Wheat Gluten Research Articles

Technological aspects of managing the structural and mechanical properties of wheat bread crumb

This work is dedicated to the study of the structural-mechanical properties of wheat bread crumb 12 hours after baking and then every 24 hours during 108 hours of storage. The basis of this investigation was the study of the starch retrogradation process, which is a transfer of the amorphous structure of starch grains into the crystalline state, which predetermines an increase in the values of the hardness parameters and hardness index. The aim of the work was investigation of an effect of the state of carbohydrate-amylase and protein-proteinase complex of wheat flour by introduction of wheat malt and dry gluten on the structural-mechanical properties of crumb of bakery products and their staling rate during storage. In this study, the authors used baker’s wheat flour of the highest grade, wheat malt, dry gluten, bread from baker’s wheat flour of the highest grade that was made using the straight dough method by the experimental laboratory baking. The authors established an effect of dosing wheat malt and dry wheat gluten on changes in the water absorption of wheat dough in the process of mixing, on its rheological properties, on the structural-mechanical properties of crumb of wheat bread made by the experimental laboratory baking as well as on the rate of its staling during storage. The optimal dosage of wheat malt was 5%, which ensured the falling number equal to 235 s. The dose of dry gluten of 3% ensured the total gluten content in dough of 31.3%, dough moisture of 43.1% and dough consistency equal to 640 FU. Simultaneous introduction of wheat malt and dry wheat gluten ensured a decrease in the hardness index of wheat bread crumb by 55% and the rate of its staling by 3.3 times.

Gelation and dough‐forming properties of canary seed protein concentrate in comparison with commercial soy protein concentrate and vital wheat gluten

AbstractBackground and ObjectivesIn this study, a lab‐scale process was developed to aqueously de‐oil canary seed (yellow and brown‐seeded) flour and derive a protein concentrate. The protein concentrates prepared were evaluated for their gelation and bread dough‐forming properties.FindingsThe aqueous process successfully reduced the oil content in both yellow‐seed and brown‐seed roller‐milled flour. The protein concentrate prepared from yellow‐seed flour and brown‐seed flour had 74.9% and 68.6% purity (dry weight basis), respectively. Proteins showed high resistance to thermal denaturation (peak denaturation at 107°C). It was found that the least gelation concentration of both protein concentrates was 16% (w/w). There were no significant differences in viscoelastic properties and water holding capacity between the protein gels of these two canary seed types and the addition of salt did not noticeably improve these properties. Compared to canary seed, commercial soy protein showed better gelation properties. Both yellow and brown canary seed protein showed a good potential for improving bread dough strength when incorporated into a low‐gluten‐strength wheat flour and was comparable to commercial vital wheat gluten at 1%–3% (w/w) inclusion levels.ConclusionsThe new canary seed protein ingredients prepared by the solvent‐free aqueous‐based process hold good potential for application in food formulation based on their gelation and bread dough‐forming properties.Significance and NoveltyThe gelation and dough‐forming properties of canary seed were not previously studied; therefore, this study provides an insight into those properties for potential food applications for canary seed proteins, which is important for canary seed market diversification as a novel protein source.

Effects of Mixing and Large-Amplitude Oscillatory Shear Deformations on Microstructural Properties of Gliadin and Glutenin as Captured by Stop-Flow Frequency Sweeps in Small-Amplitude Oscillatory Shear.

Gliadin and glutenin extracted from vital wheat gluten were studied using Large Amplitude Oscillatory Shear (LAOS) followed by stop-flow frequency sweep tests after being subjected to short (4 min) and prolonged (60 min) mixing times. The LAOS tests were conducted at up to two different strain amplitudes (γ: 0.1%, 200%; ω: 10 rad/s) to apply small and large deformations to the gliadin and glutenin after mixing for different time periods. Frequency sweep tests (ω: 0.01-100 rad/s, γ: 0.06%) revealed an increase in the elasticity of gliadin with respect to an increasing mixing time, as evidenced by a robust increase in G'(ω), coupled with a less robust increase in G″(ω). Consistent with the increase in elasticity, a progressively lower tanδ(ω) and G'(ω) slope were observed for the gliadin that underwent 60 min of mixing followed by large LAOS deformations. However, G'(ω), G″(ω), and η*(ω) remained constant for glutenin as the mixing time increased. Elastic decay with an increase in tanδ(ω) was found for glutenin when subjected to prolonged mixing followed by large LAOS deformations, which became apparent at high frequencies. The stop-flow LAOS (non-linear region)-frequency sweep (linear region) tests provided an understanding of how exposure to different mixing times and LAOS deformations of different magnitudes influence the mechanical/rheological properties of the main gluten proteins.

Strong, tough self-healing multi-functional sodium alginate-based edible composite coating for banana preservation

Edible coatings are a new green technology for preventing the rotting of fruits and extending their shelf lives. However, during storage, respiratory processes can generate large amounts of water, causing the dissolution of these coating. Furthermore, these coating can be mechanically damaged. Therefore, the development of strong, tough, waterproof and self-healing edible coatings is highly desirable. Herein, gluconolactone was slowly oxidized to generate gluconic acid, which was further used to protonate amino groups in wheat gluten (WG), forming strong electrostatic interactions, hydrogen bonds and ester bonds between soy hull nanocellulose (SHNC) and sodium alginate (SA). The introduction of WG and SHNC improved the mechanical strength, hydrophobicity and water retention of the composite film from 28 MPa, 33.2° ± 1.18° and 19.43° ± 0.83° to 60 MPa, 45.13° ± 1.53° and 41.47° ± 0.96°, respectively. Further, the composite film exhibited excellent self-healing, UV resistance and gas-barrier properties. Banana preservation experiments showed that at 25 °C and 50 % RH, the composite coating effectively slowed the mass loss and softening of bananas, delayed the browning of banana peels and ripening of fruit pulp, and extended the shelf life of bananas to 7 days. Therefore, this study provides a new perspective for the preparation of a new, strong, tough, waterproof and self-healing multi-functional edible coating with high potential for the preservation of perishable fruits.

Co-stabilization effects of gluten/carrageenan to the over-heated myofibrillar protein: Inhibit the undesirable gel weakening and protein over-aggregations

High-temperature (120 °C) sterilization is an indispensable process for manufacturing ready-to-eat surimi products, yet risking the denaturation of their myofibrillar proteins (MP), thus significantly reducing the gelling properties. To resolve this problem, herein, a synergistic co-strengthening strategy was designed. The negatively charged polysaccharide carrageenan (CG) was introduced into MP simultaneously with wheat gluten, followed by 120 °C thermal treatment for 30 min. A substantial enhancement in mechanical strength, up to four times greater (from 9.86 to 42.38 g·cm), was observed for MP gels, which even surpassed that subjected to conventional gelation processes at 90 °C (36.53 g·cm). Gels that were concurrently added with gluten and CG exhibited porous networks, uniform water distribution, and improved water holding capacity. Accordingly, over-aggregation behaviors of MP were restricted, as evidenced by their reduced particle sizes and polymer dispersity index. Other heat-induced protein deteriorations at 120 °C, i.e., changes of secondary structures and disulfide bonding conformations, were also alleviated. By varying the CG types, it was shown that the κ-CG/gluten-added MP achieved highest gel strength, while the ι-CG/gluten combination may better stabilize the moisture in gel networks. This study introduces a co-reinforcement paradigm and scientific insights to the quality improvement of ready-to-eat meat products.

Impact of hydrocolloids on 3D meat analog printing and cooking

This study investigated the effects of hydrocolloid addition on three-dimensional (3D) printing and cooking of plant ingredients-based meat analog (MA). The MA inks were formulated with soy protein isolate, wheat gluten, canola oil, water, and hydrocolloids (xanthan gum, pectin, hydroxypropyl methylcellulose, guar gum, locust bean gum) at a ratio of 22:12:15:88:2. Formulated inks were used to create a specific 3D cylindrical model geometry and the printed structure were subjected to air frying (AF:180°C, 15 min) and infrared heating (IR:180°C, 15 min). Results showed that the MA ink’s viscosity (3871–5482 Pa. s), 3D printing rate (0.34–0.39 g.sec−1), printing error (2.51–10.37 %), and printing precision (81.97–97.27 %) were significantly (p<0.05) impacted by the incorporation of hydrocolloids. The dimensional stability (63.17–98.58 %), and cooking loss (6.70–17.41 %) were greatly impacted by both the hydrocolloids and post-printing cooking methods. Moisture (1.71 db) and fat (0.28 db) content of uncooked 3D printed MA were identical, whereas, differences in color attributes (L value:80.21–98.88, a value:0.01–0.13, b value:0.11–2.11) among the studied hydrocolloid added samples were observed. Moisture, fat, and color traits of 3D printed meat-analogs were significantly (p<0.05) impacted by post-printing cooking methods (AF, IR). During post-printing cooking, the loss of mass (moisture, fat) and changes in color tones were associated with the types of hydrocolloids incorporated in formulating the 3D printing ink. Surfaces and internal structure, mass loss, chemical profile, and glass-transition-temperature of 3D printed meat-analogs were significantly (p<0.05) impacted by both the type of incorporated hydrocolloids and post-printing cooking methods.

Improvement and quality evaluation of gluten-free cake supplemented with sweet potato flour and carrot powder

Celiac disease and wheat allergy are immune-responsive small bowel disorders that respond solely to the ingestion of gluten-fortified wheat or wheat flour. As a result, for those who are allergic to wheat flour or gluten, the primary treatment is a gluten-free or wheat-free diet. The goal of this research is to develop a gluten-free cake with sweet potato and carrot powder, as well as to examine the Proximate analysis, mineral content, physical properties, and microbiological qualities determined using standard analytical procedures. To make cakes, instead of wheat flour, a combined formulation of 80 % sweet potato flour and 20 % carrot powder, 60 % sweet potato flour and 40 % carrot powder was incorporated into the cake ingredients. Quality evaluation of sample cakes was performed by physicochemical and storage properties. The proximate analysis of the data revealed that the cakes that were created contained adequate levels of protein, fiber, and carbohydrates with percentages ranging from 8.12 to 8.25 %, 3.19–4.19 %, and 36.03 to 38.25 %, respectively. Additionally, an appreciable amount of potassium, calcium, magnesium, phosphorus, and iron have been found in gluten-free cakes. There was color to the gluten-free cakes; L*, a*, and b* ranged from 42.66 to 43.60, 10.03 to 11.21, and 21.81 to 23.28, respectively. There is an assurance of a good color property because the hue and chroma values varied from 11.74 to 25.83 and from 41.02 to 78.03, respectively. The water activity (aw) value ranged from 0.854 to 0.870, which increased from 0.879 to 0.901 during storage. Furthermore, the microbial analysis revealed that the total viable count of all samples remained within the acceptable range after 8 days of storage. The findings of this study show that carrot powder and sweet potato flour can be used to overcome the limitations of gluten-free cakes and improve their nutritional quality.

Regulating the interaction between protein and starch in noodles through heat loss: Used to improve the edible quality of noodles

The impact of heat loss during water-cooling process on the edible quality of cooked noodles currently remains unclear. This study aimed to explore the effects of different water-cooling times (0, 20, 40, 60, 80, 100, and 120 s) on changes in gluten and starch structures and their impact on the sensory evaluation and texture of noodles. Results showed that the control group had a higher core temperature, while the core temperature of the noodles equilibrated with the water temperature after water-cooling for 100 s. Within the range of 20–100 s of water-cooling time, a sudden drop in the core temperature of the cooked noodles caused the gluten conformation to transition toward more compact β-sheets. Surface hydrophobicity decreased, while S-S and hydrogen bonds increased. The microstructure of the noodles became more compact, reducing gaps between protein and starch molecules. Small-angle X-ray scattering and atomic force microscopy analyses demonstrated that gluten chains aggregated after water-cooling, resulting in increased chain width and height. The wheat gluten protein structure transitioned from a disordered state to a random coil. Ultimately, the hardness, springiness, and chewiness of the noodles gradually increased. Water distribution results revealed that the free water content of the noodles increased after 120 s of water-cooling, enhancing the hydration between protein and water molecules but decreasing the noodle texture. According to X-ray diffraction and differential scanning calorimeter analyses, heat loss did not alter the gelatinized starch crystal structure of noodles. Therefore, changes in core temperature were the primary cause of gluten structural changes prior to 100 s of water-cooling. After 120 s of water-cooling, increased hydration between noodle surface gluten and water negatively affected the edible quality of noodles. This study provides theoretical data on noodle edible quality and is of significant practical importance.

Unveiling the structural and physico-chemical properties of glutenin macropolymer under frozen storage: Studies on experiments and molecular dynamics simulation

Glutenin macropolymer (GMP) plays an important role in wheat gluten fractions, and extensively presents in the frozen dough. However, the effects of freezing treatment on GMP remain not abundantly understood. In this study, we investigated the structure and physico-chemical properties of GMP under frozen storage through experimental methods and bioinformatics algorithms. Results revealed that freezing treatment weakened the structure and properties of GMP to varying degrees, and GMP might have tolerance to short-term freezing storage. During frozen storage, portions of α-helix in GMP were converted into β-turn and random coil, slight changes in the tertiary structure, and its surface hydrophobicity increased by 4.8 %. SDS-PAGE profiles indicated that the depolymerization behavior mainly occurred above the Mw of 70.0 kDa. Slight changes were observed in the content of free thiol groups and disulfide bonds during frozen storage. Combination of fluorescence spectroscopy and intermolecular interactions suggested that hydrogen bonds and hydrophobic interactions were probably important indicators for evaluating the deterioration of GMP. Frozen storage resulted in an unfolded and open protein network. Moreover, freezing treatment led to a main conversion from strongly bond water to weakly bond water. However, no significant changes in water distribution were observed during the first 7 days of frozen storage. The viscoelastic loss of GMP primarily occurred in the first fourteen days, but tan δ did not significantly increased, indicating that protein has not been seriously deteriorated. Molecular dynamics simulation further supplemented and validated these experimental results from molecular level through analysis of root mean square deviation, root mean square fluctuation, solvent-accessible surface area, radius of gyration and the number of hydrogen bonds.

Environmental impacts of the filamentous fungi Paecilomyces variotii (PEKILO®) as a novel protein source in feeds for Atlantic salmon (Salmo salar)

The present study investigated environmental impacts associated with greenhouse gas (GHG) emission, economic Fish in Fish out ratio (eFIFO), waste outputs, and food-feed competition of feeding diets containing the filamentous fungus Paecilomyces variotii (PEKILO®) to Atlantic salmon (Salmo salar) pre-smolts. To achieve this, a feeding trial was conducted using four experimental diets. The control diet was based on fishmeal, soy protein concentrate, and wheat gluten meal. Diets 1, 2, and 3 were formulated so that P. variotii replaced 5, 10, and 20 % of the crude protein (CP) content of the control diet originating mainly from fishmeal, soy protein concentrate, and wheat gluten meal. Dietary inclusion of P. variotii affected simulated environmental indices such as GHG emission (P < 0.001); this index was P. variotii-dose-dependent, as illustrated by negative linear models (P < 0.001, adjusted R-squared = 0.96). Dietary inclusion of P. variotii was negatively correlated with eFIFO (P < 0.001, adjusted R-squared = 0.82). Dietary inclusion of P. variotii reduced food-competition feedstuff (FCF) in the diets (P < 0.001), as well as the amount of FCF to produce one kg of Atlantic salmon (P < 0.001). Relative to the control diet, solid nitrogen waste output, expressed as g kg−1 fish produced, was increased (P < 0.0001) in fish fed Diet 3. Conversely, linear decreases in solid phosphorous, magnesium and potassium (P < 0.0001) wastes expressed as g kg−1 fish produced were associated with increasing dietary inclusion of P. variotii. Likewise, linear decreases in dissolved nitrogen, magnesium, and potassium (P < 0.0001) wastes were observed with increasing replacement of the CP content of the control diet with P. variotii. Based on this assessment, P. variotii is a relevant alternative protein source with a low environmental footprint for use in Atlantic salmon feeds. Future novel feeds for Atlantic salmon should expand the use of alternative protein- and lipid-rich materials with a low ecological footprint that are produced according to a circular bioeconomy principle and utilize non-food-competing feedstuff (NFCF) such as P. variotii to move the industry toward sustainability.

Maillard reacted wheat gluten and polydextrose complex enhances the emulsifying properties and stability of Pickering emulsion

This study aims to explore the characteristics and stability of Pickering emulsion based on the Maillard reaction products of polydextrose (PDX) and gluten. The effects of the PDX:gluten ratio (from 0.0:1 P0.0G1 to 2.4:1 P2.4G1) during Maillard reaction on Pickering emulsion quality were examined. The degree of PDX grafting to gluten increased from 0.51%±0.05% to 18.99%±0.98% when the PDX:gluten ratio increased from 0.2:1 to 2.2:1. Scanning electron microscopy and infrared spectroscopy confirmed the structural change and covalent interaction of PDX–gluten conjugate. The P2.2G1 conjugate showed a higher emulsification activity (1.82±0.04 m2/g) compared with P0.0G1 (0.97±0.05 m2/g). The particle size, ζ-potential value and confocal laser scanning microscopic image of PDX–gluten conjugate-based emulsion were compared with those of gluten-based emulsion to illustrate the stability role of PDX–gluten conjugate in the interfacial layer of Pickering emulsion. This study demonstrated that the Maillard reacted gluten–PDX conjugate was a potential stabilizer for Pickering emulsions. These findings provided a foundation knowledge for the construction of Pickering emulsion based on PDX–gluten conjugates.

Unveiling the binding mechanism between wheat arabinoxylan and different molecular weights of wheat glutenins during the dough mixing process

Water-soluble arabinoxylans (AX) is an important dietary fiber in wheat bran that influence the gluten network. However, a comprehensive understanding of the mechanism remains unclear. This study compared the interactions between AX and high/low molecular weights of glutenin (HMW/LMW) and found that AX-HMW developed a more uniformed structure than AX-LMW. The optimized property was found at 8% AX (AX8-HMW) when the disulfide bonds, foaming and emulsifying properties reaches highest, which is better than the optimized AX4-LMW. However, higher AX ratio led to poor properties due to AX self-aggregation. The enhancement property can be associated with the formation of molecular complexes. Both HMW and LMW can capture and encapsulate AX to form stable structures, with the binding strength of AX-HMW being stronger than that of AX-LMW, resulting in macroscopic properties. Our findings clarify the interaction mechanism between AX and different molecular weight of glutenins which contributes to understand the role of AX in the dough mixing process.

Acetated starch inclusion to tailor the hierarchical structure and sol-gel features of middle gluten wheat starch-based binary matrices

Acetated starch inclusion to tailor the hierarchical structure and sol-gel features of middle gluten wheat starch-based binary matrices

Establishing a novel covalent complex of wheat gluten with tea polyphenols: Structure, digestion, and action mechanism

Plant-based proteins represent a more sustainable alternative, the approaches to modify and enhance their functionality and application are focused on. Covalent interaction could significantly modify the structure and function properties of protein. This study investigated the effects of covalent interaction between wheat gluten and tea polyphenols on the structure, aggregation, stability, and digestive properties of their covalent complex, as well as the possible action mechanism. The results showed that tea polyphenols could interact with gluten via covalent bonds (CN and/or CS), while tea polyphenols also acted as a bridge connecting gluten molecules, thus making covalent complex to show the larger particle sizes. This covalent interaction significantly changed the secondary structure, tertiary structure, and surface hydrophobicity of gluten. Moreover, covalent complex exhibited the high polyphenols bioaccessibility during in vitro digestion. The peptide bonds of covalent complex were mainly broken in gastric digestion, while the covalent bonds between tea polyphenols and gluten were completely destroyed in intestinal digestion. In addition, their digestates exhibited excellent antioxidant capability. All results suggest that wheat gluten have potential to prepare functional carrier for transporting active compounds and protecting them during digestion.

Arbuscular mycorrhizal fungi affected soft wheat quality properties and nutritional index by regulating the composition and secondary structure of protein

Arbuscular mycorrhizal fungi (AMF) inoculation has important regulatory influence on plant growth and nitrogen uptake, which are intimately associated with soft wheat yield and quality. The study aimed to investigate the impact of AMF inoculation on soft wheat grain yield, protein compositions, protein quality, secondary structure of gluten, dough properties and biscuits baking quality. In this study, AMF inoculation significantly increased grain yield. AMF inoculation decreased grain protein content by 5.1%, glutenin content by 8.5%, GMP by 14.3%, and HMW-GS by 8.8% compared with CK. Conversely, AMF inoculation increased the ratio of gliadin/glutenin. Further analysis showed AMF treatment had a looser gluten network than CK, significantly reduced β-sheet and β-turn content, while α-helix content increased. The nutritional index of grain protein was slightly reduced under AMF inoculation, yet the biological value was improved. Reduced wet gluten content, gluten performance index and dough development time under AMF treatment through regulation of soft wheat protein composition and gluten protein structure. Therefore, biscuits in AMF treatment showed reduced thickness, hardness, significantly greater spread ratio and sensory score compared with CK. These indicate that AMF application would be a beneficial agronomic practice to synergistically optimize yield and grain quality in soft wheat.

Low-moisture extruded mung bean protein isolate and wheat gluten: Structure, techno-functional characteristics and establishment of rehydration kinetics of the products

Low-moisture extruded products provide excellent shelf-life and stability, making the exploration of new formulations with various proteins highly valuable. This study prepared and compared products with different ratios of mung bean protein isolate (MPI) to wheat gluten (WG) (10:0, 9:1, 8:2, 7:3, 6:4, and 5:5). Results showed significant improvements (P < 0.05) in L∗-value and product quality with increasing WG ratios, peaking at an MPI/WG ratio of 7:3. Increased WG also enhanced protein cross-linking aggregation, as evidenced by changes in particle size, secondary structure, and fluorescence spectra. However, excessive WG (MPI/WG = 6:4) adversely affected product structure and techno-functional characteristics. Rehydration kinetics were best described by the Peleg model, with rehydrated products showing decreased hardness (291.25 N) and chewiness (227.45 N), but increased tensile resistance (P < 0.05). Eleven quadratic polynomial equations were developed to predict color and techno-functional characteristics based on WG percentage (0–50%). The findings provide a theoretical basis for expanding the application of MPI in new low-moisture extruded products.

Quantitative assessment of the effects of rising temperature on the grain protein of winter wheat in china and its adaptive strategies

With advancements in genetics and technology, wheat yields have continuously increased, but grain quality has remained stagnant or even decreased in recent decades. The effects of temperature on the future grain quality of winter wheat in China are unknown. This study used an improved WheatGrow model, along with two future temperature scenarios, to quantify the regional impacts of temperature increases on grain protein in China and aimed to find effective strategies to adapt to the impact of temperature increases on quality. Compared with those in the baseline period, the protein concentration of wheat grains in the main winter wheat production region of China increased by 0.27% and 0.41% under the 1.5 ℃ and 2.0 ℃ temperature increase scenarios, respectively. However, the grain protein concentrations in the Sichuan Basin of Medium and Weak Gluten Wheat Subregion (Ⅴ) decreased. The temperature rise was estimated to increase the proportion of strong gluten-type wheat but reduce the proportion of medium gluten-type wheat, with the proportion of weak gluten-type wheat changing slightly. Advanced planting date was projected to increase the grain protein concentration in the Northern Strong Gluten Wheat Subregion (Ⅰ), the Northern of Huang-Huai Strong and Medium Gluten Wheat Subregion (Ⅱ), the Southern of Huang-Huai Medium Gluten Wheat Subregion (Ⅲ) and the Yangzi River of Medium and Weak Gluten Wheat Subregion (Ⅳ), whereas a delayed planting date reduced the protein concentration in subregions Ⅰ, Ⅱ, and Ⅲ. In addition, the grain protein concentration was not significantly affected in the higher high-temperature threshold varieties in the southern winter wheat production region under the global warming scenarios. However, if more strong gluten-type wheat is required in the northern China in the future, varieties with lower high-temperature thresholds can be selected without considering wheat yields. Moreover, increasing the nitrogen fertilizer application rate could further increase the wheat protein concentration under future warming scenarios, and the protein concentration of wheat was more sensitive to the nitrogen fertilizer application rate in the northern winter wheat production region than in the southern region. These findings are crucial for improving grain quality across different wheat production regions of China in the future.

Structure, antioxidant properties and AGEs (advanced glycation end products) formation of modified wheat gluten protein after enzymatic hydrolysis and Maillard reaction

The study aimed to investigate the effect of the Maillard reaction on functional properties, including structural changes, antioxidant capacity, and advanced glycation end products (AGEs) formation in gluten protease hydrolysates. The results demonstrated that the contents of free amino groups and sulfhydryl groups in modified gluten decreased as the Maillard reaction time extended. Meanwhile, there was an increase in the contents of fluorescent AGEs, Nε-(carboxymethyl) lysine and Nε-(carboxyethyl) lysine. Enzymatic hydrolysis accelerated protein glycosylation reaction, and alkaline protease-modified conjugates showed higher antioxidant activities compared to other two proteases. Additionally, surface hydrophobicity decreased with the increase of glycosylation degree in all three conjugates. Furthermore, a positive correlation was found between AGEs content and antioxidant activities as well as β-sheet content, while a negative correlation existed with α-helix content and free amino/sulfhydryl (SH) groups. This study contributes to tracking harmful AGEs in heat-processed wheat foods and provides insights for developing natural active glycosylated peptides.

Interfacial and foaming properties of plant and microbial proteins: Comparison of structure-function behavior of different proteins

Many plant proteins are amphiphilic molecules that can adsorb to air-water interfaces and form protective coatings around gas bubbles. In this study, the composition, structure, physicochemical properties, air-water interfacial properties, and foaming properties of 16 plant and microbial proteins were characterized. We found a correlation between the composition, structure, physicochemical properties, and foaming properties of the proteins. The foaming capacity of them showed a highly significant positive correlation (p ≤ 0.01) with their foaming stability, α-helix content, surface hydrophobicity, and free sulfhydryl content. The foaming capacity and foaming stability showed highly significant negative correlations with disulfide bond content (p ≤ 0.01). We found wheat gluten protein (WGP) and mung bean protein (MBP) had higher foaming capacity (102.67 ± 8.08 % and 89.33 ± 4.72 %), which could be attributed to higher surface hydrophobicity (179.68 ± 1.40 and 130.28 ± 1.41) and larger contact angle (82.369 ± 0.016° and 82.949 ± 0.228°).

Full-fat black soldier fly larvae meal and yellow mealworm meal: Impact on feed protein quality, growth and nutrient utilization of Atlantic salmon (Salmo salar) post smolts

The shift towards insect-based alternatives in aquafeeds stems from the need to reduce the carbon footprint associated with the ingredients used in salmon feeds. In the present study, we describe the effects of full-fat insect meal incorporation on amino acid derivatives in feeds and the growth performance and nutrient utilization of Atlantic salmon post-smolts fed insect meals. A 74-day growth trial was conducted employing 520 fish (143 ± 12.8 g); these fish were fed either a control diet (CO) that contained 20 % fishmeal, 20 % soy protein concentrate (SPC), 14 % wheat gluten, 19 % plant raw materials, 13 % fish oil and 6 % rapeseed oil, or one of four insect meal diets, prepared with either 5 % and 10 % black soldier fly larvae meal (BS5, BS10) or 15 % and 30 % mealworm meal (MW15, MW30), by substituting mainly SPC, wheat gluten and rapeseed oil. The inclusion levels of BS and MW were determined based on their distinct chemical compositions, specifically their lipid content. As regards the results, HPLC-based high-throughput data on amino acid derivatives revealed the following: carboxymethyllysine was significantly higher in the MW30 feed than in BS5, BS10 and MW15 feeds; carboxyethyllysine was higher in the MW15 and MW30 feeds compared to the others; furosine was lower in the MW15 feed compared to the CO, BS5 and MW30 feeds. Regarding the effect of the insect meals on Atlantic salmon post-smolts, their inclusion had no significant effect on feed conversion ratio, health indicators and the retention efficiency of macronutrients. Apparent digestibility coefficients (ADC) of dry matter, lipid, ash and energy were not significantly different. However, protein digestibility in the 30 % MW group (80.4 %) was significantly lower (P ≤ 0.05) compared to the control and BS5 group (84.5 %). Furthermore, the ADC of protein was found to decrease linearly with increasing levels of insect meals, with MW showing a significant relationship (adjusted r2 = 0.77, p = 0.014). Overall, our study highlights the efficacy of 5 and 10 % BS and 15 % MW as ingredients in the feeds of Atlantic salmon. Other focal points included the undesirable amino acid derivatives and a reduction in protein digestibility associated with 30 % of MW in the diet of Atlantic salmon. Hence, future investigations should focus on the effects of feed processing conditions on the protein quality of mealworm before suggesting higher inclusion levels to the feed industry.