Faba Protein Research Articles

3D printing of prawn mimics with faba proteins: The effects of transglutaminase and curdlan gum on texture

With its capability for automated production of high-resolution structures, 3D printing can develop plant-based seafood mimics with comparable protein content. However, the challenge lies in solidifying 3D printed products to achieve the firmness of seafood. Targeting prawn, texturisation of its 3D printed mimic by curdlan gum was compared against incubation with a protein cross-linking enzyme, microbial transglutaminase. Faba bean protein extract (FBP) was selected for its lightest colour. To confer structural stability to the FBP-based ink without hindering extrudability, adding 1 % xanthan gum was optimal. Printed curdlan-containing mimics were steamed for 9 min, while printed transglutaminase-containing mimics were incubated at 55 °C before steaming. Either adding 0.0625 % or 0.125 % w/w curdlan or, incubating the transglutaminase-containing mimics for an hour achieved chewiness of 818.8–940.6 g, comparable to that of steamed prawn (953.13 g). Curdlan hydrogel penetrated and reinforced the FBP network as observed under confocal imaging. Whereas incubation of transglutaminase-containing mimics enhanced microstructural connectivity, attributable to transglutaminase-catalysed isopeptide cross-linkages, and the consequent increase in disulfide bonding and β-sheet. Ultimately, transglutaminase treatment appeared more suitable than curdlan, as it yielded mimics with cutting strength comparable to steamed prawn. Both demonstrated promising potential to broaden the variety of 3D printed seafood mimics.

Development of a Clean Label Mayonnaise Using Fruit Flour.

Over the past few years, clean label food has been growing, meaning that consumers are searching for shorter and simpler ingredient lists composed of familiar and natural ingredients. The objective of the present work was to develop a vegan clean label mayonnaise, replacing the additives with fruit flour obtained from fruit reduced commercial value. The mayonnaises were prepared by replacing the egg yolk with 1.5% (w/w) lupin and faba proteins, while fruit flour (apple, nectarine, pear, and peach flour) was incorporated to substitute sugar, preservatives, and colorants. Texture profile analysis and rheology-small amplitude oscillatory measurements were performed to evaluate the impact of the fruit flour on mechanical properties. The mayonnaise antioxidant activity was also analyzed in terms of color, pH, microbiology, and stability measurements. The results showed that mayonnaises produced with fruit flour had better structure parameters in terms of viscosity, and texture, but also improved pH and antioxidant activity (p < 0.05) compared to the standard mayonnaise (mayonnaise without fruit flour). The incorporation of this ingredient into mayonnaise increases the antioxidant potential, though it is in lower concentrations compared to the fruit flours that compose them. Nectarine mayonnaise showed the most promising results in terms of texture and antioxidant capacity (11.30 mg equivalent of gallic acid/100 g).

In Vitro Digestion and Colonic Fermentation of UHT Treated Faba Protein Emulsions: Effects of Enzymatic Hydrolysis and Thermal Processing on Proteins and Phenolics.

Faba bean (Vicia faba L.) protein is a new plant protein alternative source with high nutrient content especially protein and phenolic compounds. The present study investigated physicochemical properties, phenolic content, antioxidant potential, and short chain fatty acids (SCFAs) production during in vitro digestion and colonic fermentation of faba bean hydrolysates and oil-in-water (O/W) emulsions. Results indicate that the enzymic hydrolysates of faba proteins exhibited higher protein solubility, increased electronegativity, and decreased surface hydrophobicity than native faba protein. O/W emulsions showed improved colloidal stability for the faba protein hydrolysates after ultra-high temperature processing (UHT). Furthermore, UHT processing preserved total phenolic content, DPPH and ABTS radical scavenging abilities while decreasing total flavonoid content and ferric reducing power. Besides, the release of phenolic compounds in faba bean hydrolysates (FBH) and emulsions (FBE) improved after intestinal digestion by 0.44 mg GAE/g and 0.55 mg GAE/g, respectively. For colonic fermentation, FBH demonstrated an approximately 10 mg TE/g higher ABTS value than FBE (106.45 mg TE/g). Total SCFAs production of both FBH and FBE was only 0.03 mM. The treatment of FBH with 30 min enzymatic hydrolysis displayed relatively higher antioxidant capacities and SCFAs production, indicating its potential to bring more benefits to gut health. Overall, this study showed that enzymic hydrolysis of faba proteins not only improved the colloidal emulsion stability, but also released antioxidant capacity during in vitro digestibility and colonic fermentation. Colonic fermentation metabolites (SCFAs) were related to the degree of hydrolysis for both FBH and FBE. Additional studies are required to further elucidate and differentiate the role of phenolics during faba protein processing and digestion stages in comparison to contributions of peptides, amino acids and microelements to digestion rates, antioxidant capacities and colonial SCFA production.

How can processing technologies boost the application of faba bean (Vicia faba L.) proteins in food production?

AbstractFaba bean (Vicia faba L.) has attracted increasing interest as a high source of proteins for human nutrition. However, the application of faba bean proteins is still limited due to their low functional properties. Several processing technologies were used to enhance these features starting with the selection of the appropriate pretreatments to favorize protein extractability and to ensure their safety by removing/degrading the antinutritional factors; extraction methods (dry fractionation or wet extraction) and posttreatments to produce multifunctional protein ingredients. In this frame, this review aims to provide a better understanding of the production chain of faba proteins and discuss the impact of processing on protein characteristics based on a recent critical compilation of scientific literature. The different processing applied to faba proteins impacted different degrees of nutritional, functional, sensory, and biological properties. Depending on the final food product, a combination of technologies can be designed to meet specific properties. It must be kept in mind that besides quality, price, sustainability, and scaling up feasibility are relevant factors to consider in the selection of processing.

Modulating the fat globules of plant-based cream emulsion: Influence of the source of plant proteins

In this study the physical properties of plant-based cream emulsion using various plant-proteins and homogenisation pressures were investigated. Three plant proteins (soy protein isolate-SPI, faba protein isolate-FBI, and pea protein isolate-PPI) at 2, 3 and 4% (w/w) concentrations were emulsified with 36% plant-fat (a mixture of palm oil, sunflower oil and monodiglyceride) and passed through two-stage homogenisation pressures at 25/5, 10/4, and 7/3 MPa. Increasing homogenisation pressure and protein content reduced the fat globule size as observed in microstructure images but increased the particles size (D[4,3]) in emulsion. All emulsions had high zeta potential values (−25 to −49 mV) suggesting stable emulsions with a firm and thick consistency. The friction coefficient of creams with PPI was significantly lower than SPI and FBI, indicating better lubrication properties. The results obtained suggests the ability to produce stable plant-based cream from plant-based proteins and fat that can replace the dairy cream.

Faba bean protein in reduced fat/cholesterol mayonnaise: extraction and physico-chemical modification process.

Effect of faba bean enzymatic protein extraction process parameters were investigated at different ultrasound powers (200, 300 and 400W), sonication times (15, 25 and 35min), enzyme dosages (0.15, 0.3 and 0.45%) and enzyme treatment times (15, 25 and 35min). Physico-functional characterization of the protein samples through solubility, zeta potential, color, fat adsorption, emulsifying and foaming capacity measurements suggested faba protein as a promising substituent to egg yolk powder in reduced fat mayonnaise formulation. Reduced-fat mayonnaise formulation containing different faba protein/egg yolk powder ratios were prepared and characterized through rheological analyses as well as emulsion stability, texture, color and microstructural evaluations. The formulations containing equal compositions of faba bean protein and egg yolk powder (0.375%) and also the one with 0.5% faba bean protein and 0.25% egg yolk powder were finally suggested to substitute the conventional formulation.

Effect of dry fractionated hybrid protein ingredients on the structural, textural, thermal and sensory properties of gluten‐free oat and faba pasta

SummaryProtein‐enriched gluten‐free pasta was prepared from oat starch‐rich endosperm (SRE), which was substituted with different proportions of oat protein concentrate (OPC) and/or faba protein concentrate (FPC) fractions in order to obtain a similar protein content (18% and 35%). Accordingly, the health claims ‘source of protein’ and ‘high protein’ were achieved. Pasta with OPC and FPC had lower optimal cooking time (8 and 6.3 min), cooking loss (6% and 10.2% dm) and water absorption (152% and 147%) than control SRE pasta (9.3 min; 12.3% dm and 185%). Addition of protein concentrates produced an increase in hardness and chewiness of spaghetti. The glycaemic index of pasta was lowered by the addition of protein ingredients, the lowest value being achieved with FPC. In vitro protein digestibility of pasta increased up to 3.5% for OPC and up to 7.1% in case of FPC addition. The most protein‐digestible pasta was that with FPC addition to reach 35% protein content.

Assessment of the microstructural characteristics and the in vitro bioactive properties of sunflower oil-based emulsions stabilized by fava bean (vicia faba) protein

Much interest is currently focused on plants such as legumes as an alternative source of protein for human nutrition. In this work a Vicia faba (fava bean, FB) protein concentrate was characterised for its ability to stabilise sunflower oil, oil-in-water (o/w) emulsions at three different pHs (3.0, 5.0 and 8.0). Emulsion microstructure was characterised by droplet size distribution (DSD) and optical microscopy, and resulting rheological properties were assessed. Smaller droplet sizes and better rheological properties (G′ and G″) were obtained at pH 3.0 and 8.0, i.e., at pH values away from the isoelectric point (pH 5.0). The in vitro bioactive properties of the emulsions at pH 3.0, 5.0 and 8.0 were tested using the ferric-reducing antioxidant power (FRAP) and the oxygen radical absorbance capacity (ORAC) antioxidant assays. The angiotensin converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory activities were also determined. The highest antioxidant activity was observed when the emulsions were generated at pH 8.0 with FRAP and ORAC values of 935.7 ± 151.5 and 368.8 ± 2.3 μmol Trolox Eq. · g−1 of emulsion, respectively. Overall, the emulsions were poor inhibitors of ACE and DPP-IV. However, subjection of the emulsions to in vitro simulated gastro-intestinal digestion (SGID) released peptides which increased ACE and DPP-IV inhibitory activity (67.4 ± 2.7% and 11.2 ± 1.1%, respectively, for emulsions generated at pH 8). The emulsions generated at pH 3.0 displayed the lowest extent of lipid oxidation following 15 d storage. These results show the capability of FB protein concentrate to stabilise o/w emulsions while also demonstrating antioxidant along with ACE and DPP-IV inhibitory properties following gastrointestinal digestion.

FUNCTIONAL PROPERTIES OF FABA BEAN PROTEIN AND EFFECT OF ENZYMATIC HYDROLYSIS ON ITS ANTIOXIDANT ACTIVITY

Protein play an important role in determining structure and texture of various foodproducts. Therefore, the goals of this research were to study the functional properties of faba beanprotein cultivar, Giza3, compared to s-Lactoglobulin (s-Lg) and to hydrolyze this protein using pepsinat different pH values (1.5 and 3) and different incubation periods (0, 5, 10, 60, and 180 min) tocharacterize the resultant hydrolysates and evaluate their antioxidant activities. The solubility atdifferent pH, emulsifying properties, stability against creaming and oil droplets size, of faba beanprotein were tested compared to s-Lg protein. The findings cleared that the solubility and emulsifyingproperties of faba protein were very low compared to s-Lg. Concerning to hydrolysis process, thedegree of hydrolysis at pH 1.5 was higher than that at pH 3. The molecular weight distribution bandsof faba protein hydrolysates were in the range of 9–98 kDa using SDS-PAGE method while, peptideswere in the range of 500 – 4000 Da using MALDI-TOF MS method. The results of both methodsconfirmed that the hydrolysis at pH 1.5 was higher than pH 3. Moreover, the enzymatic hydrolysissignificantly improved the antioxidant activity of faba bean protein. Hydrolysates produced at pH 3had a slight high antioxidant activity than at pH 1.5 at all incubation periods. Finally, these resultssuggest that faba bean hydrolysates could be used in preparing functional foods and as naturalantioxidants to prevent oxidation process in food products.

Antioxidant, antityrosinase and antibiofilm activities of synthesized peptides derived from Vicia faba protein hydrolysate: A powerful agents in cosmetic application

The aim of this study was to identify peptides with antioxidant, antityrosinase and antibiofilm activities released from Vicia faba seed proteins hydrolysate. The hydrolysis pattern was performed with trypsin. Firstly, the obtained hydrolysate was fractionated by cation exchange chromatography and the fraction exhibiting the highest biological activity was then analyzed by reverse phase HPLC tandem mass spectrometry. After annotation by Peaks software (BSI, Canada) for de novo peptide sequencing, seven peptides were identified, mainly derived from storage proteins: legumin and vicilin. These peptides were further chemically synthesized to assess their antioxidant capacity, antityrosinase activity and antibiofilm ability against Pseudomonas aeruginosa PA14. Results showed that peptides P5, P6 and P7 identified as LSPGDVLVIPAGYPVAIK, VESEAGLTETWNPNHPELR and EEYDEEKEQGEEEIR respectively, displayed the highest DPPH radical scavenging activity (IC50=0.25–1.9mM). P5 was the only peptide able to chelate iron and reduce Fe3+ to Fe2+. Furthermore, peptides P4 (GPLVHPQSQSQSN) and P6 were observed as potent tyrosinase inhibitors with IC50 values of 1 and 0.14mM respectively. P1, P5, P6 and P7 also showed interesting antibiofilm activity against Pseudomonas aeruginosa PA14 with MBIC50 value ranged from 12 to 35μM. Our data suggest that V. faba seed proteins hydrolysate could be potentially used as a source of natural bioactive peptides for cosmetic and pharmaceutical applications.

Hypocholesterolemic and Anticarcinogenic Effect of Vicia faba Protein Hydrolyzates

ABSTRACTIn recent years, the consumption of vegetal-source proteins has been studied to determine their preventing effect on the development of several chronic diseases. The initial purpose of this report was to determine the effect of a hypercholesterolemic diet (HCD) given to mice, alone or with azoxymethane (AOM), on various obesity biochemical biomarkers, as well as on the induction of colon aberrant crypts (aberrant crypt foci; ACF). At the end of the 5-week assay, animals fed the HCD showed alterations in the level of total cholesterol, high- and low-density lipoproteins, and in the Atherogenic Index; besides, a significant elevation was observed in the number of ACF. Our second aim was to examine the effect of a Faba Protein Hydrolyzate (FPH) on mice fed the HCD. We first obtained protein hydrolyzates from the seeds of Vicia faba, determined the in vitro antioxidant potential with two tests, and, subsequently, evaluated the effect on obesity biomarkers and on the number of ACF. In the first case, we found that, generally, the best protective effect was obtained with the low dose of FPH (10 mg/kg) administered to animals fed the HCD, and injected AOM. With respect to the number of ACF, we observed that this dose was more effective, inhibiting such lesions to almost the level determined for the normocholesterolemic diet (NCD). Therefore, our results demonstrated the relevance of a HCD to develop anomalies in obesity biomarkers in mouse, as well as to increase the number of precarcinogenic lesions. Our results also showed a protective response with the administration of FPH, particularly with a specific dose, suggesting the need for extending research on the matter by widening the spectra of doses, in order to clearly define its potential to counteract the damage induced by the HCD, as well as to confirm if antioxidation in mice was involved in such an effect.

A Substrate Mimic Allows High-Throughput Assay of the FabA Protein and Consequently the Identification of a Novel Inhibitor of Pseudomonas aeruginosa FabA

Eukaryotes and prokaryotes possess fatty acid synthase (FAS) biosynthetic pathways that comprise iterative chain elongation, reduction, and dehydration reactions. The bacterial FASII pathway differs significantly from human FAS pathways and is a long-standing target for antibiotic development against Gram-negative bacteria due to differences from the human FAS, and several existing antibacterial agents are known to inhibit FASII enzymes. N-Acetylcysteamine (NAC) fatty acid thioesters have been used as mimics of the natural acyl carrier protein pathway intermediates to assay FASII enzymes, and we now report an assay of FabV from Pseudomonas aeruginosa using (E)-2-decenoyl-NAC. In addition, we have converted an existing UV absorbance assay for FabA, the bifunctional dehydration/epimerization enzyme and key target in the FASII pathway, into a high-throughput enzyme coupled fluorescence assay that has been employed to screen a library of diverse small molecules. With this approach, N-(4-chlorobenzyl)-3-(2-furyl)-1H-1,2,4-triazol-5-amine (N42FTA) was found to competitively inhibit (pIC50=5.7±0.2) the processing of 3-hydroxydecanoyl-NAC by P. aeruginosa FabA. N42FTA was shown to be potent in blocking crosslinking of Escherichiacoli acyl carrier protein and FabA, a direct mimic of the biological process. The co-complex structure of N42FTA with P. aeruginosa FabA protein rationalises affinity and suggests future design opportunities. Employing NAC fatty acid mimics to develop further high-throughput assays for individual enzymes in the FASII pathway should aid in the discovery of new antimicrobials.

Nutritional and functional properties of Vicia faba protein isolates and related fractions

The goal of this research was the characterisation of Vicia faba (broadbean) protein isolates and related fractions in order to determine whether this grain legume could be used for production of high quality protein products and other fractions rich in functional components. Alkaline extraction of the defatted seed flour, followed by precipitation at the isoelectric pH, yielded a 92% protein isolate with a high oil absorption capacity. The contents of the favism-inducing glycosides, vicine and convicine, in the isolate were reduced by more than 99% as compared to the original flour, although the amino acid composition was similar to that of the flour. Some of the by-products of protein isolate production may also be of interest from a nutritional and functional point of view. Thus, the oil resulting from hexane extraction of the flour is rich in unsaturated fatty acids, and polyphenols (resulting from extraction of the defatted flour with acetone) showed a high ABTS radical-scavenging activity. In addition, the solid residue (resulting from protein solubilisation) was high in fibre and showed good water absorption. These results show good nutritional and functional properties in V. faba protein isolates and related fractions, which may favour the revalorisation of this traditional bean crop.

Computational Prediction of Properties and Analysis of Molecular Phylogenetics of Polyketide Synthases in Three Species of Actinomycetes

Polyketides are secondary metabolites of microorganisms synthesized by serialized reactions of a set of enzymes called polyketide synthases (PKS). As many infectious microorganisms are acquiring tolerance to antibiotics, the need for novel medicines is increasing. Recently, various methods are being used for drug discovery, including gene manipulation for biosynthesis of antibiotics such as polyketides. Due to their importance as drugs, the volume of data on polyketides is rapidly increasing. In the present paper, by using SEARCHPKS and ASMPKS servers, domain identification, and domain organization, substrate specificity of AT domain, domain assembly and chemical moiety of three Actinomycetes i.e., Mycobacterium abscessus, Micromonospora chalcea and Streptomyces achromogenes are analyzed. So far, no secondary metabolite of any of these bacteria is known. Here, it was demonstrated that KR1, KR2 and KR3 domains from M. chalcea, KR5 domain from M. abscessus and KR6 domain from S. achromogenes could be assigned as B1-type, while KR4 domain from M. abscessus and KR7 domain from S. achromogenes could be assigned as A1 type. Substrate specificity of AT1 and AT2 of M. abscessus predicted to be malonate. AT2 domain of PKS protein from S. achromogenes also selected as malonate. Methylmalonate substrate was predicted for AT1 and AT3 domains. All of the AT domains in modules of PKS protein of M. chalcea were predicted to be specific for methylmalonate. Analysis of folding rate of these proteins showed that the logarithm of (kf) decreased in proportion to protein chain length. We have also performed a comprehensive phylogenetics analysis of AT and DH domains with FabA, FabZ and dehydratase proteins of various bacteria and secondary metabolites. The phylogenetic tree derived from these sequences reflects the long joint evolution process.

Isolation of a Protein Interacting with Vfphot1a in Guard Cells of Vicia faba

A recent study has demonstrated that phototropins act as blue light receptors in stomatal guard cells. However, the downstream components responsible for phototropin signaling are largely unknown. In this study, using a yeast two-hybrid system, we isolated a Vicia faba protein that has a high similarity to dynein light chain in the C terminus, which interacts with Vicia faba phototropin 1a (Vfphot1a). Protein-blot and two-hybrid analyses revealed that Vfphot1a interacting protein (VfPIP) bound to the N-terminal [corrected] region of Vfphot1a but did not bind to Vfphot1b. The interaction between VfPIP and Vfphot was indicated by a pull-down assay. Northern analysis revealed that the transcription level of VfPIP gene was more abundant in guard cells than in other tissues or cell types. The transiently expressed fusion protein of VfPIP-green fluorescent protein was localized on cortical microtubules in Vicia guard cells. Microtubule-depolymerizing herbicides partially inhibited both blue light-dependent H(+) pumping in Vicia guard cell protoplasts and stomatal opening in the Vicia epidermis. From these results, we conclude that VfPIP may act as a downstream component of phototropin (Vfphot1a) in blue light signaling in guard cells. The possible role of VfPIP in blue light signaling of guard cells is discussed.

Functional Replacement of the FabA and FabB Proteins of Escherichia coli Fatty Acid Synthesis by Enterococcus faecalis FabZ and FabF Homologues

The anaerobic unsaturated fatty acid synthetic pathway of Escherichia coli requires two specialized proteins, FabA and FabB. However, the fabA and fabB genes are found only in the Gram-negative alpha- and gamma-proteobacteria, and thus other anaerobic bacteria must synthesize these acids using different enzymes. We report that the Gram-positive bacterium Enterococcus faecalis encodes a protein, annotated as FabZ1, that functionally replaces the E. coli FabA protein, although the sequence of this protein aligns much more closely with E. coli FabZ, a protein that plays no specific role in unsaturated fatty acid synthesis. Therefore E. faecalis FabZ1 is a bifunctional dehydratase/isomerase, an enzyme activity heretofore confined to a group of Gram-negative bacteria. The FabZ2 protein is unable to replace the function of E. coli FabZ, although FabZ2, a second E. faecalis FabZ homologue, has this ability. Moreover, an E. faecalis FabF homologue (FabF1) was found to replace the function of E. coli FabB, whereas a second FabF homologue was inactive. From these data it is clear that bacterial fatty acid biosynthetic pathways cannot be deduced solely by sequence comparisons.

Identification of proteins of Escherichia coli and Saccharomyces cerevisiae that specifically bind to C/C mismatches in DNA

The pathways leading to G:C-->C:G transversions and their repair mechanisms remain uncertain. C/C and G/G mismatches arising during DNA replication are a potential source of G:C-->C:G transversions. The Escherichia coli mutHLS mismatch repair pathway efficiently corrects G/G mismatches, whereas C/C mismatches are a poor substrate. Escherichia coli must have a more specific repair pathway to correct C/C mismatches. In this study, we performed gel-shift assays to identify C/C mismatch-binding proteins in cell extracts of E. COLI: By testing heteroduplex DNA (34mers) containing C/C mismatches, two specific band shifts were generated in the gels. The band shifts were due to mismatch-specific binding of proteins present in the extracts. Cell extracts of a mutant strain defective in MutM protein did not produce a low-mobility complex. Purified MutM protein bound efficiently to the C/C mismatch-containing heteroduplex to produce the low-mobility complex. The second protein, which produced a high-mobility complex with the C/C mismatches, was purified to homogeneity, and the amino acid sequence revealed that this protein was the FabA protein of E.COLI: The high-mobility complex was not formed in cell extracts of a fabA mutant. From these results it is possible that MutM and FabA proteins are components of repair pathways for C/C mismatches in E.COLI: Furthermore, we found that Saccharomyces cerevisiae OGG1 protein, a functional homolog of E.COLI: MutM protein, could specifically bind to the C/C mismatches in DNA.

Functional properties of faba bean ( Vicia faba) protein flour dried by spray drying and freeze drying

Faba protein flour of Vicia faba was obtained by precipitation and centrifugation from peeled and milled seeds. The flour was dried by spray drying and freeze drying. The effect of both methods of drying on functional properties such as solubility, emulsification, water retention, viscosity and enzymatic hydrolysis was studied.

Hypocholesterolemic effect of a Vicia faba protein concentrate in hypercholesterolaemic rats

Hypocholesterolemic effect of a Vicia faba protein concentrate in hypercholesterolaemic rats

Nutritional Assessment of Raw and Processed Faba Bean (Vicia faba L.) Cultivar Major in Growing Rats

We tested the effects of several processing methods on the nutritional value of faba beans. Nutritional assessment was based on chemical analyses of legume protein content and on the digestive and metabolic utilization in rats. Protein content in Vicia faba (V. faba) was 28%, and the supply of essential amino acids, except for sulfur-containing acids, was sufficient to cover the rat's nutritional requirements. Food intake was significantly lower in animals fed with raw faba beans than in the control group given the casein diet. We attribute this to the deficient levels of some amino acids and the presence of antinutritional factors (α-galactosides and tannins) in faba beans. All processing methods except heating under pressure increased food intake. The digestive utilization of V. faba protein was high, although lower than that of the casein diet. This may be related to the presence of protease inhibitors and tannins in faba beans. Nitrogen retention was similar in control animals and rats fed with raw be...