Reduction efficiency of the neurotoxin β‐ODAP in low‐toxin varieties of Lathyrus sativus seeds by solid state fermentation with Aspergillus oryzae and Rhizopus microsporus var chinensis

Solid state fermentation of several low‐toxin varieties of grass pea (Lathyrus sativus L) seeds with Aspergillus oryzae and Rhizopus microsporus var chinensis removed the neurotoxin β‐ODAP (3‐N‐oxalyl‐L ‐2,3‐diaminopropanoic acid) to a considerable degree from the seed meal. The detoxification efficiency was statistically significant and ranged from 52.4% (p < 0.01) to 82.2% (p < 0.001), which was lower than for a high‐toxin variety processed by the same fermentation procedure (94.8%, p < 0.001). While the content of β‐ODAP decreased, those of other free protein amino acids, especially glutamic acid, histidine, threonine, tyrosine, valine and lysine, increased dramatically in the fermented seeds. Efforts to remove the neurotoxin from Lathyrus sativus either by breeding or by food processing to obtain toxin‐free grass pea seeds have been made worldwide for several decades. The efficiencies of various reported processing methods are summarised and compared. © 2000 Society of Chemical Industry     

Composition and in vitro digestibility of raw versus cooked white‐ and colour‐flowered peas

Ten pea cultivars (four white‐flowered, Pisum sativum ssp. hortense, and six colour‐flowered, Pisum sativum ssp. arvense) grown in Latvia were analyzed and tested in in vitro experiments, as raw and cooked seeds. The colour‐flowered (CF) had a greater proportion of hulls and a higher acid detergent fibre (ADF) content than white‐flowered (WF) pea seeds (10.7 vs. 8.2% and 92.2 vs. 84.5 g/kg dry matter (DM), respectively). Three out of six CF varieties had a significantly greater amount of protein bound to neutral detergent fibre (NDF) than WF peas. The tannin content was higher in CF than in WF peas (8.46 vs. 0.37 g/kg DM). In vitro protein and amino acid digestibility was about 8% higher in WF than in CF varieties. Cooking decreased the tannin content in CF peas (8.46 vs. 5.51 g/kg DM) but had no effect on in vitro protein digestibility. Heat treatment reduced significantly trypsin inhibitor activity and amount of protein bound to NDF in CF and WF varieties (from 6.50 to 0.52 and from 6.54 to 0.46 trypsin inhibitor units (TIU)/mg DM; from 1.250 to 0.831 and 0.761 to 0.209 g N/100 g NDF, respectively). However, the protein bound to NDF content in pea DM increased in CF and decreased in WF varieties (from 1.525 to 2.145 and from 0.913 to 0.502 g N/kg DM, respectively). Cooking resulted in an increased NDF content over two times in both CF and WF pea seeds (from 122 to 259 and from 120 to 262 g/kg DM, respectively). The results suggest that colour‐flowered pea may be considered as an interesting dietary alternative to white‐flowered pea since cooking removes trypsin inhibitor activity (TIA), decreases tannins, and increases dietary fibre contents.     

Nutritional value of African yambean (Sphenostylis stenocarpa,L): improvement by solid substrate fermentation using the tempeh fungus Rhizopus oligosporus

The tropical African yambean (AYB, Sphenostylis stenocarpa L.) is a hardy, protein‐rich under‐utilised African legume. Anti‐nutrients, and the excessively long cooking time (4–6 h), among other factors, limit the food use of African yambean seeds. To reduce these limitations, non‐traditional, less energy consuming processing methods are required. Seeds of different varieties were (1) examined for proximate composition and (2) fermented with Rhizopus oligosporus for the production of tempeh. The traditional production process involves dehulling, soaking in water for 24 h, boiling in water for 30 min, inoculation and fermentation. In addition, the traditional procedure for preparing tempeh was modified by using 1% citric acid solution instead of water for soaking and cooking. Comparisons with traditionally cooked beans, which involved boiling in water for 4 h, were made. The traditional tempeh procedure resulted in a slight but significant increase in protein and starch (P < 0.05) and an almost complete loss of most of the anti‐nutrients of AYB seeds, although the cyanogenic glycoside content of AYB‐white remained high. The modified procedure resulted in a bacteria‐free tempeh and the cyanogenic glycosides were no longer detectable. In vitro protein digestibility of the 1% citric acid treated sample was slightly lower than that of the water‐treated sample. Both tempeh production processes were clearly more effective and less energy intensive than traditional cooking in improving nutritional quality, but only the modified method of tempeh production eliminated the possibility of cyanide poisoning. Copyright © 2006 Society of Chemical Industry     

Relationship between proportion and composition of albumins,and in vitro protein digestibility of raw and cooked pea seeds (Pisum sativum L.)

BACKGROUND: Peas provide an excellent plant protein resource for human diets, but their proteins are less readily digestible than animal proteins. To identify the relationship between composition and in vitro digestibility of pea protein, eight pea varieties with a wide range of protein content (157.3–272.7 g kg^?1) were determined for the proportion of albumins and globulins, their compositions using sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and in vitro protein digestibility (IVPD) before and after heat treatment using a multi‐enzyme (trypsin, chymotrypsin and peptidase) method. RESULTS: The proportion of albumins based on total seed protein content decreased from 229 to 147 g kg^?1 as seed protein content increased from 157.3 to 272.7 g kg^?1, while the proportion of globulins increased from 483 to 590 g kg^?1. The IVPDs of eight raw pea seeds were 79.9–83.5%, with significant varietal variations, and those were improved to 85.9–86.8% by cooking. Albumins, including (pea albumins 2) PA2, trypsin inhibitor, lectin and lipoxygenase, were identified as proteolytic resistant proteins. Globulins were mostly digested by protease treatment after heating. CONCLUSION: The quantitative ratio of albumins and globulins, and the quantitative variations of albumin protein components, including lipoxygenase, PA2, lectins and trypsin inhibitors, appear to influence the protein digestibility of both raw and cooked pea seeds. Copyright © 2010 Society of Chemical Industry     

Nutritional quality of legume seeds as affected by some physical treatments 2. Antinutritional factors

Raw and treated cowpea, pea and kidney bean seeds were investigated for their content of antinutritional factors including tannins, phytic acid, trypsin inhibitors and oligosaccharides. Treatments applied included water soaking, boiling, roasting, microwave cooking, autoclaving, fermentation and micronization. Kidney bean contained the highest antinutrient content among all investigated seeds. The least tannins and phytic acid contents were recorded in Canadian cowpea while Canadian pea showed the lowest TIA. All treatments conducted caused significant decreases in tannins, phytic acid, TIA and oligosaccharides as compared to the raw seeds. Boiling caused the highest reduction in tannins followed by autoclaving and microwave cooking. Autoclaving and fermentation were the most effective in reducing phytic acid content. Heat treatments (boiling, roasting, microwave cooking and autoclaving) brought a total removal of trypsin inhibitors of all samples. Furthermore, autoclaving caused the highest reduction in oligosaccharides followed by fermentation while the least reductions were caused by either roasting or micronization with no significant difference between these two treatments.     

Nutritional value of African yambean (Sphenostylis stenocarpa L): improvement by lactic acid fermentation

Tropical African yambean (Sphenostylis stenocarpa L) is an under‐utilised hardy, protein‐rich legume. Antinutrients and the excessively long cooking time (4–6 h), among other factors, limit the food use of African yambean seeds. To reduce these limitations, non‐traditional, less energy‐consuming processing methods are required. Seeds of different varieties were (i) examined for ingredients and (ii) fermented with Lactobacillus plantarum. Comparisons with traditionally cooked beans were made. Protein content and in vitro protein digestibility were increased slightly by fermentation or cooking. Reductions in trypsin and α‐amylase inhibitor activity and tannin ranged from significant to complete. The contents of potentially very toxic cyanogenic glycosides and flatulence‐causing α‐galactosides were high in raw beans. Reduction by fermentation (by 85%) was clearly more effective than by traditional cooking (10–20%). The results demonstrate (i) that fermentation can substantially improve the nutritional quality and (ii) that the energy requirement to produce a basic consumable fermented food from African yambean is only 10% of that of traditional cooking. On these grounds, widespread application of lactic acid fermentation by individuals or small‐scale industries would be advantageous in the context of small‐household economy, environmental protection, health and long‐term sustainable agriculture in Nigeria. Copyright © 2005 Society of Chemical Industry     

Contribution of low‐molecular‐weight antioxidants to the antioxidant capacity of raw and processed lentil seeds

In this study four cultivars of lentil originating from Spain were examined: cv Paula, cv Agueda, cv Almar and cv Alcor. Since consumption of these seeds after heat treatment and as sprouts has been popularised, the impact of cooking (up to 30 min) and germination process (in dark, at 25°C, for up to 4 days) on peroxyl radical‐trapping capacity (PRTC) and Trolox‐equivalent antioxidant capacity (TEAC) of the processed seeds was addressed. Also, changes in the content of low‐molecular‐weight antioxidants (LMWA) and soluble proteins in the course of cooking and germination were studied. The analyzed LMWA were: total phenolics, tocopherols (α‐T, β‐T, γ‐T, δ‐T( reduced glutathione, and L ‐ascorbic acid. On the basis of the results obtained, the contribution of LMWA and soluble proteins to the PRTC and TEAC of raw, cooked, and germinated lentil seeds was calculated by multiple mean values for the content of investigated compounds and their relative potential with respect to Trolox. The results showed a very high molar percentage contribution of phenolic compounds and low contribution of tocopherols, glutathione, soluble proteins, and ascorbate (only in germinated seeds) to the total TEAC and total PRTC calculated as a sum of data provided for phosphate‐buffered and 80% methanolic extracts of raw and processed lentil seeds.     

Isolation of obligate anaerobic rumen bacteria capable of degrading the neurotoxin β‐ODAP (β‐N‐oxalyl‐L‐α,β‐diaminopropionic acid) as evaluated by a liquid chromatography/biosensor analysis system

Six pure strains of obligate anaerobes capable of degrading the toxin β‐N‐oxalyl‐L ‐α, β‐diaminopropionic acid (β‐ODAP) contained in grass pea (Lathyrus sativus) have been isolated from cow rumen. The new isolates were identified as Megasphaera elsdenii (five different genotypes) and Clostridium bifermentans using 16S rDNA analysis. The β‐ODAP degrading efficiency of the isolates was evaluated by measuring the amount of β‐ODAP in the growth medium, which contained β‐ODAP as the only carbon source, before and after incubation with the microbes. The method of analysis was liquid chromatography employing bioelectrochemical detection. The biosensor is based on co‐immobilising two enzymes, glutamate oxidase (GlOx) and horseradish peroxidase (HRP), on the end of a spectrographic graphite electrode. β‐ODAP is oxidised by GlOx to form H₂O₂, which in turn is bioelectrocatalytically reduced by HRP through a mediated reaction using a polymeric mediator incorporating Os^{2 + /3+} functionalities rapidly shuttling electrons with the electrode_giving rise to the analytical signal. On the basis of this analysis system, the new isolates are capable of utilising β‐ODAP as sole carbon source to a maximum of 90–95% within 5 days with concomitant increase in cell protein. Copyright © 2005 Society of Chemical Industry     

Effects of Processing on the Reduction of β-ODAP (β-N-Oxalyl-L-2,3-diaminopropionic acid) and Anti-Nutrients of Khesari Dhal,Lathyrus sativus

Effects of different processing techniques on the neurotoxin, β-ODAP (β- N -oxalyl-L-2,3-diaminopropionic acid), and the anti-nutritional compounds (phytate, polyphenols, trypsin and amylase inhibitors, and lectins) within four lines of Lathyrus sativus (high-, medium- and low-ODAP, and so-called ODAP-free) were investigated. Soaking of seeds in various media reduced the contents of these compounds to a varying and significant extent; losses were higher in freshly boiled water, alkaline and tamarind solutions than after soaking in drinking water. The highest losses in boiled water (65–70%) were observed for β-ODAP, followed by trypsin inhibitors (42–48%) and polyphenols (30–37%). Ordinary cooking and pressure cooking of pre-soaked seeds were found to be most effective in reducing the levels of all the natural toxicants examined, whilst fermentation and germination were more effective in destroying both of the enzyme inhibitors (amylase inhibitors by 69–71%; trypsin inhibitors by 65–66%) than either phytates or polyphenols. Lectins were not affected by most of these processes except by pressure cooking and fermentation. Dehusking of pre-soaked seeds significantly reduced β-ODAP levels, but this reduction was lower for the anti-nutrients. These findings and the high water solubility suggest that a simple and effective means of detoxifying Lathyrus by removing this neurotoxic amino acid may be practicable.     

Comparative effect of boiling and solid substrate fermentation using the tempeh fungus (Rhizopus oligosporus) on the flatulence potential of African yambean (Sphenostylis stenocarpa L.) seeds

The tropical African yambean (AYB, Sphenostylis stenocarpa L.) is a protein-rich underutilized African legume. The presence of the flatulence- and diarrhoea-causing raffinose family oligosaccharides (RFO: raffinose, stachyose and verbascose) or α-galactosides has limited the food use of African yambean seeds. To reduce this limitation, non-traditional processing methods are required. Seeds of three varieties were (i) examined for the flatulence- and diarrhoea-causing RFO and (ii) fermented with Rhizopus oligosporus for tempeh production. The traditional tempeh production process involved dehulling, soaking in water for 24 h, boiling in water for 30 min, inoculation and fermentation. In addition, the traditional tempeh procedure was modified by using 1% citric acid solution instead of water for soaking and cooking. Comparisons with traditionally cooked beans, which involved boiling in water for 4 h, were made. Boiling seeds for 4 h resulted in 8–30% reduction of total α-galactosides in the three varieties, while the traditional tempeh procedure resulted in an almost complete loss (98%) of the same (P < 0.05). The modified procedure resulted in a bacteria-free tempeh but α-galactoside reduction was 22–39%. Both tempeh production processes were clearly more effective than was traditional cooking in reducing the flatulence potential of the AYB seeds.     

Growth potential of Salmonella infantis and Escherichia coli in fermenting tempeh made from horsebean,pea and chickpea and their inhibition by Lactobacillus plantarum

Salmonella infantis and Escherichia coli multiplied to varying degrees during the fermentation of unacidified horsebean, pea and chickpea tempeh. Active mycelial growth on the beans resulted in a sharp increase in pH. This was always accompanied by a sharp increase in the growth rate of the test organisms. Acidification of the beans during soaking decreased the growth rate of the test organisms only until active mycelial growth started. Inoculation of cooked beans with Lactobacillus plantarum resulted in a complete inhibition of E coli in unacidified and acidified chickpea tempeh and acidified pea tempeh. Marked inhibition of E coli was also noted in unacidified pea tempeh and acidified horsebean tempeh. S infantis was also completely inhibited by L plantarum in unacidified and acidified chickpea tempeh. In pea and horsebean tempeh, counts of S infantis were always lower in Lactobacillus-inoculated fermenting beans than in the control. Beside the pH, undissociated acids and other substances produced by L plantarum may be inhibitory to the test organisms. The use of L plantarum may be considered for the control of pathogens during commercial-scale tempeh production.     

In vitro digestibility of processed and fermented soya bean,cowpea and maize

Tropical legumes, ie soya bean and cowpea, were pre‐treated and subsequently fermented using pure cultures of Rhizopus spp. Impact of soaking, cooking and fermentation of the legumes on their digestibility was determined using an in vitro digestion method. Processing of white maize included, amongst others, natural lactic acid fermentation, cooking and saccharification using barley malt. An in vitro method was standardised to carry out comparative determinations of the dry matter digestibility of cereal and legume food samples as a function of processing conditions, without attempting to exactly mimic gastrointestinal digestion. Using this method based on upper digestive tract digestion, it was observed that digestibility of the legumes increased during cooking and fermentation. Cooking improved the total digestibility of both soya bean and cowpea from 36.5 to 44.8% and from 15.4 to 40.9% respectively. Subsequent fungal fermentation increased total digestibility only by about 3% for both soya bean and cowpea. Digestibility was also influenced by fungal strain and fermentation time. Cooking and subsequent saccharification using malt almost tripled total digestibility of white maize from 25.5 to 63.6%, whereas lactic fermentation of maize had no effect on in vitro dry matter digestibility. Although total digestibility of cooked legumes was only slightly improved by mould fermentation (3% for both soya bean and cowpea), the level of water‐soluble dry matter of food samples increased during fermentation with Rhizopus oryzae from 7.0 up to 27.3% for soya bean and from 4.3 up to 24.1% for cowpea. These fermented products could therefore play a role as sources of easily available nutrients for individuals suffering from digestive disorders. © 2000 Society of Chemical Industry     

Extractability of antioxidants from legume seed flour after cooking and in vitro gastrointestinal digestion in comparison with methanolic extraction of the unprocessed flour

Antioxidant activities were studied in methanolic and water extracts of nonprocessed, cooked and in vitro enzymatically digested seed flour, as well as in total protein hydrolysates and small peptide fractions (<3 and <10 kDa) of three pea and five grass pea cultivars. The antioxidative properties were determined by three spectrophotometric methods: 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assay, Folin‐Ciocalteu (FC) reducing capacity assay and H₂O₂ scavenging. We also applied one luminometric assay for hydroxyl radical scavenging. The study showed that cooking and enzymatic digestion strongly enhanced the release of phenolic compounds in methanolic extracts of four analysed cultivars. Scavenging activity against DPPH radical, hydroxyl radical and hydrogen peroxide was increased in majority of analysed flour specimens subjected to processing. Our findings indicate that, besides the phenolic compounds, the small peptide fraction, especially the MW <3 kDa, in methanolic and aqueous extracts of cooked and digested seed flour significantly contribute to free radical and hydrogen peroxide scavenging activity in all investigated cultivars. Our data strongly suggest that simple cooking treatment and in vitro digestion of seed flour applied prior to extraction with methanol could improve antioxidative activity of obtained extracts.     

Non-volatile components of several novel species of edible fungi in China

A nonprotein neurotoxic amino acid, β-N-oxalyl-l-2,3-diaminopropionic acid (ODAP), found in Lathyrus sativus (grass pea or chickling vetch) seeds is known to be relatively heat stable. The present study aims at development of a kinetic model for degradation of ODAP in Lathyrus sativus subjected to a defined set of processing conditions. This study was carried out at pH 4.0 and 9.2. Isothermal condition experiments were carried out over a temperature range of 60–120 °C. For nonisothermal conditions, three different cooking methods viz., – open pan, pressure cooking and cooking in recently developed and patented fuel efficient ‘EcoCooker’ were used. The degradation of ODAP was adequately modeled by Arrhenius type of equation. A mathematical model based on the time temperature data of the nonisothermal heat process and isothermal kinetic rate parameters has been developed to predict the degradation of ODAP in any nonisothermal heating process of known time temperature profiles.     

Effects of Experimental Cooking on the Yield and Proximate Composition of Three Selected Legumes

Dry mature seeds of field pea (Pisum arvense), moth bean (Vigna aconitifolia) and pigeon pea (Cajanus cajan) were investigated for their chemical and cooking characteristics. The crude protein (N × 6.25) content was 24.5% for field pea (8.5% moisture basis), 22.7% for moth beans (10% moisture basis) and 21.3% for pigeon pea (10% moisture basis). Ratios of cooked weight/dry weight after cooking the whole and dehulled seeds were 2.14 and 2.18, 2.20 and 2.30, and 2.43 and 2.51 for the field pea, moth bean and pigeon pea, respectively. Dehulling increased the protein, fat and energy contents but decreased the ash and fiber contents as well as cooking times. On cooking, the true retentions of proximate principles were good.     

Effect of cooking on protein quality of chickpea (Cicer arietinum) seeds

Amino acid composition and in vitro protein digestibility of cooked chickpea were determined and compared to raw chickpea seeds. Heat treatment produced a decrease of methionine, cysteine, lysine, arginine, tyrosine and leucine, the highest reductions being in cysteine (15%) and lysine (13.2%). Protein content declined by 3.4% and in vitro protein digestibility improved significantly from 71.8 to 83.5% after cooking. The decrease of lysine was higher in the cooked chickpea seeds than in the heated protein fractions, globulins and albumins. The structural modification in globulins during heat treatment seems to be the reason for the increase in protein digestibility, although the activity of proteolytic inhibitors in the albumin fraction was not reduced. Results suggest that appropriate heat treatment may improve the bioavailability of chickpea proteins.     

Lactic acid fermentation of black beans (Phaseolus vulgaris): microbiological and chemical characterization

Legumes, and particularly Phaseolus vulgaris, are an important source of nutrients, especially in developing countries. In spite of being part of the staple diets of these populations, their consumption is limited by the flatulence they produce. Natural lactic acid fermentation has proved to be an effective method to decrease flatulence‐producing compounds. However, in order to use this method as a process on a large scale, it is fundamental to identify the microbial flora involved. When fermented seeds of Phaseolus vulgaris (black bean) were analysed microbiologically, it was found that the microorganisms present were Lactobacillus casei and Lactobacillus plantarum. On performing back‐slopping or induced fermentation with different inocula, a 63.35% decrease was found for the soluble fibre and 88.6% for raffinose, one of the main flatulence‐producing compounds. When cooking under atmospheric pressure was applied to the fermented samples, a significant diminution of the trypsin inhibitors and tannins was found as well as an increase in the in vitro and in vivo digestibility of the beans. All these results demonstrate that the lactic acid bacteria used for the induced fermentation can lead to a functional food with improved nutritional quality. Copyright © 2006 Society of Chemical Industry     

Microbial development during tempeh fermentation from various beans and effect of Lactobacillus plantarum on the natural microflora

The microbial development during the fermentation of tempeh made of unacidified and acidified horsebean, pea, chickpea and soybean was studied. Increase in microbial count was observed during the fermentation of the various beans. Bacillus spp. and coryneform bacteria dominated the microflora of unacidified, and streptococci of acidified horsebean tempeh. In pea tempeh, lactobacilli dominated, in chickpea, micrococci, staphylococci and coryneform bacteria and in soybean tempeh, enterococci were the dominant genera. Inoculation of the cooked beans with Lactobacillus plantarum resulted in a lower pH and lower total counts in the various products. The use of Lb. plantarum in tempeh production may control the proliferation of undesirable microorganisms.     

Non-Starch Polysaccharides and in Vitro Starch Digestibility of Raw and Cooked Chick Peas

The effects of domestic and industrial cooking methods on the non-starch polysaccharides (NSP) content and in vitro starch digestibility of chick pea (variety “blanco lechoso”) have been studied. Total and soluble NSP increased, as did the slowly digestible starch (SDS), whereas the resistant starch (RS) fraction decreased after cooking, showing higher content in domestic than industrially cooked chick peas. The in vitro starch digestible rate index (SDRI) was similar in the cooked chick peas, as was the rapidly available glucose (RAG). Due to the low values of RAG, chick peas would give a slow post-prandial glycaemic response. Domestic cooked chick peas consumption would increase the intakes of RS in human diet, whereas the industrially cooked chick peas with lower content of RS would result in less flatulence problems.     

Processing peas for producing macaroni

 Pea flour from green and yellow mature pea seeds (Pisum sativum) was processed by adding emulsifiers (Glycerol-monostearate GMS, and Amidan 250B polar type monoglyceride, A250). Doughs obtained were cooked for 15 min and 30 min in order to investigate the effect of the presence of emulsifiers and cooking treatment. The quality of macaroni was examined, cooking properties were defined and sensory assessment established. Changes in protein structure were studied by solution fractioning and SDS-PAGE. Modification of the monosaccharide, disaccharide and α-galactoside contents and trypsin inhibitor activity (TIA) were also studied. The addition of emulsifiers improved dough quality. Emulsifiers fundamentally change the solubility of protein fractions, and they were able to promote the soluble fraction molecular weight distribution and the infiltration of low molecular weight fractions into the protein network. The soluble carbohydrate content was not modified by the addition of emulsifiers whilst cooking time affected its content. α-Galactoside content and TIA were reduced after the addition of emulsifiers and the cooking of peas. Received: 2 November 1995/Revised version: 12 February 1996