Nutrient digestibility of chickpea (Cicer arietinum L.) seeds and effects on the small intestine of weaned piglets

The Effect of a Diet Containing Extruded Faba Bean Seeds on Growth Performance and Selected Microbial Activity Indices in the Large Intestine of Piglets

Simple Summary

Grain legumes are cultivated for food and feed purposes in all regions of the world. Legumes are the main source of protein for a large part of the world population where animal protein is hardly available. The potential of grain legumes is increasing primarily due to the genetic improvement of their agricultural and nutritional characteristics and expansion of organic farming. They are also fed to animals as a component of concentrates and on farms producing “organic” food. Therefore, studies on the composition, nutritional value and factors affecting quality of legume protein contribute to a more efficient utilization of seeds as feed and food ingredients. Faba bean is rich in both starch and protein and is an important alternative protein source in animal nutrition; however, its potential is not yet fully exploited, particularly in pig diets. The aim of the study was to evaluate the effect of diets containing various levels of extruded faba bean seeds on growth performance and selected microbial activity indices in the large intestine of pigs. Treatments with faba bean seeds did not negatively affect growth performance (except for the highest level of faba bean) and microbial activity in the large intestine, and can be applied in piglet diets.

Abstract

The study investigated the effect of replacing soybean meal with extruded faba bean seeds on piglet growth performance and selected microbial activity indices in the large intestine. In total, 24, 35-day-old, healthy, castrated piglets of similar body weight were divided into four groups with six replicates. Animals in the control group (C) were fed with soybean meal without extruded faba bean seeds. In other experimental groups, pigs were fed diets with the addition of 20 (FB20), 25 (FB25) or 30% (FB30) extruded faba bean seeds instead of soybean meal and wheat starch. Growth performance, histology of the large intestine, short-chain fatty acids (SCFA) and ammonia concentration, as well as the activity of bacterial enzymes in digesta samples, were analyzed. The intake of the FB25 diet resulted in an increased feed:gain ratio in comparison to the FB30 group. Feeding the FB30 diet increased tunica muscularis thickness in the caecum as compared to other groups. Moreover, dietary inclusion of extruded faba bean seeds had no effect on SCFA and ammonia concentration. In addition, feeding diets with a different level of extruded faba bean seeds did not affect the activity of bacterial enzymes in the colon.

Food processing for the improvement of plant proteins digestibility

Proteins are essential macronutrients for the human diet. They are the primary source of nitrogen and are fundamental for body structure and functions. The plant protein quality (PPQ) refers to the bioavailability, digestibility, and amino acid composition. The digestibility specifies the protein quantity absorbed by an organism relative to the consumed amount and depends on the protein structure, previous processing, and the presence of compounds limiting the digestion. The latter are so-called antinutritional factors (ANF), exemplified by phytates, tannins, trypsin inhibitors, and lectins. Animal proteins are known to have better digestibility than plant proteins due to the presence of ANF in plants. Thus, the inactivation of ANF throughout food processing may increase the PPQ. New food processing, aiming to increase the digestibility of plant proteins, and new sources of proteins are being studied for the animal protein substitution. Here, it is presented the impact of processing on the protein digestibility and reduction of ANF. Several techniques, such as cooking, autoclaving, germination, microwave, irradiation, spray- and freeze-drying, fermentation, and extrusion enhanced the PPQ. The emerging non-thermal technologies impact on protein functionalities but require studies on the protein digestibility. How to accurately determine and how to improve the protein digestibility of a plant source remains a scientific and technological challenge that may be addressed by novel or combining existing processing techniques, as well as by exploring protein-enriched by-products of the food industry.

Characterisation of the bioactive properties and microstructure of chickpea protein-based oil in water emulsions

Legumes, such as chickpea, represent a good source of high quality proteins for which there is an increasing global consumer demand. A chickpea protein concentrate (CP) was generated by isoelectric precipitation. Protein determination, electrophoretic and gel permeation chromatographic analysis revealed that the order of CP solubility was pH 7.5 > 2.5 > 5.0. Sunflower oil in water (O/W) emulsions were generated with the CP at pH 2.5, 5.0 and 7.5. Microstructural evaluation of the emulsions using laser light-scattering particle size analysis, optical microscopy and rheological analysis showed that smaller droplet size (3.1 ± 0.2 and 1.1 ± 0.1 μm) and the highest elastic moduli (876.0 ± 3.2 and 563.5 ± 6.5 Pa) were obtained in those emulsions generated with CP at pH 2.5 and 7.5. The ferric reducing (FRAP) and oxygen radical absorbance capacity (ORAC) values of the CP emulsions ranged from 194.5 ± 19.2 to 242.4 ± 8.4 μmol Trolox Eq·g^-1 CP for FRAP at pH 2.5 and 5.0, respectively, and from 313.2 ± 2.6 to 369.0 ± 1.6 μmol Trolox eq·g^-1 CP for ORAC at pH 5.0 and 2.5, respectively. The enzyme inhibitory activity of the emulsions was generally low irrespective of the pH value (c.a. 3 and 30% inhibition for dipeptidyl peptidase IV (DPP-IV) and angiotensin converting enzyme (ACE) activity, respectively). Simulated gastrointestinal digestion (SGID) of the emulsions significantly decreased their FRAP whereas it increased their ORAC values as well as their ACE and DPP-IV inhibitory activities irrespective of the pH value of the CP. These results demonstrate the potential application of reduced fat CP-stabilized emulsions for the provision of antioxidant and enzyme inhibitory activities.

Fasting and refeeding modulate the expression of stress proteins along the gastrointestinal tract of weaned pigs

The gastrointestinal tract (GIT) of young mammals is submitted to aggressions early in life and GIT stress proteins are up-regulated in pigs following weaning. We hypothesized that transient food deprivation may contribute to these changes. Therefore, the effects of fasting and refeeding on GIT stress proteins in weaned pigs were investigated. A complete block experimental design with three groups of five pigs each was set up with the following treatments: A - food offered, B - fasted for 1.5 days, C - fasted for 1.5 days and then re-fed for 2.5 days. After slaughter, the GIT was removed, weighed and sampled. Intestinal villi and crypts were measured and alkaline phosphatase activity was determined. GIT tissue stress protein concentrations were measured by Western blotting. Fasting led to intestinal mucosa and villous-crypt atrophy (p < 0.01) and reduced mucosal alkaline phosphatase total activity in the proximal small intestine (p < 0.05). Heat shock proteins HSP 27 and HSP 90 (but not HSP 70) and neuronal NO synthase (nNOS) increased (p < 0.01) in the stomach, mid-intestine and proximal colon with fasting. Inducible NOS (iNOS) did so in the stomach (p < 0.001). Refeeding partially or totally restored GIT characteristics and stress protein concentrations, except for gastric HSP 90 and iNOS. Significant correlations (p < 0.05 to p < 0.0001) were found among stress proteins, between nNOS and digesta weight, between HSP 27 or HSP 90 and intestinal mucosa weight, and between intestinal or colonic HSP or nNOS and alkaline phosphatase. In conclusion, fasting and refeeding modulate GIT HSP proteins and nNOS in pigs following weaning. Changes in digesta and intestinal mucosa weights and alkaline phosphatase activity may be involved in the modulation of stress proteins along the GIT.

Methods for mucin analysis: a comparative study

The aim was to compare five techniques commonly used to quantify mucin concentrations in ileal digesta collected from three growing pigs that had been fed a diet in which the sole protein was casein. Ileal mucin output was estimated by the periodic acid-Schiff, ethanol precipitation, and phenol-sulfuric acid methods as 25.1, 19.3, and 20.7 g kg-1 of dry matter intake (DMI), respectively. The mucin concentration estimated from sialic acid was only 5.9 g kg-1 of DMI. On the basis of the concentrations of the hexosamines N-acetylglucosamine and N-acetylgalactosamine, mucin output was estimated as 44.9 g kg-1 pf DMI. Of the five assays studied, the ethanol precipitation, periodic acid-Schiff, phenol-sulfuric acid, and sialic acid methods may considerably underestimate mucin in the digesta, which calls into question the accuracy of all of these approaches. In contrast, the gas chromatography method for the determination of hexosamines gave more information on the type and state of the mucin present.

Intestinal physiology and peptidase activity in male pigs are modulated by consumption of corn culture extracts containing fumonisins

Fumonisin B(1) (FB1) alters intestinal epithelial cell cycle and absorptive, secretory, and barrier properties in vitro, but in vivo data are lacking. Therefore, we tested the hypothesis that repeated intake of a corn culture extract rich in fumonisins, mainly in FB1, alters indices of intestinal absorptive and secretory physiology and barrier function in vivo. Intra-litter pairs of pigs (n = 36) weaned at 28 d, were fed the vehicle (control) or the extract (providing 1.5 mg FB1/kg body weight) daily for 9 d starting 7 d postweaning. After slaughter, the jejunal mucosa of pigs was mounted in Ussing chambers (UC). Extract consumption for 9 d decreased the gain:feed ratio (P = 0.04) and increased liver weight (P = 0.01). Basal net ion secretion (P = 0.02), sodium-dependent glucose absorption (P = 0.02), and theophylline-induced secretion (P < 0.01) of the jejunal mucosa determined in UC were higher in pigs fed the extract than in controls. By contrast, jejunal permeability to the horseradish peroxidase model protein in UC was not influenced by extract consumption. Ileal villi tended to be longer (P = 0.07) and jejunal aminopeptidase N activity was lower (P < 0.01) in pigs fed the extract. In conclusion, consumption of an extract rich in fumonisins for 9 d has the potential to alter intestinal physiology, villous architecture, and enzyme activities. Underlying mechanisms remain to be investigated.

Endogenous components of digesta protein from the terminal ileum of pigs fed a casein-based diet

To gain a clearer understanding of the nature and composition of endogenous nitrogen containing substances lost from the upper mammalian digestive tract, digesta were collected from the terminal ileum of six growing pigs that had been fed a casein-based diet with titanium dioxide as an indigestible marker. Total nitrogen lost at the terminal ileum was in excess of 63 mg.g(-1) digesta dry matter. Of this, nearly 73% was proteinaceous, with nearly 45% being bacterial protein, 13% from soluble free protein, and 11% from mucin. Of the nonprotein nitrogen, 11% was as ammonia and 5% as urea. Bacterial and porcine cellular DNA nitrogen were collectively 0.2% of the total nitrogen. Only 8.3% of the total nitrogen remained unidentified and was assumed to include free amino acids, RNAs, amines, and the tetrapyrroles bilirubin and biliverdin. Although mucin contributed just 10.4% of the nitrogen losses, it was the single most abundant truly endogenous component, comprising 13% of the total dry matter. Bacterial nitrogen, combined with ammonia and urea nitrogen, represented nearly 61% of the total nitrogenous losses: this suggests substantial microbial activity in the stomach and small intestine of the pig. Centrifugal separation of a bacterial fraction from the digesta produced a microbial amino acid profile that, when subtracted from the overall amino acid content, provided an amino acid profile more representative of true endogenous amino acid losses.

Nutritional responses of rats to diets based on chickpea ( Cicer arietinum L.) seed meal or its protein fractions

The aim of this study was to isolate the protein fractions from chickpea, var. IAC-Marrocos, as well as to evaluate its in vivo nutritional protein quality. Among the proteins, albumins showed better nutritional value in the in vivo assays and amino acid contents, despite their higher trypsin inhibitor contents. Trypsin inhibitors were found to be heat labile in all samples, but the digestibility results for unheated and heated flour and albumins suggest that their contents are not very decisive. The PER values for casein (not supplemented) were very similar to those of heated flour and unheated or heated albumin and total globulins. The albumin and glutelin fractions showed the best results for PDCAAS, however, lower than those of casein. Despite the high digestibility of the globulin the very low essential amino acid content lowered its PDCAAS, and it had the lowest values.

Influence of thePhaseolus vulgarisphaseolin level of incorporation, type and thermal treatment on gut characteristics in rats

Phaseolus vulgarisphaseolin has been shown to stimulate faecal losses of endogenous N in rats. Experiments with purified phaseolin were carried out in rats to test the hypothesis that these losses reflect intestinal disorders. Phaseolin composition varies depending on its constitutive subunits. Therefore, three phaseolin types (S, T, I) were tested. Phaseolin T was incorporated in varying levels (0, 33, 67 or 100% of the dietary protein) as raw material in experiment 1. In experiment 2, the three phaseolin types were incorporated at 50%, with or without previous thermic treatment. Raw casein was the basal protein source and was also heated in experiment 2. Faecal digestibility of phaseolin and gut integrity were evaluated in both experiments. The incorporation level or type of phaseolin had little effect on gross anatomy of gut segments but these factors influenced the weight and pH of fresh contents of the stomach and caecum (P<0·05). Raw phaseolin T incorporated at various levels led to an enlargement of duodenal villi together with a tendency for increased crypt depth in the jejunum (P=0·06). Activities of both alkaline phosphatase in the duodenum and aminopeptidase N in the ileum decreased (P<0·05) after thermal treatment of casein while they increased (P<0·05) for heat-treated phaseolin S and T, respectively. In conclusion, raw phaseolin had no effect on the tissue weight of gut segments and induced limited alterations in the small intestine. Differences due to phaseolin level or type were limited too.

Legume grains enhance ileal losses of specific endogenous serine-protease proteins in weaned pigs

Feeding legume grains to pigs usually increases losses of endogenous proteins at the terminal ileum. However, the identity of such proteins is largely unknown. This study was undertaken to determine the ileal flow and identity of soluble proteins present in large concentrations in ileal digesta of young pigs fed soybean meal (SBM), peas (P), faba beans (FB), or blue lupin (L) in expt. 1, and white (WPC) or black (BPC) chickpeas in expt. 2. Protein in the control diet (C) was provided by casein. Ileal digesta proteins were analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis, Coomassie blue staining, densitometry and N-terminal amino acid sequencing. Three protein bands at molecular masses of 25, 27, and 30 kDa had a higher ileal flow (P < 0.05) in the pigs fed the legume-based diets compared to those fed the control diet in expt. 2. This was true for the 25- and 30-kDa proteins (P < 0.05) and the 27-kDa protein (P < 0.10) in pigs fed the legume-containing diets in expt. 1. These proteins shared N-terminal amino acid sequences with enzymes of the serine protease family including pig trypsin (25 kDa) and blood coagulation factor IX or chymotrypsin (27 and 30 kDa).