Influence of the Mixture of Carrageenan Oligosaccharides and Egg White Protein on the Gelation Properties of Culter alburnus Myofibrillar Protein under Repeated Freezing-Thawing Cycles

Preparation, structure characterization and improved thermo-reversible gel properties of covalent conjugation of marine oligosaccharides/salt-soluble pea protein induced by cold plasma treatment

Plant protein-based thermo-reversible gels are essential for meeting the dietary nutritional needs of the elderly and individuals with dysphagia. However, high hydrophobic globulin content and heat-induced denaturation often hinder gel formation. In this study, salt-soluble pea protein isolate (SPPI) was extracted via ammonium sulfate precipitation, and cold plasma (CP) was used to conjugate SPPI with marine oligosaccharides, including chito-oligosaccharides (COS), carrageenan oligosaccharides (CAS), alginate oligosaccharides (AOS) and agaric oligosaccharides (AGS). This approach achieved a maximum grafting degree of 17.89 % and facilitated the thermo-reversible gelation of SPPI. The interaction mechanisms between SPPI and marine oligosaccharides and their effects on the thermo-reversible gels' functional properties were investigated. COS/SPPI-CP exhibited enhanced solubility, conductivity, reduced particle size. Structural analyses revealed increased environmental polarity, enhanced hydrogen bonding, stronger disulfide bonds and reduced hydrophobic interactions, hence indicating a shift towards a more hydrophilic SPPI structure after oligosaccharide conjugation. CP treatment improved gel thermo-reversibility while reducing hardness, adhesiveness, and chewiness, with COS/SPPI-CP showing the lowest values for these properties. Adding 0.3 % NaCl maintained thermo-reversibility, supporting safe swallowing and adequate nutritional intake. These findings contribute to developing pea protein-based supplements for individuals with dysphagia.

Characteristics of OSA modified starch-based Pickering emulsion and its application to myofibrillar protein gel

BACKGROUND

Pickering emulsions prepared with octenyl succinic anhydride-modified starch (OSAS) show significant promise as replacements for animal fat. However, the underlying mechanism of incorporating an OSAS-based Pickering emulsion into a myofibrillar protein (MP) gel and its impact on the gel properties remain poorly understood. In this study, the effects of OSAS at varying concentrations (0-10.0 g kg-1) on the stability of Pickering emulsion and the resultant gel properties of MP were investigated.

RESULTS

Emulsion stability was assessed using a stability analyzer, revealing a significant enhancement with increasing OSAS concentration. Compared with MP gel, the incorporation of the OSAS-based Pickering emulsion markedly improved the texture of the composite gels, increasing the gel hardness from 0.28 to 0.66 N. Moreover, water-holding capacity of composite gels rose from 28.5% to 61.2%, with a notable increase in immobilized water and a decrease in mobilized water. Rheological analysis revealed that the interactions of modified starch with MP and water molecules bolstered the elastic modulus of the gels. Additionally, the presence of OSAS-stabilized emulsions led to reduced surface hydrophobicity and sulfhydryl content of proteins in the gels, while partially inhibiting protein oxidation.

CONCLUSION

OSAS, notably at a high concentration, improved the physical stability of Pickering emulsion and the properties of MP gel. This research provides fundamental insights for the development of high-quality emulsified meat products. © 2024 Society of Chemical Industry.

Influence of dietary resveratrol supplementation on integrity and colloidal characteristics of Myofibrillar proteins in broiler chicken breast meat

Abstracts This study was designed to elucidate the impact of dietary resveratrol (RES) supplementation on the free radical activity within the breast muscle of broiler chickens and to assess its effects on the structural and colloidal attributes of myofibrillar proteins (MPs). A total of 180 1-day-old male AA broiler chickens was divided to 2 groups (a CON group fed a control diet and a RES group fed the control diet supplemented with 400 mg/kg RES), each with 6 replicates and 15 chickens per replicate. The feeding test lasted for 6 weeks. The findings indicate that RES, recognized for its potent antioxidant properties, markedly diminished free radical activity, thereby curtailing the oxidative degradation of MPs and augmenting the integrity of their conformational structure. The intricate MP conformation is pivotal in dictating the functional attributes of the protein colloid. RES supplementation was observed to diminish the mobility of water molecules, thereby enhancing the stability of the colloidal system and improving the water-holding capacity and the visual appeal in terms of whiteness of colloid. Concurrently, the stabilization of the protein structure facilitated an increase in the intermolecular cohesive forces within the colloid, resulting in a denser and more stable microstructure, which significantly bolstered the mechanical strength of the colloid. In summary, the incorporation of RES as a dietary supplement in poultry feed presents a promising strategy to fortify the stabilization of proteins in chicken breast meat, offering a valuable alternative for the production of high-quality poultry meat products.

Effects of Modified Oil Palm Kernel Expeller Fiber Enhanced via Enzymolysis Combined with Hydroxypropylation or Crosslinking on the Properties of Heat-Induced Egg White Protein Gel

Due to its poor hydration properties, oil palm kernel expeller dietary fiber (OPKEDF) is rarely used in the food industry, especially in hydrogels, despite its advantages of high availability and low cost. To address this situation, the effects of enzymolysis combined with hydroxypropylation or crosslinking on the structure and hydration properties of OPKEDF were investigated, and the impact of these modified OPKEDFs on the properties of egg white protein gel (EWPG) was studied. Enzymolysis combined with hydroxypropylation or phosphate crosslinking improved the soluble fiber content (5.25-7.79 g/100 g), water-retention and expansion abilities of OPKEDF (p < 0.05). The addition of unmodified OPKEDF or modified OPKEDF increased the random coil content of EWPG and increased the density of its microstructure. Moreover, enzymolysis combined with hydroxypropylation or crosslinking enhanced the effect of OPKEDF on the properties of EWPG, including improvements in its water-retention ability, pH, hardness (from 97.96 to 195.00 g), chewiness (from 78.65 to 147.39 g), and gumminess (from 84.63 to 152.27) and a reduction in its transparency (p < 0.05). Additionally, OPKEDF and enzymolysis and hydroxypropylated OPKEDF increased the resilience (0.297 to 0.359), but OPKEDF treated via enzymolysis and crosslinking reduced it. Therefore, OPKEDF modified by means of enzymolysis in combination with hydroxypropylation or crosslinking improved the gel properties of EWPG. However, further work is required to determine the effects of these modifications on the nutritional profile, scalability, and economic feasibility of OPKEDF and egg white gel.

Effect of κ-carrageenan on the quality of crayfish surimi gels

The demand for crayfish surimi products has grown recently due to its high protein content. This study examined the effects of varying κ-carrageenan (CAR) and crayfish surimi (CSM) concentrations on the gelling properties of CAR-CSM composite gel and its intrinsic formation process. Our findings demonstrated that with the increasing concentration of carrageenan, the quality of CAR-CSM exhibited rising trend followed by subsequently fall. Based on the textural qualities, the highest quality CAR-CSM was achieved at 0.3% carrageenan addition. With the exception of chewiness, and the cooking loss of the gel system was 1.62%, whiteness was 82.35%, and the percentage of β-sheets increased to 57.18%. Further increase in CAR (0.4-0.5%) addition resulted in internal build-up of LCAR-CSM, conversion of intermolecular forces into disulfide bonds and gel breakage. This study exudes timely recommendations for extending the CAR application for the continuous development of crayfish surimi and its derivatives and its overall economic worth.

Effects of nano freezing-thawing on myofibrillar protein of Atlantic salmon fillets: Protein structure and label-free proteomics

This study investigated the impact of magnetic nanoparticles (MNPs) -assisted cryogenic freezing integrated with MNPs combined microwave thawing (NNMT) on the structural integrity of myofibrillar proteins and alterations in protein profiles in salmon fillets. The NNMT showed the lowest myofibrillar fragmentation index (MFI) value (2.73 ± 0.31) among the four freezing-thawing groups. The myofibrillar structure exhibited the highest level of integrity, while the myofibrillar proteins demonstrated minimal aggregation and displayed the most stable secondary and tertiary structures in response to NNMT treatment. Compared with the other three treatments, NNMT exhibited a high abundance of ionic and hydrogen bonds, resulting in stronger interactions between the proteins and water molecules. The label-free proteomics analysis revealed that different freezing-thawing methods primarily affected the cytoskeletal proteins, with collagen and myosin being down-regulated due to degradation caused by cold stress and recrystallization. Additionally, NNMT demonstrated a superior capability in stabilizing salmon cytoskeletal proteins.

Effect of low-frequency alternating magnetic fields on the physicochemical, conformational and rheological properties of myofibrillar protein after iterative freeze-thaw cycles

In this work, the effects of low-frequency alternating magnetic fields (LF-AMF) on the physicochemical, conformational, and functional characteristics of myofibrillar protein (MP) after iterative freeze-thaw (FT) cycles were explored. With the increasing LF-AMF treatment time, the solubility, active sulfhydryl groups, surface hydrophobicity, emulsifiability, and emulsion stability of MP after five FT cycles evidently elevated and then declined, and the peak value was obtained at 3 h. Conversely, the moderate LF-AMF treatment time can significantly reduce the average particle size, carbonyl content, and endogenous fluorescence intensity of MP. The rheology results showed that various LF-AMF treatment times would elevate the G' value of MP after iterative FT cycles. The FTIR spectroscopy results suggested that LF-AMF influenced the secondary structure of MP after multiple FT cycles, resulting in a depression in α-helix content and an increment in β-folding proportion. Moreover, LF-AMF treatment induced the gradually lighter and wider myosin heavy chain bands of MP, implying that LF-AMF accelerated the degradation of macromolecular aggregates. Therefore, the LF-AMF treatment efficaciously ameliorates the structural and functional deterioration of MP after iterative FT cycles and could be used as a potential quality-improving technology in the frozen meat industry.

Cryoprotective Effects of Carrageenan Oligosaccharides on Crayfish (Procambarus clarkii) during Superchilling

Cryoprotectants are widely used to protect muscle tissue from ice crystal damage during the aquatic products freezing process, but traditional phosphate cryoprotectants may cause an imbalance in the calcium-to-phosphorus ratio for the human body. This study evaluated the effects of carrageenan oligosaccharides (CRGO) on quality deterioration and protein hydrolysis of crayfish (Procambarus clarkii) during superchilling. The physical-chemical analyses showed that CRGO treatments could significantly (p < 0.05) inhibit the increase of pH values, TVB-N, total viable counts, and thawing loss, and improve the water holding capacity and the proportion of immobilized water, which indicated that CRGO treatment effectively delayed the quality deterioration of crayfish. The myofibrillar protein structural results demonstrated that the increase of the disulfide bond, carbonyl content, S₀-ANS, and the decrease of total sulfhydryl content were suppressed significantly (p < 0.05) in CRGO treatment groups. Furthermore, SDS-PAGE results showed that the band intensity of myosin heavy chain and actin in CRGO treatment groups were stronger than in the control. Overall, the application of CRGO to crayfish might maintain better quality and stable protein structure during the superchilling process, and CRGO has the potential to replace phosphate as a novel cryoprotectant for aquatic products.

Role of Food Hydrocolloids as Antioxidants along with Modern Processing Techniques on the Surimi Protein Gel Textural Properties, Developments, Limitation and Future Perspectives

Texture is an important parameter in determining the quality characteristics and consumer acceptability of seafood and fish protein-based products. The addition of food-based additives as antioxidants (monosaccharides, oilgosaccharides, polysaccharides and protein hydrolysates) in surimi and other seafood products has become a promising trend at an industrial scale. Improvement in gelling, textural and structural attributes of surimi gel could be attained by inhibiting the oxidative changes, protein denaturation and aggregation with these additives along with new emerging processing techniques. Moreover, the intermolecular crosslinking of surimi gel can be improved with the addition of different food hydrocolloid-based antioxidants in combination with modern processing techniques. The high-pressure processing (HPP) technique with polysaccharides can develop surimi gel with better physicochemical, antioxidative, textural attributes and increase the gel matrix than conventional processing methods. The increase in protein oxidation, denaturation, decline in water holding capacity, gel strength and viscoelastic properties of surimi gel can be substantially improved by microwave (MW) processing. The MW, ultrasonication and ultraviolet (UV) treatments can significantly increase the textural properties (hardness, gumminess and cohesiveness) and improve the antioxidative properties of surimi gel produced by different additives. This study will review potential opportunities and primary areas of future exploration for high-quality surimi gel products. Moreover, it also focuses on the influence of different antioxidants as additives and some new production strategies, such as HPP, ultrasonication, UV and MW and ohmic processing. The effects of additives in combination with different modern processing technologies on surimi gel texture are also compared.