High Protein Fraction Research Articles

Role of genetic variant GC gene to vitamin D deficiency in Indonesian population

High dietary protein and the use of poorly digested protein sources have been suggested to negatively impact broiler health, possibly because of protein fermentation in the distal intestinal tract. The effect of dietary protein levels with low or high indigestible protein fractions (LIP or HIP) on male and female broiler performance were evaluated. The trial was completely randomized with a 2 × 3 × 2 factorial arrangement, where gender, dietary protein levels (24, 26, and 28%), and dietary protein digestible fractions were the main factors. Ross 308 male (1944) and female (2232) were allocated to 72 pens with 54 males or 62 females per pen. Six grower diets 24-LIP, 24-HIP, 26-LIP, 26-HIP, 28-LIP, and 28-HIP were fed from 0 to 32 D of age. Birds were vaccinated with Coccivac-B52 on day 5, and feed intake and BW were recorded on 0, 12, 22, and 32 D. On day 32, 24 birds per treatment were processed for meat yield. Males were heavier than females at all post-hatch ages and the LIP birds were heavier than their HIP counterparts on 32 D. On day 22, birds fed 24 and 26% CP were heavier than those fed 28% CP. Birds fed the 28-LIP diet consumed less total feed than their 24 and 26-LIP equivalents. Birds fed 24% CP had the highest total feed to gain ratio, whereas LIP fed birds had a lower total feed to gain than those fed HIP diets. LIP diets resulted in higher total mortality than the HIP diets. Carcass yield was higher for females than males, increased with CP level, and was lower in HIP than LIP birds. An interaction between CP level and protein digestibility resulted in the 26 and 28-LIP having higher breast yield than all other diets. In conclusion, broiler growth performance and meat yield were affected by dietary indigestible protein alone or in combination with gender and dietary CP level.

Mixed culture purple phototrophic bacteria is an effective fishmeal replacement in aquaculture

Aquaculture is the fastest growing animal food production industry, now producing 50% of all food fish. However, aquaculture feeds remain dependent on fishmeal derived from capture fisheries, which must be reduced for continued sustainable growth. Purple phototrophic bacteria (PPB) efficiently yield biomass from wastewater with high product homogeneity, a relatively high protein fraction, and potential added value as an ingredient for fish feeds. Here we test bulk replacement of fishmeal with PPB microbial biomass in diets for Asian sea bass (Lates calcarifer), a high value carnivorous fish with high protein to energy requirement. Mixed culture PPB were grown in a novel 1 m3 attached photo-biofilm process using synthetic and real wastewater. Four experimental diets were formulated to commercial specifications but with the fishmeal substituted (0%, 33%, 66%, and 100%) with the synthetic grown PPB biomass and fed to a cohort of 540 juvenile fish divided amongst 12 tanks over 47 days. Weight and standard length were taken from individual fish at 18, 28, and 47d. No significant difference in survival was observed due to diet or other factors (94–100%). There was a negative correlation between PPB inclusion level and final weight (p = 5.94 × 10−5) with diet accounting for 4.1% of the variance over the trial (general linear model, R2 = 0.96, p = 1 × 10−6). Feed conversion ratio was also significantly influenced by diet (p = 6 × 10−7) with this factor accounting for 89% of variance. Specifically, feed conversion ratio (FCR) rose to 1.5 for the 100% replacement diet during the last sample period, approximately 1.0 for the partial replacement, and 0.8 for the nil replacement diet. However, this study demonstrates that bulk replacement of fishmeal by PPB is feasible, and commercially viable at 33% and 66% replacement.

Identification of Levels of Serum Amyloid A and Apolipoprotein A1 in Serum Proteomic Analysis of Neuropsychiatric Systemic Lupus Erythematosus Patients.

Neuropsychiatric Systemic Lupus Erythematosus (NPSLE) has multiple pathogenic mechanisms that cause diverse manifestations and whose diagnosis is challenging because of the absence of appropriate diagnostic tests. In the present study the application of proteomics using two-dimensional electrophoresis (2D) and mass spectrometry (MS) allowed the comparison of the protein profile of the serum low and high abundance protein fractions of NPSLE patients (NPSLE group) and SLE without neuropsychiatric syndromes (SLE group), Neuropsychiatric syndromes not associated with SLE (NPnoSLE groups), and healthy controls (CTRL group). The gels obtained were digitalized and analyzed with the PDQuest software. The statistical analysis of the spots was performed using the nonparametric Kruskal Wallis and Dunn's multiple comparison tests. Two spots showed significant differences and were identified by MS. Spot 4009 was significantly lower in NPSLE with regard to NPnoSLE (p= 0,004) and was identified as apolipoprotein A1 (APOA1) (score 809-1132). Spot 8001 was significantly higher in NPSLE regarding CTRL and NPnoSLE (p= 0,01 y 0,03, respectively) and was identified as serum amyloid A (SAA) (score 725-2488). The proinflammatory high density lipoproteins (HDL) have been described in SLE. In this HDL the decrease of APOA1 is followed by an increase in SAA. This altered level of both proteins may be related to the inflammatory state that is characteristic of an autoimmune disease like SLE, but this is not specific for NPSLE.

Tail-end dehulling of canola meal improves apparent and standardized total tract digestibility of phosphorus when fed to growing pigs.

Tail-end dehulling of canola meal (CM) has been shown to reduce dietary fiber and increase crude protein content in the dehulled meal. The application of this procedure also increased the total and non-phytate P content in the dehulled meal. However, it is unclear if dehulling affects P digestibility in the different fractions (i.e., the dehulled meal and the coarse fraction) and if it differs when fed to growing pigs at two different BW. Therefore, two experiments were conducted to determine the apparent (ATTD) and standardized (STTD) total tract digestibility of P in dehulled CM fed to growing pigs. Diets containing non-dehulled regular canola meal (RCM), and two fractions produced using sieve size of 355 µm: a low-fiber high-protein fraction (dehulled canola meal [DCM]) and a high-fiber low-protein fraction (coarse canola meal [CCM]) as the only source of P were fed to growing pigs at two different BW. A total of 48 pigs were used for the two experiments. In experiment 1, 24 barrows [(Yorkshire × Landrace) × Duroc] with initial BW of 24.5 ± 1.68 kg were individually housed in metabolism crates and fed the experimental diets for 10 d for total fecal collection. In experiment 2, 24 barrows with an average initial BW of 73.8 ± 4.93 kg were used; experimental diets and fecal collection procedures were the same as in experiment 1. Each experiment used six replicates per treatment. A P-free diet was used to determine basal endogenous losses of P (139.6 ± 10.7 and 150.89 ± 20.1 mg/kg of DMI for experiments 1 and 2, respectively). Data were analyzed as a completely randomized design. In experiment 1, the ATTD and STTD of P were greater (P < 0.05) for DCM (42.4% and 46.1%) than for the RCM (32.0% and 35.7%) and CCM (24.5% and 28.4%) diets. In experiment 2, the ATTD and STTD of P were greater (P < 0.05) for DCM (38.7% and 42.8%) than for the CCM diet (22.6% and 26.8%); whereas the values for RCM diet were intermediate (31.0% and 35.0%) and not different from the DCM and CCM. In conclusion, dehulling canola meal increased ATTD and STTD of P in growing pigs of different BW; however, there was no effect of BW.

Monoclonal protein reference change value as determined by gel-based serum protein electrophoresis

IntroductionThe International Myeloma Working Group recommendations for monitoring disease progression or response include quantitation of the involved monoclonal immunoglobulin. They have defined the minimum change criteria of ≧25% with an absolute change of no <5g/L for either minimal response or progression. Limited evidence is available to accurately determine the magnitude of change in a monoclonal protein to reflect a true change in clinical status. Here we determined the analytical and biological variability of monoclonal proteins in stable monoclonal gammopathy of undetermined significance (MGUS) patients. MethodAnalytical variability (CVa) of normal protein fractions and monoclonal proteins were assessed agarose gel-based serum protein electrophoresis. Sixteen clinically stable MGUS patients were identified from our clinical hematology database. Individual biological variability (CVi) was determined and used to calculate a monoclonal protein reference change value (RCV). ResultAnalytical variability of the normal protein fractions (albumin, alpha-1, alpha-2, beta, total gamma) ranged from 1.3% for albumin to 5.8% for the alpha-1 globulins. CVa of low (5.6g/L) and high (32.2g/L) concentration monoclonal proteins were 3.1% and 22.2%, respectively. Individual CVi of stable patients ranged from 3.5% to 24.5% with a CVi of 12.9%. The reference change value (RCV) at a 95% probability was determined to be 36.7% (low) 39.6% (high) using our CVa and CVi. ConclusionsSerial monitoring of monoclonal protein concentration is important for MGUS and multiple myeloma patients. Accurate criteria for interpreting a change in monoclonal protein concentration are required for appropriate decision making. We used QC results and real-world conditions to assess imprecision of serum protein fractions including low and high monoclonal protein fractions and clinically stable MGUS patients to determine CVi and RCV. The calculated RCVs of 36.7% (low) and 39.6% (high) in this study were greater that reported previously and greater than the established criteria for relapse. Response criteria may be reassessed to increase sensitivity and specificity for detection of response.

Distribution of β-amylase and lipoxygenase in soy protein products obtained during tofu production

Soybean is considered an important source of human food and animal feed. Okara and tofu whey are the main by-products of soymilk and tofu production. The distribution of enzymes ?-amylase and lipoxygenase (Lox) from six soybean genotypes in protein extracts of okara and tofu as well as in soymilk and tofu whey was assessed. SDS-electrophoretic results showed that production process significantly affected high molecular mass protein fractions of soybean by-products. Low amounts of Lox in soymilk were registered, while in okara protein extracts and tofu whey this enzyme was present in trace. In tofu protein extracts, Lox was registered in higher quantity that might be the result of the aggregation process during formation of the tofu gel. Content of ?-amylase in all soy protein products was high and similar to the content in soybean genotype. Content of ?-amylase in okara depended on respective soybean genotype.

The selective complex behavior between soybean whey proteins and ι-carrageenan and isolation of the major proteins of the soybean whey

Proteins in soybean whey were separated into two groups by graded salt precipitation, low and high isoelectric point protein fractions (LIP and HIP), corresponding to the mixture of Kunitz trypsin inhibitor (KTI) and Bowman–Birk protease inhibitor (BBI) as well as the mixture of soybean agglutinin (SBA) and β-amylase, respectively. The complex behavior of LIP and HIP with ι-carrageenan (CG) as a function of pH (7.0–2.0) and protein-polysaccharide mass mixing ratio (1:1 to 20:1, w/w) was studied by turbidimetric titration and SDS-PAGE. During pH titration, pHϕ1 (the initial pH for the formation of insoluble complexes) and pHmax (the pH for maximum optical density) showed mixing ratio dependence so that the choice of mixing ratio determined the order of coacervation. SDS-PAGE results showed that at protein/polysaccharides mass ratio (Rpr/ps) of ≥15:1, just only KTI (or SBA) complex with ι-carrageenan and shift to precipitates after centrifugation, BBI (or β-amylase) was kept in supernatant. This selectivity was also independent of the total biopolymer concentration (Cp) and titration path. After removal of carrageenan, high-purity KTI, BBI and SBA (over 90% by SEC-HPLC) were obtained. Isothermal titration calorimetry (ITC) showed that, the smaller thermodynamic stoichiometry (n) with higher thermodynamic constants (K) was observed when KTI (or SBA) complexing with CG compared to BBI (or β-amylase). The higher surface charge density of KTI (+0.22 × 10−2 C/m2) and SBA (+0.14 × 10−2 C/m2) may contribute partly to their higher CG thermodynamic affinity.

Array-Based Two Dimensional Liquid Chromatography System for Proteomic Analysis of Human Plasma

Abstract The human plasma proteome has the characteristics of complexity in component and large dynamic range of protein concentrations. Herein, an array-based online two dimensional liquid chromatography system combined with protein equalizer technology was developed for the large-scale depletion of high abundance proteins and enrichment of low abundance proteins in human plasma. The array-based online two dimensional liquid chromatography system could be used to separate the plasma at the intact protein level with good reproducibility and high throughput. The total separation time was only 4 h and the fast location of high abundance proteins was also achieved. After the high abundance protein fractions was treated by ampholine@PM polymer microsphere, the number of identified low abundance proteins increased ten-fold, which significantly decreased the loss of low abundance proteins in high abundance protein fractions. The techniques combined were then applied to perform the proteomic analysis of human plasma sample. The total number of identified proteins was 1474 and the dynamic range of protein concentration was 7. In this work, 252 proteins were identified in high abundance protein fractions, among which 61 proteins belonged to high abundance proteins. These results demonstrated that an array-based online two dimensional liquid chromatography system combined with protein equalizer technology could efficiently achieve the large-scale depletion of high abundance proteins and the enrichment of low abundance proteins in human plasma, with a remarkable improvement in protein identification and a great prospect in the proteomic research of other complex samples.

Salinity induced physiological and biochemical changes in chickpea (Cicer arietinum L.) genotypes

Plant growth and development are adversely affected by salinity- a major environmental stress that limits agricultural production. Chickpea (Cicer arietinum L.) is sensitive to salinity that affects its yield and there is need to identify the tolerant genotypes. The present study was conducted to evaluate the effect of salinity on chickpea genotypes with specific physiological and biochemical attributes contributing to their adaptability to salinity stress. Seven chickpea genotypes both desi (ICC8950, ICCV10, ICC15868, GL26054) and kabuli (BG1053, L550, L552) were evaluated for salinity tolerance. Maximum decrease in relative leaf water content and chlorophyll content was observed with ICC15868 and GL26054 among the desi and L552 from the kabuli genotypes. The photosynthetic pigments, activity of nitrate reductase and relative leaf water content was also reduced in response to salt application with effect being more pronounced in ICC15868, GL26054 and L552 as compared to ICC8950, ICCV10, BG1053 and L550. Lipid peroxidation increases with the increase in NaCl concentration, maximum increment was observed in genotypes ICC15868, GL26054 and L552. Accumulation of proline in response to environmental stresses seems to be widespread among plants. Higher protein fractions were observed with tolerant genotypes in contrast to sensitive genotypes. Salt imposed stress finally caused a higher decline in number of filled pods. On the basis of physiological and biochemical parameters genotypes ICC8950 and ICCV10 from the desi genotypes and BG1053 and L550 from kabuli were identified as the tolerant while ICC15868, GL26054 as the sensitive ones and L552 as the moderately tolerant genotypes. These genotypes could be used as a source of tolerance in breeding programme to develop salt tolerant genotypes.

Texturized pinto bean protein fortification in straight dough bread formulation.

Pinto beans were milled and then air-classified to obtain a raw high protein fraction (RHPF) followed by extrusion to texturize the protein fraction. The texturized high protein fraction (THPF) was then milled to obtain flour, and combined with wheat flour at 5, 10, and 15% levels to make bread. The air-classification process produced flour with high concentration of lipids and phytic acid in the protein-rich fraction. However, extrusion significantly reduced hexane extractable lipid and phytic acid. However, the reduction observed may simply indicate a reduction in recovery due to bind with other components. Total protein and lysine contents in composite flours increased significantly as THPF levels increased in composite flour. Bread made with 5% THPF had 48% more lysine than the 100 % wheat flour (control). The THPF helped to maintain dough strength by reducing mixing tolerance index (MTI), maintaining dough stability and increasing departure time on Farinograph. Bread loaf volume was significantly reduced above 5% THPF addition. THPF increased water absorption causing an increase in bread weights by up to 6%. Overall, loaf quality deteriorated at 10 and 15% THPF levels while bread with 5% THPF was not significantly different from the control. These results support the addition of 5% THPF as a means to enhance lysine content of white pan bread.

Fractionation of Distillers Dried Grains with Solubles (DDGS) Through a Narrowing of Particle Size Distribution Followed by Aspiration

Distiller's dried grains with solubles (DDGS) may have more value and utility if they can be separated into high protein and high fiber fractions. A variety of such separation processes have been proposed; two of the most promising processes involve three screening and three air classification unit operations. In the present study, an alternative process involving fewer unit operations is demonstrated. DDGS are subjected to a single screening, and the oversize particles are processed in a mill setup so that it narrows the particle size distribution of the oversize fraction. The milled DDGS is then processed in an air classification device known as an aspirator, which separates it into high and low terminal velocity fractions. The combination of the undersize fraction and the low terminal velocity fraction were substantially enriched in protein. The separation achieved by this process compares favorably to other reported processes while being less complex.

Relationships of Quality Characteristics with Size‐Exclusion HPLC Chromatogram of Protein Extract in Soft White Winter Wheats

ABSTRACTThis study investigated relationships between molecular weight distributions of unreduced grain proteins and grain, flour, and end‐use quality characteristics of soft white winter wheats grown in Oregon. Absorbance area and area percentage values of protein fractions separated by size‐exclusion HPLC (SE‐HPLC) showed significant correlations with quality characteristics, indicating associations of molecular weight distributions of proteins with quality characteristics. Specifically, high molecular weight polymeric protein fractions appeared to have a detrimental effect on soft wheat quality. This was shown by significant positive correlations with single kernel hardness index, and mixograph water absorption and tolerance, and negative correlations with break flour yield, cookie diameter, and cake volume. Higher proportions of soluble monomeric protein fraction eluted after the main gliadin peak, were associated with soft wheat quality due to negative associations with single kernel hardness index and mixograph water absorption and tolerance, and positive associations with break flour yield, cookie diameter, and cake volume. Calibration models were developed by the application of multivariate analyses to the SE‐HPLC data. These models explained &gt;90% of the variation in mixograph water absorption and cookie diameter and thickness.

Solution Structure of the DNA Binding Domain of Rice Telomere Binding Protein RTBP1,

RTBP1 is a rice telomeric protein that binds to the duplex array of TTTAGGG repeats at chromosome ends. The DNA binding domain of RTBP1 contains a Myb-type DNA binding motif and a highly conserved C-terminal Myb extension that is unique to plant telomeric proteins. Using an electrophoretic mobility shift assay, we identified the C-terminal 110-amino acid region (RTBP1(506-615)) as the minimal telomeric DNA binding domain, suggesting that the Myb extension is required for binding plant telomeric DNA. Like other telomeric proteins such as human TRF1 and yeast Rap1, RTBP1 induced a DNA bending in the telomeric repeat sequence, suggesting that RTBP1 may play a role in establishing and/or maintaining an active telomere configuration in vivo. To elucidate the DNA binding mode of RTBP1, we determined the three-dimensional structure of RTBP1(506-615) in solution by NMR spectroscopy. The overall structure of RTBP1(506-615) is composed of four alpha-helices and stabilized by three hydrophobic patches. The second and third helices in RTBP1 form a helix-turn-helix motif that interacts directly with DNA. The fourth helix located in the Myb extension is essential for binding to telomeric DNA via stabilization of the overall structure of the RTBP1 DNA binding domain. When DNA bound to RTBP1(506-615), large chemical shift perturbations were induced in the N-terminal arm, helix 3, and the loop between helices 3 and 4. These results suggest that helix 3 functions as a sequence-specific recognition helix while the N-terminal arm stabilizes the DNA binding.

Albumin Is the Main Nucleophilic Target of Human Plasma: A Protective Role Against Pro-atherogenic Electrophilic Reactive Carbonyl Species?

The aim of this work was to study the metabolic fate of 4-hydroxy- trans-2-nonenal (HNE) in human plasma, which represents the main vascular site of reactive carbonyl species (RCS) formation and where the main pro-atherogenic target proteins are formed. When HNE was spiked in human plasma, it rapidly disappeared (within 40 s) and no phase I metabolites were detected, suggesting that the main fate of HNE is due to an adduction mechanism. HNE consumption was then monitored in two plasma fractions: low molecular weight plasma protein fractions (<10 kDa; LMWF) and high molecular weight plasma protein fractions (>10 kDa; HMWF). HNE was almost stable in LMWF, while in HMWF it was consumed by almost 70% within 5 min. Proteomics identified albumin (HSA) as the main protein target, as further confirmed by a significantly reduced HNE quenching of dealbuminated plasma. LC-ESI-MS/MS analysis identified Cys34 and Lys199 as the most reactive adduction sites of HSA, through the formation of a Michael and Schiff base adducts, respectively. The rate constant of HNE trapping by albumin was 50.61 +/- 1.89 M (-1) s (-1) and that of Cys34 (29.37 M (-1) s (-1)) was 1 order of magnitude higher with respect to that of GSH (3.81 +/- 0.17 M (-1) s (-1)), as explained by molecular modeling studies. In conclusion, we suggest that albumin, through nucleophilic residues, and in particular Cys34, can act as an endogenous detoxifying agent of circulating RCS.

Exopolysaccharides produced by the recently described halophilic bacteria Halomonas ventosae and Halomonas anticariensis

We studied exopolysaccharides (EPSs) produced by Halomonas ventosae and Halomonas anticariensis, two novel species of halophilic bacteria. Under optimum environmental and nutritional conditions, H. ventosae strains Al12 T and Al16 excreted 28.35 mg and 28.95 mg of EPS per 100 ml of culture medium (34.55 and 38.6 mg of EPS per gram of dry cell weight) respectively. The molecular masses of the polymers were about 50 kDa and their main components were glucose, mannose and galactose. They had high protein fractions and showed emulsifying activity on several hydrophobic substrates. Under optimum environmental and nutritional conditions, H. anticariensis strains FP35 T and FP36 excreted about 29.65 and 49.95 mg of EPS per 100 ml of culture medium (43.6 and 50.95 mg of EPS per gram of dry cell weight) respectively. The molecular masses of the polymers were about 20 and 46 kDa respectively and were composed mainly of glucose, mannose and galacturonic acid. All EPSs produced solutions of low viscosity and pseudoplastic behaviour. They also had a high capacity for binding cations and incorporated considerable quantities of sulphates, which is highly unusual in bacterial polysaccharides. All strains assayed formed biofilms both in polystyrene wells and borosilicate test tubes.

Antioxidant properties and protein compositions of porcine haemoglobin hydrolysates

Porcine haemoglobin hydrolysates were prepared through hydrolysis by Alcalase followed by Flavourzyme, and their protein compositions were analyzed using Sephadex G-50 gel filtration chromatography. The antioxidant activities, including reducing power, ferrous ion chelating ability, and DPPH radical scavenging activity, of the hydrolysates were evaluated. The results showed that the hydrolysates of haemoglobin exhibited low reducing powers, but high ferrous ion chelating abilities and DPPH radical scavenging activities. The hydrolysate, obtained through hydrolysis by 2% Alcalase for 4 h and followed by 1% Flavourzyme for 6 h, had the highest ferrous ion chelating ability of 63.54% at a concentration of 5.0 mg/mL. The hydrolysate, obtained through hydrolysis by 2% Alcalase for 4 hrs, had the highest DPPH radical scavenging activity of 41.94% at a concentration of 5.0 mg/mL. According to the results of protein composition analysis, we divided the hydrolysates into three groups, including high molecular weight (MW) group (Group I), medium MW group (Group II), and low MW group (Group III). The reducing power and ferrous ion chelating ability of the hydrolysates were significantly and positively correlated to the relative amount of Group I, and negatively correlated to the relative amount of Group III. This study revealed that the antioxidant activities of porcine haemoglobin hydrolysates were dependent on their protein compositions. The high MW protein fraction (Group I) was responsible for the high reducing power and ferrous ion chelating ability of the hydrolysate.

Leishmania infantum released proteins specifically regulate cytokine expression and production patterns by CD4 + and CD8 + T cells

Specific immune responses by CD4 + and CD8 + T cells, from two infected mice strains (BALB/c and C57BL/6), induced by High, Inter and Low protein fractions released by Leishmania infantum, were assessed through the evaluation of IL-12, IFN-γ and IL-10 mRNA by real-time PCR and respective protein production by ELISA. During infection establishment, High and Inter fractions directed both mice strains T cells subsets to increase the production of IFN-γ, associated to IL-12 release. Later on, parasite replication augmented in BALB/c and stabilised in C57BL/6 mice. Inter fraction induced CD4 + T cells to maintain IFN-γ production, with the simultaneous release of IL-12 by both cell subsets in BALB/c mice and by CD8 + T cells in C57BL/6 mice. These observations suggested a prophylactic potential for Inter fraction which was able to induce Th1 response with IL-12 involvement, required for the maintenance of memory cells, in mice strains with different parasitic evolution.

Fine Grinding and Air Classification of Field Pea

ABSTRACTField pea has ≈23% protein, 48% starch, 8% sugars, 4% lipids, 7% crude fiber, and 3% ash. Pin milling at 1 × 14,000, 3 × 14,000, 9 × 14,000, and 12 × 14,000 rpm followed by air classification according to particle size resulted in fine fractions (&lt;18 μm) with high protein content and coarser fractions (&gt;18 μm) with high starch content. The yield of the high protein fraction increased with the intensity of grinding before air classification. The starch content of the high starch fraction increased with the intensity of grinding and subsequent air classification. Both whole pea and dehulled pea responded well to fine grinding and air classification, and the dehulled pea gave higher protein content and higher starch content than the corresponding fraction from whole pea. The protein fraction had high lysine content and met all the amino acid requirements of the World Health Organization for children older than two years and adults.

USE OF AN ASPIRATOR TO SEPARATE MEAT AND BONE MEAL INTO HIGH-ASH AND HIGH-PROTEIN STREAMS

Meat and bone meal (MBM) is a byproduct of the rendering industry. Novel feed and non-feed applications forthe protein and minerals in MBM are being developed. MBM would have improved characteristics for these applications ifthe bone and soft tissue-derived particles could be efficiently separated. An aspirator is a device that separates mixtures ofparticles based on the terminal velocity of each particle. The objective of this study was to evaluate whether an aspirator canbe used to separate MBM into high-ash and high-protein fractions. It was found that the cohesive MBM particles tended toclog the hopper and aspirator column and foul the other interior surfaces of the aspirator, making continuous operation ofthe aspirator problematic, unless a modification was made. The results show that with this modification, and appropriatesettings for feed rate and operating pressure, the aspirator produces two fractions, one that is considerably higher in ash,and one that is moderately higher in protein. Specifically, with an MBM feed rate of 8.0 g/s and an operating pressure of-116 Pa, the high-ash fraction was 52.0% ash (dry basis), compared to 34.5% ash in the unprocessed material. With a feedrate of 13.7 g/s and a pressure of -28 Pa, the high-protein fraction was 60.9% crude protein (dry basis), compared to 55.8%crude protein in the unprocessed material. The aspirator tested achieved a degree of separation that will facilitate the useof MBM in alternative applications.

Influence of a sugar moiety (rhamnosylglucoside) at 3- O position on the reactivity of quercetin with whey proteins

The reaction of whey proteins (WP) with quercetin and rutin (quercetin-3- O-rhamnosylglucoside) is influenced by the glycosidic bound sugar moiety. The protein derivatives formed showed a blocking of tryptophan (max. 49%), free amino (max. 32%) and thiol groups (max. 24%). The amount of quercetin and rutin bound covalently (up to 94 and 31 nmol mg −1, respectively) was estimated by their characteristic absorbance between 300 and 340 nm. At least one molecule of the phenolic reactant was covalently bound to a β-lactoglobulin molecule (β-Lg). High molecular protein fractions were detected by SDS-PAGE (cross-linking with quercetin). All results confirm that quercetin is more reactive than rutin. The pH-dependent solubility of the derivatives decreased, although their hydrophilic character increased. The structural changes (circular dichroism (CD)) showed that especially rutin causes perturbation of the secondary (decrease of α-helix elements accompanied by an increase in random coil) and tertiary structure. The in vitro proteolytic digestibility, especially of the rutin derivatives was elevated, due to an increase in denaturation of the derivatives.