Protein Extracts Research Articles

Decoding the Duality of Antinutrients: Assessing the Impact of Protein Extraction Methods on Plant-Based Protein Sources.

This review aims to provide an updated overview of the effects of protein extraction/recovery on antinutritional factors (ANFs) in plant protein ingredients, such as protein-rich fractions, protein concentrates, and isolates. ANFs mainly include lectins, trypsin inhibitors, phytic acid, phenolic compounds, oxalates, saponins, tannins, and cyanogenic glycosides. The current technologies used to recover proteins (e.g., wet extraction, dry fractionation) and novel technologies (e.g., membrane processing) are included in this review. The mechanisms involved during protein extraction/recovery that may enhance or decrease the ANF content in plant protein ingredients are discussed. However, studies on the effects of protein extraction/recovery on specific ANFs are still scarce, especially for novel technologies such as ultrasound- and microwave-assisted extraction and membrane processing. Although the negative effects of ANFs on protein digestibility and the overall absorption of plant proteins and other nutrients are a health concern, it is also important to highlight the potential positive effects of ANFs. This is particularly relevant given the rise of novel protein ingredients in the market and the potential presence or absence of these factors and their effects on consumers' health.

Effect of Lentinus sajor-caju on the chemical composition and antioxidant activity of highland barley straw under solid-state fermentation.

The efficient utilization of straw resources as animal feed has gained considerable attention. The objective of this study was to evaluate whether Lentinus sajor-caju treatment alters the chemical composition and antioxidant activity of highland barley straw and enhances its functional value as a ruminant feed. The chemical composition, antioxidant capacity, and metabolomic profile of highland barley straw were determined after 21 days of solid-state fermentation with L. sajor-caju at 25°C. The differential metabolites between fermented and unfermented highland barley straw were identified by LC-MS and the relationship between the identified metabolites and antioxidant capacity was elucidated. The results showed that, compared with untreated highland barley straw, the crude protein and ether extract contents were higher (51.55 and 76.43%, respectively) in highland barley straw after 21 days of incubation with L. sajor-caju, whereas the hemicellulose, cellulose, and acid detergent lignin contents were lower (2.48, 25.08, and 45%, respectively). The total antioxidant capacity was significantly higher in L. sajor-caju-treated than in untreated highland barley straw. In total, 600 differential metabolites (301 upregulated and 299 downregulated) were identified between L. sajor-caju-fermented and unfermented highland barley straw. Correlation analysis results showed that Fe2+ scavenging and total phenolic content were strongly correlated with total antioxidant capacity. Meanwhile, the differential flavonoid metabolites between fermented and unfermented highland barley straw were primarily associated with antioxidant activity, with kaempferol 3-xylosylglucoside, isoginkgetin, and rhoifolin being the most representative. Thus, this study demonstrates that L. sajor-caju could enhance the functional value of highland barley straw, showing the potential of L. sajor-caju for improving the utilization of agricultural straws in ruminants.

Changes of the Physicochemical Properties and Structural Characteristics of Alkali-Extracted Polysaccharides from Agrocybe cylindracea Across the Growth Process.

Polysaccharides derived from Agrocybe cylindracea have been demonstrated to exhibit various bioactivities. However, studies on their structural characteristics during the growth process are limited. This study aimed to compare the physicochemical properties and structural characteristics of alkali-extracted polysaccharides from A. cylindracea fruiting bodies (JACP) across four growth stages. Results showed that the extraction yields and protein levels of JACP declined along with the growth of A. cylindracea, while the contents of neutral sugar and glucose increased significantly. However, JACP exhibited structural characteristics similar to those across the four stages. Four polysaccharide subfractions were isolated from each growth stage, including JACP-Et30, JACP-Et50, JACP-Et60, and JACP-Et70. JACP-Et30 from the four stages and JACP-Et50 from the initial three stages were identified as heteroglucans with β-1,3-d-Glcp and β-1,6-d-Glcp residues as main chains, respectively. However, other subfractions were considered as β-1,6-d-glucans containing minor glucuronic acid. These subfractions were predominantly replaced by Glcp residues at the O-3 and O-6 positions. Overall, while JACP exhibited variable physicochemical properties, its structural characteristics remained stable during the growth process, offering new insights into its potential applications in the food and medicinal industries.

Extraction, structural and functional properties of lipophilic protein isolated from peanut defatted powder

Peanut isolated protein (PIP), peanut arachin (ARA), and peanut lipophilic protein (PLP) were obtained from peanut defatted powder (PDP) by the isoelectric point precipitation method. and their chemical, structural, and functional properties were evaluated. Chloroform-methanol method disclosed that PLP contained largest amount of lipids (10.98 ± 0.34%). Fourier transform infrared spectroscopy and X-ray diffraction detected that the four proteins had similar spectrum charateristics. However, PLP displayed the highest contents of α-helix and β-sheet indicating a more compact tertiary structure accompanied by significantly highest solubility, emulsifiability, and emulsion stability compared to other three protein components (P < 0.05). Both the water holding capacity and fat holding capacity of PLP were higher, but its gel forming capacity and gel stability were lower compared to ARA. Composition analysis demonstrated that PLP had similar amino acid pattern to that of PIP, and each 100g of PLP contained 7.24g unsaturated fatty acid which composed of 17 fatty acids. These results suggested that PLP was a lipid-rich protein in peanut which could be a potential functional ingredient in the food industry.

Modified xanthan gum (natural polymeric material) and its derivative for wastewater treatment: A review

AbstractNaturally occurring xanthan gum (XG) has much commercial importance because of its excellent physicochemical, eco‐friendly, and non‐toxic properties. It is used in various applications like protein extraction, wastewater treatment, tissue engineering, drug delivery, food packaging, and so forth. XG is a natural material, and it has some limitations related to the mechanical stress, thermal stability, and hydration. To overcome the limitation, XG can be modified by adding third component or modification of operation for specific applications. XG can be modified by physical, genetically, enzymatically, or chemical processes. Revamped XG also enhances the efficiency toward adsorbing toxic metal ions and organics from synthetic or industrial effluents. The emphasis of present review article is to address the structural characteristics along with the focus on the developing chemically modified XG like grafted, cross‐linked, nanocomposites, and functionally modified biopolymer. However, this review commences thorough discussion on numerous ways of modifications, which can be attempted in XG structure, expanding its applications for heavy metal ion along with dye removal.

Anaerobically mineralized nitrogen as a potential indicator of the activity and abundance of mycorrhizal fungi in Mollisols

Anaerobically mineralized nitrogen (AN) is a suitable soil health indicator. The AN is sensitive to soil use changes and is related to soil and particulate organic carbon and aggregate stability. This work aims to evaluate the relationship between AN and 1) easily extractable glomalin-related soil proteins; 2) abundance of arbuscular mycorrhizal fungi measured by the number of arbuscular mycorrhizal fungi spores, and 3) arbuscular mycorrhizal fungi activity (root colonization). Soil samples were taken at depths of 0-5 and 5-20 cm from cultivated and uncultivated plots throughout the southeastern province of Buenos Aires. Anaerobically mineralized nitrogen, soil organic carbon, particulate organic carbon, aggregate stability, easily extracted glomalin-related soil proteins and the logarithm of the number of arbuscular mycorrhizal fungi spores (log spores) at 0-5, 5-20 and 0-20 cm depths were determined. In wheat roots, the percentages of total infection and arbuscules at 0-20 cm were measured. At all depths, AN was positively correlated to easily extractable glomalin-related soil proteins (r=0.34-0.65), which is an indicator of arbuscular mycorrhizal fungi activity and abundance. Likewise, AN was positively related to log-spores (r=0.58-0.78), which is an indicator of arbuscular mycorrhizal fungi abundance. However, AN was not related to root colonization (the percentages of total infection and arbuscules) that manifests the activity of arbuscular mycorrhizal fungi at a specific moment. Thus, anaerobically mineralized nitrogen would be an indicator of mid- to long-term changes in arbuscular mycorrhizal fungi abundance and activity (easily extractable glomalin-related soil proteins and log-spores) resulting from soil use. Consequently, the AN would allow monitoring an important aspect of soil microbiological health associated with arbuscular mycorrhizal fungi. However, it is necessary to evaluate the relationships studied in this work in a wider range of soil situations.

Relating the protein denaturation degree and solubility of soy protein isolates to the structure of high moisture extrudates

Commercial soy protein isolates (SPI) with high protein denaturation degrees and low solubilities are often used raw materials for the production of meat analogues with high moisture extrusion (HME). The impact of such SPI properties on structure formation and protein-protein interactions/reactions that occur during HME processing is not well-understood. Therefore, SPI with (i) native and soluble proteins, (ii) denatured and aggregated proteins or (iii) blends thereof were subjected to lab-scale HME processing. Most native and soluble SPI proteins took part in the formation of new non-covalent interactions and disulfide bonds during HME processing, which resulted in a layered extrudate microstructure. In addition, even after disruption of non-covalent and covalent bonds, high MW aggregates (>100 kDa) were present in the extrudate. SPI with highly aggregated protein had low protein extractability and HME did not cause a pronounced further reduction in this regard. HME did, however, result in the formation of a fibrous extrudate structure. Extrusion of blends with intermediate content of both SPIs resulted in the highest extrudate hardness and cutting strength. These findings demonstrate a significant impact of SPI protein denaturation degree and solubility on high moisture extrudate structure and texture. Hence, in-depth evaluation of the protein physical properties of raw materials used for HME processing will aid in controlling product properties.

Investigating the Nutritional and Functional Properties of Protaetia brevitarsis Larvae and Isolated Soy Protein Mixtures as Alternative Protein Sources.

The growing demand for sustainable and alternative protein sources has spurred interest in insect-based and plant-based proteins. Protaetia brevitarsis (PB) larvae and isolated soy protein (ISP) are notable in this regard, offering potential health benefits and nutritional enhancements. We assessed the feasibility of PB larvae and ISP mixtures as alternative food ingredients. Methods included the optimized purification and freeze-drying of PB larvae, extraction and refinement of legume proteins, physicochemical and antioxidant capacity evaluations, DPPH radical scavenging activity measurement, total phenolic and flavonoids content quantification, general component analysis, amino acid profiling using HPLC, fatty acid profiling through gas chromatography, and mineral content analysis using inductively coupled plasma spectrometry. The study found that certain PB:ISP ratios, particularly a 7:3 ratio, significantly improved the blend's antioxidant capacity, as evidenced by DPPH scavenging activity. This ratio also impacted the nutritional profile by altering the mixture's general components, with a notable increase in moisture, crude protein, and fiber and a decrease in crude fat and ash. Amino acid analysis revealed a balanced presence of essential and non-essential amino acids. The fatty acid profile was rich in unsaturated fatty acids, especially in certain ratios. Mineral analysis showed a complex interplay between PB larvae and ISP, with some minerals decreasing and others increasing in the blend. PB larvae and ISP mixtures have significant potential as alternative protein sources, offering a diversified nutritional profile and enhanced antioxidant properties. The 7:3 ratio of PB larvae to ISP has been shown to be particularly effective, suggesting that this ratio may offer an optimal balance for enhancing the overall nutritional quality of the mixture. This study sets the stage for future research to further explore and optimize the potential of these mixtures for human consumption while considering the challenges of consumer acceptance and long-term safety.

Determination of vancomycin and meropenem in serum and synovial fluid of patients with prosthetic joint infections using UPLC-MS/MS.

Numerous studies have suggested that intra-articular administration of antibiotics following primary revision surgery may be one of the methods for treating prosthetic joint infection (PJI). Vancomycin and meropenem are the two most commonly used antibiotics for local application. Determining the concentrations of vancomycin and meropenem in the serum and synovial fluid of patients with PJI plays a significant role in further optimizing local medication schemes and effectively eradicating biofilm infections. This study aimed to establish a rapid, sensitive, and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determining the concentrations of vancomycin and meropenem in human serum and synovial fluid. Serum samples were processed using acetonitrile precipitation of proteins and dichloromethane extraction, while synovial fluid samples were diluted before analysis. Chromatographic separation was achieved in 6min on a Waters Acquity UPLC BEH C18 column, with the mobile phase consisting of 0.1% formic acid in water (solvent A) and acetonitrile (solvent B). Quantification was carried out using a Waters XEVO TQD triple quadrupole mass spectrometer with an electrospray ionization (ESI) source in positive ion mode. The multiple reaction monitoring (MRM) mode was employed to detect the following quantifier ion transitions: 717.95-99.97 (norvancomycin), 725.90-100.04 (vancomycin), 384.16-67.99 (meropenem). The method validation conformed to the guidelines of the FDA and the Chinese Pharmacopoeia. The method demonstrated good linearity within the range of 0.5-50 μg/ml for serum and 0.5-100 μg/ml for synovial fluid. Selectivity, intra-day and inter-day precision and accuracy, extraction recovery, matrix effect, and stability validation results all met the required standards. This method has been successfully applied in the pharmacokinetic/pharmacodynamic (PK/PD) studies of patients with PJI.

Investigating the Influence of Spinach Sauce in Modulating Serum Calcium in Osteoporotic Females

Background: The modulation of serum calcium levels through diet is a critical aspect of managing osteoporosis, particularly in postmenopausal women. Spinach, known for its high calcium content, offers potential benefits for bone health due to its rich nutrient profile. This study aimed to develop a spinach sauce, evaluate its consumer acceptability, and investigate its impact on serum calcium levels in osteoporotic females. Objective: To develop a nutritionally rich spinach sauce, assess its sensory acceptability, and evaluate its effectiveness in modulating serum calcium levels among osteoporotic females. Methods: The spinach sauce was formulated using various recipes to maximize calcium bioavailability. The preparation process involved controlled cooking techniques to preserve nutrients, followed by proximate composition analysis. A sensory evaluation was conducted with osteoporotic females and a control group using standard hedonic scales. Participants were instructed to incorporate the spinach sauce into their daily diet for a specified period. Serum calcium levels were measured before and after the intervention. Statistical analysis was conducted using SPSS version 25, controlling for covariates such as age, baseline dietary habits, and baseline serum calcium levels. Ethical approval was obtained, and informed consent was provided by all participants. Results: Treatment T2, containing 40% spinach and 60% mint, scored highest in sensory evaluation with color (8.94 ± 0.26), flavor (8.92 ± 0.30), taste (8.98 ± 0.27), texture (8.22 ± 0.29), and overall acceptability (8.94 ± 0.31). The proximate composition of the spinach sauce showed moisture (79.84%), crude protein (6.27%), crude fat (1.91%), fiber (0.57%), ash (4.21%), and nitrogen-free extract (10.27%). Serum calcium levels increased significantly in the spinach sauce group from 0.84 ± 0.01 to 1.03 ± 0.04, and in the combined spinach sauce and calcium supplement group from 0.69 ± 0.01 to 0.91 ± 0.07. ANOVA revealed significant effects of treatments (F = 1.99, p ≤ 0.01) and days (F = 41.96, p ≤ 0.01) on bone mineral density. Conclusion: The developed spinach sauce was nutritionally rich and well-received, particularly in treatment T2. It demonstrated potential in improving serum calcium levels among osteoporotic females, suggesting that dietary interventions with spinach could be a viable strategy for managing osteoporosis. Further research with larger sample sizes and longer durations is recommended to substantiate these findings.

Composition and functionality differences of oat protein concentrates: Potential of less refined concentrates obtained by wet milling

The objective of this study was to determine differences in composition and functionality for oat protein concentrates. This was achieved by comparing preparations extracted at different pH levels using either a twin screw press or alkaline extraction followed by isoelectric precipitation. Extraction by twin screw technology provided a higher protein yield compared to isoelectric precipitation. Analysis by SDS-PAGE revealed similar protein composition regardless of the extraction method or extraction pH except for extraction at pH 6. Extraction at a higher pH led to a higher protein purity and yield, while extraction closer to the isoelectric point of the protein resulted in less pure concentrates. All extracts were freeze-dried, and their composition and functionality were compared. Thermal analysis of the protein concentrates extracted by twin screw pressing showed a higher denaturation enthalpy compared to protein isolates prepared by isoelectric precipitation, suggesting that the native structure of the proteins is preserved to a higher extent. All protein fractions exhibited the typical U-shaped solubility profile, except for the concentrate extracted at pH 6, which showed an increase in solubility with increasing pH. Oat protein concentrates prepared by twin screw pressing had a higher affinity for binding to oil than to water, and this was also higher than for isoelectric precipitated protein extracts. Overall results demonstrate a potential for twin screw technology as a viable alternative to conventional wet extraction methods for producing less refined fractions from oats with tunable functional properties.

The feasibility and applicability of sequential extraction of high value-added biogenic materials from sewage sludge.

The sequential extraction routes of biogenic materials from sewage sludge (SS) were investigated. Physical methods (ultrasound, heating) and chemical methods (sodium hydroxide, sodium carbonate) were used to extract extracellular polymeric substances (EPS) and alginate-like extracellular polymers (ALEs) from SS. The residues after extraction were further subjected to physical methods (heating) and chemical methods (sulfuric acid, sodium hydroxide) for protein extraction. A comparison was made between sequential extraction routes and direct extraction of biomaterials from sludge in terms of extraction quantity, material properties, and applicability. The results showed that sequential extraction of biomaterials is feasible. The highest extraction quantities were obtained when using sodium carbonate for EPS and ALE extraction and sodium hydroxide for protein, reaching 449.80 mg/gVSS, 109.78 mg/gVSS, and 5447.08 mg/L, respectively. Sequential extraction procedures facilitate the extraction of biomaterials. Finally, suitable extraction methods for different application scenarios were analyzed.

GPSFun: geometry-aware protein sequence function predictions with language models.

Knowledge of protein function is essential for elucidating disease mechanisms and discovering new drug targets. However, there is a widening gap between the exponential growth of protein sequences and their limited function annotations. In our prior studies, we have developed a series of methods including GraphPPIS, GraphSite, LMetalSiteand SPROF-GO for protein function annotations at residue or protein level. To further enhance their applicability and performance, we now present GPSFun, a versatile web server for Geometry-aware Protein Sequence Function annotations, which equips our previous tools with language models and geometric deep learning. Specifically, GPSFun employs large language models to efficiently predict 3D conformations of the input protein sequences and extract informative sequence embeddings. Subsequently, geometric graph neural networks are utilized to capture the sequence and structure patterns in the protein graphs, facilitating various downstream predictions including protein-ligand binding sites, gene ontologies, subcellular locationsand protein solubility. Notably, GPSFun achieves superior performance to state-of-the-art methods across diverse tasks without requiring multiple sequence alignments or experimental protein structures. GPSFun is freely available to all users at https://bio-web1.nscc-gz.cn/app/GPSFun with user-friendly interfaces and rich visualizations.

Proteomics profiling reveals the detoxification and tolerance behavior of two bread wheat (Triticum aestivum L.) varieties under arsenate stress

Arsenic (As) contaminated irrigation water caused a significant buildup of its level in the agricultural soil and edible tissues of wheat. High levels of As negatively impact grain quality, wheat yield, and human health consequently. It is still unknown how wheat varieties respond to As stress at the proteomic level. Therefore, the present study aimed to deliver mechanistic details regarding the role of proteins in tolerance mechanism against As stress. Two wheat varieties (BARANI-70 and NARC-2009) were exposed to arsenate treatment (200 µM) in a hydroponic experiment to evaluate the impacts of arsenic stress using proteomics. Roots of both varieties were used for protein extraction, digestion, and LC-MS/MS analysis to identify differentially abundant proteins (DAPs). Furthermore, various bioinformatic tools were used to study subcellular localization, functional categories, and pathway analysis. The findings identified 67 DAPs in BARANI-70 (up-regulated=56; down-regulated=11) and 89 DAPs in NARC-2009 (up-regulated=34; down-regulated=55). Subcellular localization revealed significant up-regulation of DAPs in mitochondria and chloroplast for BARANI-70 but down-regulation in NARC-2009 under As stress. Functional analysis revealed significant upregulation of DAPs for glutathione, peroxidase, glutathione peroxidase, lactoylglutathione lyase, and glutathione-s-transferase in BARANI-70. Pathway analysis showed regulation of DAPs involved in tetrapyrrole biosynthesis and glycolysis-TCA particularly in BARANI-70 compared to NARC-2009. Furthermore, BARANI-70 showed better growth response under As stress compared to NARC-2009. Thus, better synthesis of stress-responsive DAPs and important pathways in BARANI-70 contributed towards its tolerance against As stress. The present research supports the use of tolerant varieties and identified protein biomarkers to enhance crop resilience against As stress.

Bio-based composite active film/coating from deccan hemp seed protein, taro starch and leaf extract: Characterizations and application in grapes

This study aimed to create a novel, cost-effective, and environmentally friendly food packaging film or coating using agricultural waste materials such as deccan hemp seeds and leaves. The process involved blending deccan hemp seed protein and leaf extract at an optimal ratio through a casting technique. Additionally, starch isolated from taro root was added into the protein-based film to enhance its structural, barrier, and mechanical properties. The introduction of bioactive compounds, like deccan hemp leaf extract, led to increase in antioxidant activity and enriching the film with beneficial phenolic compounds.The combination of leaf extract and starch with the protein film resulted in a homogeneous, dense, and smooth film matrix, as evidenced by scanning microscopy images. FTIR spectroscopy confirmed interlinkage among the various constituents in the film. Rheological analysis of the film-forming solution showed its shear-thinning behavior, with the storage modulus exceeding the loss modulus in the angular frequency range of 0.1 rad/s to 100 rad/s, indicating the film's elastic nature. Furthermore, the physical and optical attributes of the films were enhanced through the addition of starch and leaf extract.In a practical application, the film-forming solution was applied to grapes, leading to improved quality and extended shelf life for grapes stored under ambient conditions for ten days. Overall, this study's findings suggest that the use of deccan hemp seed protein-based packaging film holds promise as an emerging solution for enhancing the shelf life of vegetables and fruits, offering a sustainable and effective alternative for food packaging.

Sensory quality of emulsions prepared with the seaweed Ulva spp. or a derived protein ingredient

The sensory quality of seaweed, whether as a whole biomass or as a protein ingredient, plays a crucial role in its successful commercialization. This study explored the effect of different Ulva species, biomass washing, and pH-shift-based protein extraction on the sensory quality of emulsions with 0, 5, and 10 % oil. A trained panel assessed the sensory profile, complemented by analyses of volatile compounds, total ash, and amino acids. Saltiness emerged as the primary distinction between emulsions with unwashed U. linza and U. fenestrata, due to higher ash in the former. Washing U. fenestrata retained sensory qualities despite reduced ash and increased content of the lipid oxidation-marker pentanal. Protein extraction up-concentrated total amino acids 2.9-fold, and yielded emulsions with reduced particle sensation and grassy flavor, while bitterness, sourness, dark color, pentanal, hexanal, and 2-ethylfuran increased. Increased oil content of emulsions lowered their grassy odor which correlated with reduced hexanal content. Overall, these findings can contribute to the development of food products containing seaweed or protein ingredients thereof that match consumer preferences.

Surface activity of Lupinus angustifolius (blue lupine) seed extracts

Surface tension (γeq) of the seed extracts of four lupine cultivars showed values in the range 44.9–46.4 mN/m. The surface compression elasticity (E') of the adsorbed layers and foaming capacity (FC) also showed similar values (E' ∼ 30 mN/m, FC ∼ 100%). The effect of defatting prior to extraction at pH 8.5 depends on the solvent employed – hexane and dichloromethane improved the subsequent protein extraction yield, while ethanol reduced it. The effect of defatting on surface tension could be positive (for hexane and ethanol) or negative (for dichloromethane). Generally, defatting improved the surface compression rheological and foaming parameters. On the other hand, fractionation of the extracts obtained at pH 8.5 from hexane-defatted seeds did not improve significantly the surface activity parameters. Some improvement with respect to the unfractionated extracts was observed only for the extracts of undefatted seeds. γeq, E', E" and FC isotherms confirm the surfactant-like behavior of the lupine seed extracts.

Alkaline solubilization of microalgal protein and its impact on the functional properties of protein extract

Microalgal alternative proteins are increasingly recognized as a sustainable and promising source for future food production. Despite the widespread use of alkaline solubilization in protein extraction, its influence on the functional properties of microalgal protein extracts has received limited attention. This study marks the pioneering effort to assess the impact of alkaline (NaOH) solubilization on both the extraction process and the functional properties of Chlorella vulgaris protein extract (CVPE) obtained through isoelectric precipitation. With the gradual escalation of alkaline concentration from 0 to 0.7 M, there was a notable improvement in protein extraction efficiency, increasing significantly from 6.22 % to 56.23 %. However, elevated NaOH concentrations resulted in protein degradation, as evidenced in SDS-PAGE studies. Alkaline solubilization exhibited a positive impact on various functional properties of CVPE. It enhanced solubility, water absorption capacity, foaming capacity and stability, as well as emulsifying activity and stability. However, there was a slight decrease in oil absorption capacity with increasing NaOH concentration. Notably, the maximum solubility, oil adsorption capacity, foaming capacity, and emulsion activity of CVPE were 2.3-, 1.8-, 2-, and 1.3-fold higher, respectively, than those of commercial soy protein isolate (SPI). This highlights the effectiveness of alkaline solubilization in modifying C. vulgaris protein and emphasizes the high potential of CVPE as a functional food ingredient.

Wheat gluten structure and (non–)covalent network formation during deep-fat frying

The aim of this work was to investigate wheat gluten protein network structure throughout the deep-frying process and evaluate its contribution to frying-induced micro- and macrostructure development. Gluten polymerization, gluten-water interactions, and molecular mobility were assessed as a function of the deep-frying time (0 – 180 s) for gluten-water model systems of differing hydration levels (40 – 60 % moisture content). Results showed that gluten protein extractability decreased considerably upon deep frying (5 s) mainly due to glutenin polymerization by disulfide covalent cross-linking. Stronger gliadin and glutenin protein–protein interactions were attributed to the formation of covalent linkages and evaporation of water interacting with protein chains. Longer deep-frying (> 60 s) resulted in progressively lower protein extractabilities, mainly due to the loss in gliadin protein extractability, which was associated with gliadin co-polymerization with glutenin by thiol-disulfide exchange reactions. The mobility of gluten polymers was substantially reduced during deep-frying (based on the lower T2 relaxation time of the proton fraction representing the non-exchanging protons of gluten) and gluten proteins gradually transitioned from the rubbery to the glassy state (based on the increased area of said protons). The sample volume during deep-frying was strongly correlated to the reduced protein extractability (r = –0.792, p < 0.001) and T2 relaxation time of non-exchanging protons of gluten proteins (r = –0.866, p < 0.001) thus demonstrating that the extent of gluten structural expansion as a result of deep-frying is dictated both by the polymerization of proteins and the reduction in their molecular mobility.

Apparent digestibility and nutritional status of capuchin monkeys (Sapajus sp.) under human care.

Studing the nutritional needs and dietary habits of primates is essential to ensure their health and well-being. This includes the understanding of the use of nutrients and its correlation with health parameters. Diet and nutritional parameters of 13 captive capuchin monkeys (Sapajus sp.) were assesed. Apparent digestibility of dry matter and nutrients were evaluated. Nutritional status was established based on body condition score (BCS) and muscle mass score (MMS). High apparent digestibility coefficients (ADC) were observed for crude protein and ether extract, but low for minerals and crude fiber. The ADC of EE and CF were related to MMS, and the biochemical parameters did not correlate with the AD coefficients obtained in the group. The nutritional status of the animals remained inadequate in 84.6% of the individuals, suggesting a reformulation of the diet and nutritional management.