Adding pulse flours to cereal-based snacks and bakery products: An overview of free asparagine quantification methods and mitigation strategies of acrylamide formation in foods.

Thermal processing techniques can lead to the formation of heat-induced toxic substances. Acrylamide is one contaminant that has received much scientific attention in recent years, and it is formed essentially during the Maillard reaction when foods rich in carbohydrates, particularly reducing sugars (glucose, fructose), and certain free amino acids, especially asparagine (ASN), are processed at high temperatures (>120°C). The highly variable free ASN concentration in raw materials makes it challenging for food businesses to keep acrylamide content below the European Commission benchmark levels, while avoiding flavor, color, and texture impacts on their products. Free ASN concentrations in crops are affected by environment, genotype, and soil fertilization, which can also influence protein content and amino acid composition. This review aims to provide an overview of free ASN and acrylamide quantification methods and mitigation strategies for acrylamide formation in foods, focusing on adding pulse flours to cereal-based snacks and bakery products. Overall, this review emphasizes the importance of these mitigation strategies in minimizing acrylamide formation in plant-based products and ensuring safer and healthier food options.

The Effect of Increasing Concentrations of Omega-3 Fatty Acids from either Flaxseed Oil or Preformed Docosahexaenoic Acid on Fatty Acid Composition, Plasma Oxylipin, and Immune Response of Laying Hens.

BACKGROUND: There is a lack of nutrition guidelines for the feeding of omega-3 polyunsaturated fatty acids (PUFA) to laying hens. Knowledge as to whether the type and concentrations of α-linolenic acid (ALA) and/or docosahexaenoic acid (DHA) in the diet can make a difference to the birds' immune responses when subjected to a lipopolysaccharide (LPS) challenge is limited. OBJECTIVES: The study was designed to determine the potential nutritional and health benefits to laying hens when receiving dietary omega-3 PUFA from either ALA or DHA. METHODS: A total of 80 Lohmann LSL-Classic (white egg layer, 20 wk old) were randomly assigned to 1 of 8 treatment diets (10 hens/treatment), provided 0.2%, 0.4%, 0.6%, or 0.8% of total dietary omega-3 PUFA, provided as either ALA-rich flaxseed oil or DHA-enriched algal biomass. After an 8-wk feeding period, the birds were challenged with Escherichia coli-derived LPS (8 mg/kg; i.v. injection), with terminal sample collection 4 h after challenge. Egg yolk, plasma, liver, and spleen samples were collected for subsequent analyses. RESULTS: Increasing dietary omega-3 supplementation yielded predictable responses in egg yolk, plasma, and liver fatty acid concentrations. Dietary intake of ALA contributed mainly to ALA-derived oxylipins. Meanwhile, eicosapentaenoic acid- and DHA-derived oxylipins were primarily influenced by DHA dietary intake. LPS increased the concentrations of almost all the omega-6 PUFA-, ALA-, and DHA-derived oxylipins in plasma and decreased hepatic mRNA expression of COX-2 and 5-LOX (P < 0.001) involved in the biosynthesis of oxylipins. LPS also increased mRNA expression of proinflammatory cytokine IFN-γ and receptor TLR-4 (P < 0.001) in the spleen. CONCLUSIONS: These results revealed that dietary intake of ALA and DHA had unique impacts on fatty acid deposition and their derived oxylipins and inflammatory responses under the administration of LPS in laying hens.

Combination of High Hydrostatic Pressure and Ultrafiltration to Generate a New Emulsifying Ingredient from Egg Yolk.

Egg yolk granule phosvitin (45 kDa) is a phosphoprotein known for its emulsifying properties. Recently, high hydrostatic pressure (HHP) treatment of granule induced the transfer of phosvitin to the soluble plasma fraction. This project evaluated the performance of the ultrafiltration (UF) used to concentrate phosvitin from the plasma fraction to produce a natural emulsifier. Phosvitin was characterized in plasma from a pressure-treated granule (1.73 ± 0.07% w/w) and in its UF retentate (26.00 ± 4.12% w/w). The emulsifying properties of both retentates were evaluated. The emulsion prepared with phosvitin-enriched retentate was more resistant to flocculation and creaming. Confocal laser scanning microscopy showed a network of aggregated protein similar to a gel, which encapsulated oil droplets in emulsions made with UF-retentate of plasma from pressure-treated granule. However, although sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that ß-phosvitin is recovered in the cream, it is difficult to attribute the improved emulsifying properties of the UF-retentate of plasma from pressure-treated granules only to phosvitin.

Effect of Fermentation on the Protein Digestibility and Levels of Non-Nutritive Compounds of Pea Protein Concentrate.

In order to determine the impact of fermentation on protein quality, pea protein concentrate (PPC) was fermented with Lactobacillus plantarum for 11 h and total phenol and tannin contents, protease inhibitor activity, amino acid composition and in vitro protein digestibility were analyzed. Phenol levels, expressed as catechin equivalents (CE), increased on dry mass basis from 2.5 at 0 h to 4.9 mg CE per 1 g of PPC at 11 h. Tannin content rose from 0.14 at 0 h to a maximum of 0.96 mg CE per 1 g of PPC after 5 h, and thereafter declined to 0.79 mg/g after 11 h. After 9 h of fermentation trypsin inhibitor activity decreased, however, at all other fermentation times similar levels to the PPC at time 0 h were produced. Chymotrypsin inhibitor activity decreased from 3.7 to 1.1 chymotrypsin inhibitory units (CIU) per mg following 11 h of fermentation. Protein digestibility reached a maximum (87.4%) after 5 h of fermentation, however, the sulfur amino acid score was reduced from 0.84 at 0 h to 0.66 at 11 h. This reduction in sulfur content altered the in vitro protein digestibility-corrected amino acid score from 67.0% at 0 h to 54.6% at 11 h. These data suggest that while fermentation is a viable method of reducing certain non-nutritive compounds in pea protein concentrate, selection of an alternative bacterium which metabolises sulfur amino acids to a lesser extent than L. plantarum should be considered.

Effects of High Hydrostatic Pressure Processing on Hen Egg Compounds and Egg Products.

High hydrostatic pressure (HHP), used alone or with other processes, is an emerging technology increasingly used in the food industry to improve microbial safety, and the functionality and bioactive properties of food products. HHP provides a way to reduce energy requirements for food processing and may contribute to improved energy efficiency in the food industry. Hen egg is used by the food industry to formulate many food products. To improve the microbiological safety of egg and egg-derived products, HHP processing is an attractive alternative to heat- pasteurization and a potential technology. However, HHP treatment induces structural modifications of egg components (such as proteins) which could positively or negatively affect the physicochemical and functional properties of egg-derived products. Improving our knowledge regarding the potential of HHP in the egg industry will add value to the final food products and increase profitability for egg producers and the food industry.

A Vitamin B-6 Antagonist from Flaxseed Perturbs Amino Acid Metabolism in Moderately Vitamin B-6-Deficient Male Rats.

BACKGROUND: Pyridoxal 5'-phosphate (PLP) plays a crucial role as a cofactor in amino acid metabolism. There is a prevalence of moderate vitamin B-6 deficiency in the population that may be exacerbated through the ingestion of 1-amino d-proline (1ADP), a vitamin B-6 antagonist found in flaxseed. OBJECTIVE: Given prior evidence of the impact of synthetic 1ADP on indexes of pyridoxine metabolism, the current study was designed to investigate the effects of 1ADP derived from flaxseed on amino acid metabolism in moderately vitamin B-6-deficient rats. METHODS: Male weanling rats (n = 8/treatment) consumed a semipurified diet containing either 7 mg pyridoxine hydrochloride/kg diet [optimum vitamin B-6 (OB)] or 0.7 mg pyridoxine hydrochloride/kg diet [moderately vitamin B-6 deficient (MB)], each with 0 or 10 mg vitamin B-6 antagonist/kg diet, in either a synthetic form (1ADP) or as a flaxseed extract (FE), for 5 wk. At the end of the experiment, plasma vitamin B-6 and amino acid concentrations and the activities of hepatic PLP-dependent enzymes were analyzed. RESULTS: Compared with the MB control group, plasma PLP concentrations were 26% and 69% lower, respectively, in the MB+FE and MB+1ADP rats (P ≤ 0.001). In the MB+FE group, the plasma cystathionine concentration was 100% greater and the plasma α-aminobutyric acid and glutamic acid concentrations were 59% and 30% lower, respectively, than in the MB control group. Both synthetic 1ADP and FE significantly (P < 0.001) inhibited the in vitro hepatic activities of 2 PLP-dependent enzymes, cystathionine ß-synthase (up to 44%) and cystathionine γ-lyase (up to 60%), irrespective of vitamin B-6 concentrations. Because of vitamin B-6 antagonist exposure, observed perturbations in plasma biomarkers and hepatic enzyme activities were not evident or of lesser magnitude in rats consuming adequate vitamin B-6. CONCLUSION: The current data from a rat model provide evidence that a vitamin B-6 antagonist now prevalent in the human food supply may pose challenges to individuals of moderate vitamin B-6 status.

Investigation of vitamin B6 inadequacy, induced by exposure to the anti-B6 factor 1-amino D-proline, on plasma lipophilic metabolites of rats: a metabolomics approach.

PURPOSE: Vitamin B6 status in the body is affected by several factors including dietary supply of the antivitamin B6 factor, 1-amino D-proline (1ADP), which is present in flaxseed. Owing to the prevalence of moderate B6 deficiency in the general population, a co-occurrence of 1ADP may lead to a further deterioration of B6 status. To this end, we applied a nontargeted metabolomics approach to identify potential plasma lipophilic biomarkers of deleterious effect of 1ADP on moderately vitamin B6-deficient rats using a high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. METHODS: Twenty-four rats were fed with a semi-purified diet containing pyridoxine·HCl (PN·HCl) either 7 mg/kg diet (optimal B6) or 0.7 mg/kg diet (moderate B6). The rats were divided into four treatments (n = 6), and one treatment in each B6 diet group was also fed ad libitum with 10 mg/kg diet of synthetic 1ADP. After 5 weeks of study, plasma was collected from the rats and lipophilic metabolites were extracted using acetonitrile as a solvent for analysis. RESULTS: Ten potential plasma lipophilic biomarkers were identified out of >2500 detected entities, which showed significant differences between the treatments. Plasma glycocholic acid, glycoursodeoxycholic acid, murocholic acid, N-docosahexaenoyl GABA, N-arachidonoyl GABA, lumula, nandrolone and orthothymotinic acid concentrations were significantly elevated, while plasma cystamine and 3-methyleneoxindole concentrations were significantly reduced as a result of either low B6 status or 1ADP or their interaction. CONCLUSION: Changes in these metabolites revealed a potential defect in pathways linked with the biosynthesis and metabolism of bile acid components, N-acyl amino acids, analgesic androgens, anti-inflammatory and neuroprotective molecules. We also noted that the changes in these biomarkers can be alleviated by the application of adequate vitamin B6.

Folic acid supplementation during high-fat diet feeding restores AMPK activation via an AMP-LKB1-dependent mechanism.

AMPK is an endogenous energy sensor that regulates lipid and carbohydrate metabolism. Nonalcoholic fatty liver disease (NAFLD) is regarded as a hepatic manifestation of metabolic syndrome with impaired lipid and glucose metabolism and increased oxidative stress. Our recent study showed that folic acid supplementation attenuated hepatic oxidative stress and lipid accumulation in high-fat diet-fed mice. The aim of the present study was to investigate the effect of folic acid on hepatic AMPK during high-fat diet feeding and the mechanisms involved. Male C57BL/6J mice were fed a control diet (10% kcal fat), a high-fat diet (60% kcal fat), or a high-fat diet supplemented with folic acid (26 mg/kg diet) for 5 wk. Mice fed a high-fat diet exhibited hyperglycemia, hepatic cholesterol accumulation, and reduced hepatic AMPK phosphorylation. Folic acid supplementation restored AMPK phosphorylation (activation) and reduced blood glucose and hepatic cholesterol levels. Activation of AMPK by folic acid was mediated through an elevation of its allosteric activator AMP and activation of its upstream kinase, namely, liver kinase B1 (LKB1) in the liver. Consistent with in vivo findings, 5-methyltetrahydrofolate (bioactive form of folate) restored phosphorylation (activation) of both AMPK and LKB1 in palmitic acid-treated HepG2 cells. Activation of AMPK by folic acid might be responsible for AMPK-dependent phosphorylation of HMG-CoA reductase, leading to reduced hepatic cholesterol synthesis during high-fat diet feeding. These results suggest that folic acid supplementation may improve cholesterol and glucose metabolism by restoration of AMPK activation in the liver.

Identification and Characterization of a Pepsin- and Chymotrypsin-Resistant Peptide in the α Subunit of the 11S Globulin Legumin from Common Bean (Phaseolus vulgaris L.).

The 11S globulin legumin typically accounts for approximately 3% of the total protein in common beans (Phaseolus vulgaris). It was previously reported that a legumin peptide of approximately 20 kDa is resistant to pepsin digestion. Sequence prediction suggested that the pepsin-resistant peptide is located at the C-terminal end of the α-subunit, within a glutamic acid-rich domain, overlapping with a chymotrypsin-resistant peptide. Using purified legumin, the peptide of approximately 20 kDa was found to be resistant to pepsin digestion in a pH-dependent manner, and its location was determined by two-dimensional gel electrophoresis and LC-MS-MS. The location of the chymotrypsin-resistant peptide was confirmed by immunoblotting with peptide-specific polyclonal antibodies. The presence of a consensus site for proline hydroxylation and arabinosylation, the detection of hydroxyproline residues, purification by lectin affinity chromatography, and a difference in electrophoretic migration between the chymotrypsin- and pepsin-resistant peptides suggest the presence of a large O-glycan within these peptides.

Splenic gene expression of cytokines at multiple time points following lipopolysaccharide challenge in layers.

OBJECTIVE: To investigate inflammatory responses to lipopolysaccharide (LPS) injection in layers. ANIMALS: 33 40-week-old laying hens were used. METHODS: 30 laying hens were divided into 2 groups: the first group was injected with 8 mg/kg LPS, while the second group was injected with sterile saline. At the start of the study, 3 birds served as a baseline and were used as the time 0 controls for both the saline and LPS-treated groups. Blood and spleen tissues were collected at 0 (before) and 1, 2, 3, 4, and 6 hours after injection. RESULTS: LPS administration increased splenic mRNA levels of IL-1ß, IL-2, IL-6, IL-8, IL-10, interferon-γ, and tumor necrosis factor-α (P < .001) and serum IL-6 levels (P < .01) compared to saline injection. The mRNA expression of most cytokine genes increased rapidly toward peak values within 2 hours after the LPS injection, and then the difference between the saline and LPS treatments got smaller as time went on; serum IL-6 reached its highest concentration 2 hours after LPS administration. The magnitude of LPS-induced upregulation of gene expression was the highest for IL-6, followed by IL-1ß and IL-8, and tumor necrosis factor-α was the least affected. CLINICAL RELEVANCE: The temporal and quantitative profile of these inflammatory mediators generated from this study provides valuable information in identifying the optimal time window and appropriate biomarkers for LPS-induced inflammation, which has significant implications in evaluating the effects of interventions on the immune system of chickens.

Options for substantiating protein content claims for conventional foods.

In Canada and the United States, front-of-package protein content claims require data to support the quality of the protein. In general, protein quality reflects the product of the amino acid composition of the food protein relative to human amino acid requirements and a measure of digestibility. The currently accepted method in both jurisdictions is the protein digestibility-corrected amino acid score (PDCAAS) that requires the measurement of true fecal protein (nitrogen) digestibility. The latter must be measured in vivo using a rat model. This requirement for animal testing is inconsistent with international efforts to reduce the usage of animals in testing for regulatory purposes. The current commentary positions four options to remove the need to use animal testing for determining protein quality, when considering protein content claim substantiation. These options include (i) a focus on protein quantity alone; (ii) the use of the amino acid score alone, with no correction for digestibility; (iii) the use of a fixed digestibility coefficient to estimate protein quality; and (iv) the use of in vitro methods to measure protein and/or amino acid digestibility. The relative merits and deficiencies of the options are positioned with the goal of encouraging dialogue within the regulatory agencies to move towards alternative approaches for substantiating protein content claims on foods, including those derived from plant-based sources.

Effects of Feed Moisture Content on the Physical and Nutritional Quality Attributes of Sunflower Meal-based High-Moisture Meat Analogues.

Adding value to food industry by-products, like sunflower meal (SFM), through their utilization as ingredients in new food products can improve sustainability of food systems. This research investigated extrusion cooking to produce high-moisture meat analogues (HMMAs) made from blends of soy protein isolate and expeller-pressed SFM. The effects of feed moisture content [FMC] (60, 65, and 70%, wet basis) and SFM concentration (37.5, 50, and 62.5%, total blend weight basis) on physical and protein nutritional quality attributes of HMMAs were investigated. The processing temperatures (including cooling die), screw speed and feed rate were kept constant at 60-80-115-125-50-25 °C (from feeder to the die end), 200 rpm and 0.5 kg/h (dry basis), respectively. An increase in SFM concentration and FMC significantly (p < 0.05) reduced the mechanical energy requirements for extrusion. Cutting strength and texture profile analysis of HMMAs indicated softer texture with increases in SFM and FMC. X-ray microcomputed tomography analysis revealed that the microstructure of the HMMAs at the centre and towards the surface was different and affected by SFM concentration and FMC. The in vitro-protein digestibility corrected amino acid score of the HMMAs ranged between 85 and 91% and did not show significant (p < 0.05) changes as a function of FMC or SFM concentration. HMMAs produced from 37.5% SFM at 70% FMC showed no deficiency in essential amino acids for all age categories except for infants, suggesting the high potential of SFM and soy protein blends for creating nutritious meat alternative products. Overall, this work provided valuable insights regarding the effects of soy protein replacement by SFM on the textural, microstructural and nutritional quality of HMMA applications, paving the way for value-addition to this underutilized food industry by-product.

In vitro protein digestibility to replace in vivo digestibility for purposes of nutrient content claim substantiation in North America's context.

The reliance by North American regulatory authorities on in vivo rodent bioassays-Protein Correct-Amino Acid Score (PDCAAS) in the U.S. and Protein Efficiency Ratio (PER) in Canada-to measure the protein quality for protein content claim substantiation represents a major barrier for innovation in the development and marketing of protein foods. Although FAO in 2013 proposed a new method (Digestible Indispensable Amino Acid Score, DIAAS), it is still not used for protein content claim substantiation in any jurisdiction. Together with public health efforts to increase the consumption of plant-based foods, removing hurdles is key to incentivizing the food industry to measure protein digestibility in making food formulation decisions as well as in claiming protein content on product labels. To address this issue, a pathway has been proposed to position alternative methods for in vitro protein digestibility in collaborative studies to generate the data necessary for method approval by a certifying body. The latter is critical to the potential recognition of these methods by both Health Canada and the US FDA. The purpose of this article is to briefly summarize the state-of-the-art in the field, to inform the research community of next steps, and to describe the path engaging collaborative laboratories in a proficiency test as the first step in moving forward toward acceptance of in vitro digestibility methods. Throughout, a consultative and iterative process will be utilized to ensure the program goals are met. Success will be achieved when the proposed path results in the acceptance of an in vitro methods for protein digestibility used for PDCAAS determinations, which will enable increased protein analyses and improved nutrition labeling of protein foods.

The in vivo and in vitro protein quality of three hemp protein sources.

In this work, the protein quality of defatted hemp hearts and protein-enriched hemp fractions was determined. Protein quality was assessed using a rodent bioassay to evaluate growth and protein digestibility, while amino acid composition was determined via HPLC. A method for determining in vitro protein digestibility was compared to in vivo methodology and used to generate an in vitro protein quality score. The true protein digestibility of hemp protein 2, a hemp protein concentrate, was significantly lower than that of either defatted hemp hearts or hemp protein 1, a hemp protein concentrate (p < .05). While there was no relationship between the in vivo and in vitro measurements of protein digestibility (R 2 = .293, p = .459), there was a significant correlation between the protein digestibility-corrected amino acid score (PDCAAS) determined in vivo and in vitro PDCAAS (R 2 = .989, p = .005). The protein efficiency ratio of hemp protein 1 was significantly lower than that of either defatted hemp hearts or hemp protein 2 (p < .05). These data highlight the nutritional capacity of hemp protein sources while also demonstrating the relationship between in vivo and in vitro methods for determining protein quality.

Plant Proteins: Methods of Quality Assessment and the Human Health Benefits of Pulses.

As countries increase their standard of living and individual income levels rise, there is a concomitant increase in the demand for animal-based protein. However, there are alternative sources. One of the alternatives available is that of increased direct human consumption of plant proteins. The quality of a dietary protein is an important consideration when discussing the merits of one protein source over another. The three most commonly used methods to express protein quality are the protein efficiency ratio (PER), a weight gain measurement; protein digestibility-corrected amino acid score (PDCAAS); and the digestible indispensable amino acid score (DIAAS). The possibility that alterations in the quality and quantity of protein in the diet could generate specific health outcomes is one being actively researched. Plant-based proteins may have additional beneficial properties for human health when compared to animal protein sources, including reductions in risk factors for cardiovascular disease and contributions to increased satiety. In this paper, the methods for the determination of protein quality and the potential beneficial qualities of plant proteins to human health will be described.

Effects of genotype, environment and their interaction on protein and amino acid contents in soybeans.

Soybean [Glycine max (L.) Merr.] is an important source of protein and oil. Genotype, environment and the interaction of genotype × environment influence the protein composition in soybean seeds. The main objectives of this study were to i) study the influence of genotype, environment and their interaction on soybean protein and amino acid contents; ii) evaluate the stability of soybean genotype across various environments, with a focus on soybeans grown in a northern latitude; and iii) identify the correlation between crude protein and critical amino acid value (CAAV). Twenty-three soybean genotypes were grown at four locations in Manitoba, Canada for two years (2018 and 2019). Soybean seeds were analyzed for protein and amino acids (nine essential amino acids and cysteine). The effects of genotype, environment and genotype × environment interaction on all traits were significant (P < 0.05). Genotype and environments explained the main part of variation for all traits. G13 and G15 cultivars performed better in favorable environments (bi > 1), and G22 cultivar showed greater resistance to environmental change. Protein and amino acids responded differently to various environments, but the optimal environments for greater soybean protein and amino acid remains to be established. The CAAV had a negative linear relationship with protein content in soybean (k = -0.17). This work expands our knowledge of the factors impacting the protein quality of soybeans grown in northern latitudes.

Impact of cooking on the protein quality of Russet potatoes.

Despite being low in crude protein, on a fresh weight basis, given their overall contribution to the North American diet, potatoes contribute approximately 2%-4% of the population's protein intake. However, the quality of the protein remains ill-defined. To that end, Russet potatoes were secured and subjected to various cooking conditions (raw [control], boiled, baked, microwaved, and fried [3, 6, and 9 min]) to determine the impact of cooking method on protein quality, as determined by amino acid score (AAS) and indices of in vivo true fecal protein digestibility (TFPD%; rodent bioassay) and in vitro protein digestibility (pH-drop, pH-Stat, and simulated gastrointestinal digestion both static and dynamic). The AAS of raw Russet potatoes was 0.67 ± 0.01, with histidine being the limiting AA. Frying led to a significant reduction in the AAS, however, other cooking methods yielded similar results to the raw control. The TFPD% of raw potato was low (40.5% ± 3.9%) and was significantly enhanced to over 80% with all cooking methods. Similar patterns were observed with all in vitro measures, however, all methods yielded higher values for the raw control samples. Final protein digestibility-corrected AAS (PDCAAS; product of AAS and TFPD%) values ranged from 0.27 (raw) to a high of 0.57 (boiled), with cooked values being comparable to other plant-based protein sources, including grains, and some nuts and pulses. In vitro PDCAAS values followed similar trends. This study defined the protein quality of cooked Russet potatoes and provides data for use in defining the quality of total protein consumed in the North American diet.

Quantitative trait loci associated with amino acid concentration and in vitro protein digestibility in pea (Pisum sativum L.).

With the expanding interest in plant-based proteins in the food industry, increasing emphasis is being placed on breeding for protein concentration and quality. Two protein quality traits i.e., amino acid profile and protein digestibility, were assessed in replicated, multi-location field trials from 2019 to 2021 in pea recombinant inbred line population PR-25. This RIL population was targeted specifically for the research of protein related traits and its parents, CDC Amarillo and CDC Limerick, had distinct variations in the concentration of several amino acids. Amino acid profile was determined using near infrared reflectance analysis, and protein digestibility was through an in vitro method. Several essential amino acids were selected for QTL analysis, including lysine, one of the most abundant essential amino acids in pea, and methionine, cysteine, and tryptophan, the limiting amino acids in pea. Based on phenotypic data of amino acid profiles and in vitro protein digestibility of PR-25 harvested in seven location-years, three QTLs were associated with methionine + cysteine concentration, among which, one was located on chromosome 2 (R2 = 17%, indicates this QTL explained 17% phenotypic variation of methionine + cysteine concentration within PR-25), and two were located on chromosome 5 (R2 = 11% and 16%). Four QTLs were associated with tryptophan concentration and are located on chromosome 1 (R2 = 9%), chromosome 3 (R2 = 9%), and chromosome 5 (R2 = 8% and 13%). Three QTLs were associated with lysine concentration, among which, one was located on chromosome 3 (R2 = 10%), the other two were located on chromosome 4 (R2 = 15% and 21%). Two QTLs were associated with in vitro protein digestibility, one each located on chromosomes 1 (R2 = 11%) and 2 (R2 = 10%). QTLs associated with in vitro protein digestibility, and methionine + cysteine concentration on chromosome 2 were identified to be co-localized with known QTL for total seed protein concentration in PR-25. QTLs associated with tryptophan and methionine + cysteine concentration co-localized on chromosome 5. The identification of QTLs associated with pea seed quality is an important step towards marker-assisted selection of breeding lines with improved nutritional quality, which will further boost the competitiveness of pea in plant-based protein markets.

Impact of Ultra-High Pressure Homogenization on the Structural Properties of Egg Yolk Granule.

Ultra-high pressure homogenization (UHPH) is a promising method for destabilizing and potentially improving the techno-functionality of the egg yolk granule. This study's objectives were to determine the impact of pressure level (50, 175 and 300 MPa) and number of passes (1 and 4) on the physico-chemical and structural properties of egg yolk granule and its subsequent fractions. UHPH induced restructuration of the granule through the formation of a large protein network, without impacting the proximate composition and protein profile in a single pass of up to 300 MPa. In addition, UHPH reduced the particle size distribution up to 175 MPa, to eventually form larger particles through enhanced protein-protein interactions at 300 MPa. Phosvitin, apovitellenin and apolipoprotein-B were specifically involved in these interactions. Overall, egg yolk granule remains highly stable during UHPH treatment. However, more investigations are needed to characterize the resulting protein network and to evaluate the techno-functional properties of UHPH-treated granule.

Alteration of the dietary methionine: Cysteine ratio modulates the inflammatory response to an inter-peritoneal injection of lipopolysaccharide in wistar rats.

Sulphur amino acids (SAA) are essential for multiple physiological/metabolic processes, with the ratio of dietary methionine: cysteine (Met:Cys) being an important contributor to pro-inflammatory responses, including TNF-α activity. The current study was designed to determine the effect an altered dietary SAA ratio, and the resulting reliance on the transsulfuration pathway to supply Cys, will have on the inflammatory response. In the present study, 100 µg/kg of an intraperitoneal (IP) injection of lipopolysaccharide (LPS) was used as a model for systemic inflammation. Male Wistar rats were randomized to one of two amino acid-defined diets, (100Met:0Cys or 50Met:50Cys) and subdivided to receive either IP LPS or saline injections. LPS significantly increased total plasma Cys, homocysteine (Hcy) and glutathione (GSH) 240 min post-IP injection in rats fed a 50Met:50Cys ratio compared to other treatments. The TNF-α area under the curve for LPS-treated rats consuming a dietary 50Met:50Cys ratio was significantly higher (P < .004) compared to those consuming a dietary 100Met:0Cys ratio. A significant increase in the percentage of leukocytes that were neutrophils was observed in rats injected with LPS when compared to saline with no effect of diet. These results demonstrate that an alteration of the dietary Met:Cys ratio did not attenuate the inflammatory response to an IP injection of LPS in Wistar rats; however, a diet with a balanced Met:Cys ratio increased concentrations of Cys and GSH which may result in a more rapid response to an LPS challenge.