90%. Various strategies like conventional breeding, molecular breeding, and modern plant breeding have been used to overcome these problems. Conventionally, breeding programs aim at development of varieties that combine maximum number of traits through inter-specific hybridization, wide hybridization, and hybridization involving more than two parents. Breeding is difficult in this crop because of its self-pollinating nature and limited genetic variation. Recent advances in in vitro culture and gene technologies offer unique opportunities to realize the full potential of chickpea production. However, as of date, no transgenic chickpea variety has been approved for cultivation in the world. In this review, we provide an update on the development of genetically modified chickpea plants, including those resistant to Helicoverpa armigera, Callosobruchus maculatus, Aphis craccivora, as well as to drought and salt stress. The genes utilized for development of resistance against pod borer, bruchid, aphid, drought, and salt tolerance, namely, Bt, alpha amylase inhibitor, ASAL, P5CSF129A, and P5CS, respectively, are discussed.

Cowpea: an overview on its nutritional facts and health benefits

Cowpea (Vigna unguiculata) is a legume consumed as a high-quality plant protein source in many parts of the world. High protein and carbohydrate contents with a relatively low fat content and a complementary amino acid pattern to that of cereal grains make cowpea an important nutritional food in the human diet. Cowpea has gained more attention recently from consumers and researchers worldwide as a result of its exerted health beneficial properties, including anti-diabetic, anti-cancer, anti-hyperlipidemic, anti-inflammatory and anti-hypertensive properties. Among the mechanisms that have been proposed in the prevention of chronic diseases, the most proven are attributed to the presence of compounds such as soluble and insoluble dietary fiber, phytochemicals, and proteins and peptides in cowpea. However, studies on the anti-cancer and anti-inflammatory properties of cowpea have produced conflicting results. Some studies support a protective effect of cowpea on the progression of cancer and inflammation, whereas others did not reveal any. Because there are only a few studies addressing health-related effects of cowpea consumption, further studies in this area are suggested. In addition, despite the reported favorable effects of cowpea on diabetes, hyperlipidemia and hypertension, a long-term epidemiological study investigating the association between cowpea consumption and diabetes, cardiovascular disease and cancer is also recommended. © 2018 Society of Chemical Industry.

Changes in levels of enzyme inhibitors during soaking and cooking for pulses available in Canada

The effects of processing (soaking and cooking) on enzyme inhibitors (α-amylase, trypsin and chymotrypsin inhibitors) in a range of pulses (4 peas, 9 lentils, 3 chickpeas, 2 faba beans and 4 beans) were investigated, using soybean as a control. Analysis of variance indicated that pulse type, treatment and their interaction had significant effects on levels of all enzyme inhibitors. Soybean contained the highest levels of trypsin inhibitory activity (TIA) and chymotrypsin inhibitory activity (CIA) among all seeds. α-Amylase inhibitory activity was absent from peas, lentils, chickpeas and faba beans, but was present in beans and soybean. TIA was found to be low in peas but high in beans. Beans contained relatively high CIA levels followed by chickpeas, lentils, peas and faba beans. Soaking markedly decreased the activity of enzyme inhibitors. Cooking of presoaked seeds was even more effective as greater reductions (78.7-100%) were observed for all pulses. The content of enzyme inhibitors in pulses varied widely, but levels of protease inhibitors were generally lower that those found in soybean. Processing, in particular heat treatments, drastically reduced these levels.

Effect of Replacing Soybean Meal by Raw or Extruded Pea Seeds on Growth Performance and Selected Physiological Parameters of the Ileum and Distal Colon of Pigs

The use of pea seeds is limited due to the content of antinutritional factors that may affect gut physiology. Heat treatment such as extrusion may reduce heat-labile antinutritional factors and improve the nutritional value of pea seeds. This study determined the effect of partial replacement of soybean meal in pig diets by raw or extruded pea seeds on growth performance, nitrogen balance and physiology of the ileum and distal colon. The experiment was carried out in 18 castrated male piglets of initial body weight of 11 kg, divided into three groups. The animals were fed cereal-based diets with soybean meal (C), which was partly replaced by raw (PR) or extruded pea (PE) seeds. Nitrogen balance was measured at about 15 kg body weight. After 26 days of feeding, tissue samples were taken from the ileum and distal colon for histological measurements, and colonic digesta samples for analyses of microbial activity indices. The animals fed the PE diet had a significantly greater average daily gain than those fed the C diet and better apparent protein digestibility than those on the PR diet. Pigs fed the PR diet had a significantly greater butyric acid concentration and lower pH in the colon than pigs fed PE and C diets. There was no significant effect of the diet on other indices of microbial activity or morphological parameters. In conclusion, feeding a diet with extruded pea seeds improved growth performance of pigs, did not affect intestinal morphology and had a negligible effect on microbial activity in the distal colon.

Effect of dehulling, germination and cooking on nutrients, anti-nutrients, fatty acid composition and antioxidant properties in lentil (Lens culinaris)

The changes in chemical composition, antioxidant activity and fatty acid composition of lentil flour after dehulling, germination and cooking of seeds were investigated. Dehulling showed no significant effect on protein content, however, protein content decreased in most of the varieties after germination and cooking. Total soluble sugars (TSS) content increased significantly after dehulling (2.0-41.64 %) and cooking (2.08-31.07 %) whereas, germination had no significant effect on TSS content. Total lipids increased significantly after dehulling (21.56-42.86 %) whereas, it decreased significantly after germination (2.97-26.52 %) and cooking (23.05-58.63 %). Cooking was more effective than other methods in reducing trypsin inhibitors (80.51-85.41 %). Dehulling was most effective in reducing tannins (89.46-92.99 %) and phytic acid (52.63-60.00 %) content over raw seed. Myristic, palmitic, stearic, oleic and linoleic acid content decreased while linolenic acid content increased after dehulling. Dehulling, germination and cooking decreased the content of antioxidant metabolite (gallic acid, catechin and quercetin) and also antioxidant activities. Raw samples followed by germinated samples showed the highest concentrations of phytochemicals responsible for antioxidant activity and also the antioxidant capacities. Present study showed germination and cooking would be useful in formulation and development of lentil based functional foods for human health benefits.

Quality evaluation of physical properties, antinutritional factors, and antioxidant activity of bread fortified with germinated horse gram (Dolichus uniflorus) flour

Horse gram was germinated at 90% RH at 25°C for 72 h after 24 h soaking and then grinded to pass through 150 μm mesh size screens. The germination of horse gram result in increased protein, fiber, total polyphenol content, and antioxidant activity of horse gram flour whereas fat, ash, carbohydrate, iron, calcium, tannin, phytate, and oxalate were reduced due to germination. Bread was prepared by the incorporation of (2%, 4%, 6%, and 8%) germinated horse gram flour (GHF) by a straight dough method. The loaf volume and specific volume decreased with an increased use of percentage of GHF. The sensory evaluation revealed that the incorporation of GHF up to 6% was acceptable. The protein (% db), fiber (% db), ash (% db), iron (mg/100 g), calcium (mg/100 g), tannin (mg/g), phytate (mg/g), oxalate (mg/g), total polyphenol content (GAE/g), and antioxidant activity (DPPH % inhibition) was found to be 9.08 ± 0.01, 1.23 ± 0.15, 1.36 ± 0.11, 4.07 ± 0.03, 128 ± 0.26, 2.06 ± 0.15, 2.46 ± 0.15, 0.7 ± 0.1, 12.44 ± 0.40, and 31.13 ± 0.25, respectively, in 6% GHF incorporated bread. The research concludes that 6% GHF incorporation in bread enhance the polyphenol content and antioxidant properties.

Cowpea (Vigna unguiculata L. Walp), a renewed multipurpose crop for a more sustainable agri-food system: nutritional advantages and constraints

The growing awareness of the relevance of food composition for human health has increased the interest of the inclusion of high proportions of fruits and vegetables in diets. To reach the objective of more balanced diets, an increased consumption of legumes, which constitutes a sustainable source of essential nutrients, particularly low-cost protein, is of special relevance. However, the consumption of legumes also entails some constraints that need to be addressed to avoid a deleterious impact on consumers' wellbeing and health. The value of legumes as a source of nutrients depends on a plethora of factors, including genetic characteristics, agro-climatic conditions, and postharvest management that modulate the dietary effect of edible seeds and vegetative material. Thus, more comprehensive information regarding composition, especially their nutritional and anti-nutritional compounds, digestibility, and alternative processing procedures is essential. These were the challenges to write this review, which focusses on the nutritional and anti-nutritional composition of Vigna unguiculata L. Walp, an emerging crop all over the world intended to provide a rational support for the development of valuable foods and feeds of increased commercial value. © 2016 Society of Chemical Industry.

Individualistic impact of unit operations of production, at household level, on some antinutritional factors in selected cowpea-based food products

The individualistic effect of unit operations of production, at household level, on some antinutritional factors in selected cowpea-based food products (moin-moin, akara, and gbegiri) was investigated. Four cowpea types (IT93K-452-1, IT95K-499s-35, IT97K-568-18, and market sample) were used for the study, whereas the three traditional food products were produced from each of the cowpea types, respectively. The results revealed that every unit operation involved in the production of moin-moin, akara or gbegiri contributed to the overall reduction of trypsin inhibitor activity (TIA), phytic acid (PA), and tannin; though at varying degrees. In the production of moin-moin, the major contributions to the overall reduction in TIA were from steaming (64.2-72.0%), second-stage soaking (9.7-11.9%), and dehulling (9.4-10.2%). The contributions to the overall reduction in PA were from dehulling (34.0-40.4%), preliminary soaking (15.4-21.0%), and steaming (7.8-14.0%), whereas that of tannin were from dehulling (39.7-47.6%), steaming (19.6-24.7%), and preliminary soaking (9.8-15.9%). For akara production, the major contributions to TIA reduction were from deep frying (64.2-72.0%), second-stage soaking (9.7-11.9%), and dehulling (9.4-10.2%). The PA reduction was from dehulling (34.0-40.4%), preliminary soaking (15.4-21.0%), and deep frying (9.6-15.9%), whereas that of tannin reduction was from dehulling (39.7-47.6%), deep frying (20.7-25.3%), and preliminary soaking (9.8-15.9%). In the production of gbegiri, the overall reduction in TIA was contributed from pressure cooking (79.0-84.8%), preliminary soaking (5.8-11.3%), and dehulling (9.4-10.2%). The reduction in PA was contributed by dehulling (34.0-40.4%), pressure cooking (24.7-35.0%), and preliminary soaking (15.4-21.0%), whereas the overall reduction in tannin content was similarly contributed by dehulling (39.7-47.6%), pressure cooking (29.8-34.4%), and preliminary soaking (9.8-15.9%).

Impact of dehulling and germination on nutrients, antinutrients, and antioxidant properties in horsegram

The changes in chemical composition, antioxidant activity and minerals content of horse gram seed after dehulling and germination of 12 advance lines were investigated. Dehulled samples had a higher protein content compared with the raw and germinated. Total soluble sugars (TSS) content increased significantly (p ≤ 0.05) after dehulling (29.31 %) and germination (98.73 %) whereas, the total lipids increased (10.98 %) significantly (p ≤ 0.05) after dehulling and decreased (36.41 %) significantly (p ≤ 0.05) after germination. Dehulling and germination significantly decreased the amount of phytic acid (PA), tannin (TN) and oxalic acid (OA). Trypsin inhibitor units decreased (26.79 %) significantly (p ≤ 0.05) after germination. The minerals (Ca, Fe and Cu) composition of the germinated horsegram flour samples was significantly higher than the raw and dehulled flour. The functional properties of flours were studied and found that the bulk density (11.85 %) and oil absorption capacity (18.92 %) significantly increased after germination. Raw samples followed by germinated samples showed the highest concentrations of phytochemicals responsible for the antioxidant activity and also the antioxidant capacities. principal component analysis revealed that in case of dehulled samples; TN, polyphenols, DPPH and ABTS radical inhibition, TSS, total antioxidant, OA, protein, FRAP value, Ca and Zn had positive correlation among themselves while in case of germinated samples, protein, oil absorption capacity, FRAP value, OA, total flavonoids, DPPH radical inhibition, Ca and Cu had positive correlation among themselves. Present study suggest that germination combined with dehulling process improved quality of horsegram by enhancing the nutritive value and reducing the antinutrients.

Microwave assisted dehulling of black gram (Vigna mungo L)

This article summarises the results of the investigation of application of microwave exposure on the dehulling characteristics of the black gram and the properties of the dehulled grains. Black gram was exposed to 3 microwave power levels, viz., 450, 630 and 810 W for 7 different exposure, ranging from 60 to 150 s at an interval of 15 s with a view to determine the suitable combination of dosage in order to get the maximum yield with little change in colour. Related changes in properties were also studied. It was observed that the surface temperature of the grain increased with the increase in microwave power level from 450 to 810 W as well as exposure time from 60 to 150 s in the range from 58 to 123 °C while the dehulling time reduced from 445 to 170 s. The dehulling yield increased with increasing microwave dosage in the beginning and reached to the maximum value followed by decreasing trend. The colour of the dehulled grain changed slowly up to a microwave dosage of 972 J/g after that it changed vividly darker than the control. The dehulling and dhal yields and colour change were polynomial functions of microwave dosage. The highest yield of 73.7 % was achieved at about 972 J/g with a little change in colour (CIELAB ΔE* value of 2.58). The corresponding dehulling time, cooking time and losses during dehulling were respectively 185 s, 10 min and 15.1 % as compared to 492 s, 20 min and 31.5 % for control respectively. It is concluded that a dosage of about 972 J/g was the best for the black gram dehulling at a rate of 630 W or higher power level.

Effect of soaking and cooking on dietary fibre components of different type of chickpea genotypes

Processing is an important and essential component to enhance the digestibility of essential nutrients of grains. Dietary fibres play an important role in bringing health advantages in chickpea and help in lowering plasma cholesterol. Changes during soaking and soaking followed by cooking on cellulose, hemicellulose, lignin and pectin contents of four genotypes of desi type (KWR 108, JG 74, DCP 92-3 and BG 256), four genotypes of kabuli types (KAK 2, JKG 1, BG 1053, and L 550) and two genotypes of green seed type (BGD 112 and Sadabahar) of chickpeas (Cicer arietinum, L.) was studied. Cellulose, lignin and pectin increased during soaking and cooking, whereas hemicellulose increased during soaking but decreased drastically during cooking. Cellulose recorded an overall increase of 40% during cooking, followed by 15.7% and 15.2% increase in pectin and lignin, respectively during cooking of chickpea grain. Hemicellulose, on the contrary showed a decrease of 26.8% during cooking.

Influence of germination on bioaccessible iron and calcium in pearl millet (Pennisetum typhoideum)

Pearl millet is the staple for economically poorer section of the world's population and improving its mineral bioaccessibility is one of the important approaches to promote its utilization. In the absence of any data on the bioaccessible mineral content from commercially available millet, two varieties namely Kalukombu (native) and Maharastra Rabi Bajra (hybrid) were germinated and its effect on the bioaccessible iron and calcium content was explored using an in-vitro method which simulates gastrointestinal digestion. The millet was germinated for 72 h to facilitate maximum mineral extraction. The bioaccessibility of iron and calcium was considerably enhanced upon sprouting. This higher bioaccessibility could be attributed to decrease in antinutritional factors like phytate and oxalate as a result of germination. Changes in mineral and antinutrient content during sprouting led to significant variations in the antinutrient/mineral molar ratios which had a positive impact on the bioaccessible mineral content. Use of tap water for soaking prior to germination revealed contamination of the millet with iron. Contaminant iron in Kalukombu variety appeared to be less accessible; while the same was potentially bioaccessible in Maharashtra Rabi Bajra variety. Hence bioaccessibility of iron depends on the form in which it is present. The actual bioaccessibility of contaminated iron needs to be further investigated.

Effect of soaking and ultrasound treatments on texture of chickpea

Effect of soaking time (20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480 and 500 min) and temperature (20, 30, 40, 50, 60, 70, 87, 92 and 97°C) together with ultrasound application (25 kHz 100 W and 25 kHz 300 W) on texture of chickpea was investigated. Soaking time, temperature, application of ultrasounds and power of ultrasounds had significant effect (P < 0.05) on texture of chickpea. An Asymptotic first order texture model was successfully fitted to correlate texture of chickpea with soaking time and temperature. Texture model rate constant (kF) increased from 1.68 × 10(-4) to 19.20 × 10(-4) s(-1) for a temperature change from 20 to 97°C without and with 25 kHz 100 W, 25 kHz 300 W ultrasound treatments. Average gelatinization temperature of chickpea using the model was found to be 60 ± 1°C. Activation energy (Ea) values of chickpea for below and above gelatinization temperature were found to be 26.49 and 9.73 kJ mol(-1), respectively. Time to reach equilibrium texture level (te) of soaked chickpeas decreased from 941 to 82 min with increase of temperature from 20 to 97°C ultrasounds of 25 kHz 100 W and 25 kHz 300 W. In the food industry, chickpea is pre-processed (soaked and cooked) to produce humus, canned products and blended powder products. Ultrasonic treatments can be applied to soften and inturn decrease the cooking time of the chickpeas.

Antinutrients and digestibility (in vitro) of soaked, dehulled and germinated cowpeas

Phytic acid, polyphenols, protein and starch digestibility (in vitro) in two varieties, namely CS-46 and CS-88, of soaked, dehulled and germinated cowpeas were determined. Soaking for 12 hours, dehulling of soaked seeds and germination for different time periods (24, 36 and 48 h) contributed significantly in reducing the phytic acid and polyphenol content of cowpeas. Removal of seed coat (dehulling) of soaked cowpeas reduced the polyphenols by 70-71%. Soaking (12 h) brought about an improvement in protein and starch digestibility which further increased after dehulling. Progressive increase in digestibility (protein and starch) was noticed, with an increase in germination period. Dehulling of soaked seeds was most effective in reducing the polyphenolic content, and germination in enhancing protein and starch digestibility.