High-pressure homogenization influences the functional properties of protein from oyster (Crassostrea gigas)

Structural, properties and digestion in vitro changes of starch subjected to high pressure homogenization: An update review

High pressure homogenization (HPH) is considered as a promising method for improving the ideal metabolic reaction of starch-based foods in the body, but there is still no comprehensive understanding of the structure-property relationship of starch treated with HPH. This study reviews the advantages and limitations of HPH in starch-based foods processing in recent years. It also elaborates the bidirectional regulation of HPH on starch structure-property and its potential in improving nutritional quality, which includes the regular modification effects of HPH on the multi-scale structure, physicochemical properties, and digestion characteristics of starch. It was found that HPH could lead to the degradation of amylopectin, destruction of amorphous structure, and homogenization of fine particles, promoting gelatinization and ultimately endowing starch with good solubility and digestibility. Moreover, it could reorganize and reorder the internal starch chains, or cause the particles to disintegrate into an amorphous state, thereby enhancing the anti-digestibility of starch. The interaction of starch with different nutrients during the HPH process could be further investigated in future studies and explored with other techniques for structure-property modifications, which would help expand the development of personalized starch foods to meet growing consumer demands.

Effect of ultrasound-assisted Maillard reaction on functional properties and flavor characteristics of Oyster protein enzymatic hydrolysates

To address the delamination phenomenon during storage and flavor characteristics of Oyster protein hydrolysates (OPH). In this study, xylo-oligosaccharides (XOS) were selected to covalently graft with OPH through ultrasound-assisted Maillard reaction, and the effect of ultrasound-assisted Maillard reaction on the structure, functional properties, and flavor characteristics of OPH were investigated. The results revealed that the ultrasound treatment led to a 1.46-fold increase in the degree of grafting compared with the conventional wet-heat Maillard reaction methods. Structural analyses at various levels indicated substantial alterations in the OPH structure following the ultrasound-assisted Maillard reaction. More ordered α-helical secondary structures were shifting to random coiling, the tertiary structure showed more stretching changes, and the surface structure was characterized by loose and porous features. Compared with OPH, the solubility of the ultrasound-assisted Maillard reaction products (OPH-U-M) increased from 54.67% to 70.14%, leading to a notable enhancement in storage stability. Flavor profile analysis demonstrated a decrease in unsaturated aldehydes and ketones presenting fishy and bitter aromas, while an increase in presenting meat aroma compounds was observed in OPH-U-M. Furthermore, OPH-U-M exhibited superior antioxidant properties with DPPH and ABTS radical scavenging abilities enhancing 46.05% and 42.09% in comparison with OPH, respectively. The results demonstrated that covalently binding with XOS under ultrasonication pretreatment endowed OPH with superior functional properties (including solubility, storage stability, and antioxidant activity), and the improvement of flavor profile. This study can provide theoretical guidance and practical implications for promoting the processing applications of oyster protein.

Molecular structural modification of myofibrillar protein from oyster (Crassostrea gigas) with oligosaccharides for improving its gel properties

Glycation is a promising approach to enhance protein gel characteristics in the food industry. The impact of oyster myofibrillar protein (MP) being glycosylated with six oligosaccharides (dextran [Dex]-1 kDa, 5 kDa, 6 kDa, and 10 kDa, xylan [Xyla], and xyloglucan [Xyg]) on structural properties, aggregation behavior and gel properties was investigated in this study. The findings demonstrated that oligosaccharides significantly increased the glycation degree of MP by forming a stable tertiary conformation, increasing the contents of the disulfide bond and hydrogen bonds. Additionally, particle sizes decreased and solubility increased after glycation, improving the gel's strength, water-holding capacity, thermal stability, elastic modulus, and ordered network layout. It was determined that MP-Dex 5 had the best gel properties. The gel strength and water holding capacity of MP-Dex 5 increased by 70.59% and 32.27%, respectively. Molecular dynamics simulations results showed van der Waals energy and electrostatic interactions favor myosin binding to Dex or Xyla units. This study will provide insights into the relationship between molecular structure, aggregation behavior and gel property of oyster MP-oligosaccharide couples, and expand the application of oyster MP in food gels.

Blue food proteins: Novel extraction technologies, properties, bioactivities and applications in foods

With the growing demand for healthy and sustainable food, blue food proteins have emerged as an important way to address resource-intensive production and environmental concerns. This paper systematically reviewed the extraction technologies, properties and bioactivities of blue food proteins and explored their wide range of applications. The novel extraction technologies not only improve the extraction efficiency of the proteins, shorten the production time and have environmental advantages, but also enhance the protein properties and facilitate subsequent applications. The amino acid composition of the blue food proteins is close to the FAO recommended standard and better than most of the livestock proteins, with excellent solubility and water holding capacity. Some of the proteins also have significant bioactivity and show great potential for improving health. Applications include emulsions, protein films, microcapsules, food colorants, dietary supplements, 3D printing materials, and cultured meat. This paper provides theoretical support for further research and application of blue food proteins and promotes their wider application in future food products.

Effects of High-Pressure Homogenization on the Structure and Functional Properties of Solenaia oleivora Proteins

Solenaia oleivora, a rare freshwater shellfish with high protein quality, is unique to China. However, the poor hydrosolubility and functional properties of Solenaia oleivora proteins hinder their utilization in food products. Herein, the alkaline dissolution-isoelectric precipitation method was used for the extraction of Solenaia oleivora proteins. Furthermore, the impact of high-pressure homogenization (HPH) treatment varying from 0 to 100 MPa on the structure and functional properties of Solenaia oleivora proteins was investigated. The obtained results indicated that HPH treatment decreased the α-helix content and enhanced the β-sheet and random coil content. Furthermore, the HPH caused the unfolding of protein structure, exposing aromatic amino acids, increasing the free thiol group content, and enhancing surface hydrophobicity. As the homogenization pressure increased from 0 to 100 MPa, the particle size of Solenaia oleivora proteins decreased from 899 to 197 nm with the polymer dispersity index (PDI) value decreased from 0.418 to 0.151, the ζ-potential increased from -22.82 to -43.26 mV, and the solubility increased from 9.54% to 89.96%. Owing to the significant changes in protein structure and solubility, the emulsifying, foaming, and digestive properties of Solenaia oleivora proteins have been significantly improved after treatment with HPH.

Influence of heat treatment before and/or after high-pressure homogenization on the structure and emulsification properties of soybean protein isolate

This study investigates the effects of heat treatment before high-pressure homogenization (HHPH) and heat treatment after high-pressure homogenization (HPHH) at different pressures (20, 60, and 100 MPa) on the structural and emulsification properties of soy protein isolate (SPI). The results indicate that HHPH treatment increases the surface hydrophobicity (H0) of the SPI, reduces β-fold and irregular curls, leading to the formation of soluble aggregates, increased adsorbed protein content, and subsequent improvements in emulsification activity index (EAI) and emulsion stability index (ESI). In contrast, the HPHH treatment promoted the exchange of SH/SS bonds between protein molecules and facilitated the interaction of basic peptides and β-subunits, leading to larger particle sizes of the soluble aggregates compared to the HHPH-treated samples. However, excessive aggregation in HPHH-treated aggregates leads to decreased H0 and adsorbed protein content, and increased interfacial tension, negatively affecting the emulsification properties. Compared to the HPHH treatment, HHPH treatment at homogenization pressures of 20 to 100 MPa increases EAI and ESI by 5.81-29.6 % and 5.31-25.9 %, respectively. These findings provide a fundamental basis for soybean protein manufacturers to employ appropriate processing procedures aimed at improving emulsification properties.

Modifications to structural, techno-functional and rheological properties of sesame protein isolate by high pressure homogenization

In this study, we aimed to determine the effect of high pressure homogenization (HPH) at a pressure up to 150 MPa on microstructural, techno-functional and rheological properties of sesame protein isolate (SPI). HPH treatment caused a partial change in the secondary structure of SPI, however, the changes in surface hydrophobicity and free -SH groups, indicating HPH had significant effect on the tertiary structure. After the HPH treatment, the particles dispersed homogeneously with more rougher surface. Sesame proteins had the smallest particle size (0.79 μm) and highest zeta potential (38.83 mV) at 100 MPa pressure. The most developed water/oil holding capacity, emulsification and foaming properties were achieved at 100 MPa pressure. However, the maximum stable foam formation (83.33 %) was determined at 150 MPa pressure. When the shear rate is fixed as 50 1/s, an increase in the viscosity value of the samples treated with 100 and 150 MPa pressure was detected compared to the control sample, while the lowest viscosity was determined the ones treated at 50 MPa. In all samples except 50 MPa pressure-treated proteins, viscoelastic character became dominant with increasing frequency (G' > G″). Modification with HPH resulted in a decrease of about 15 °C in the gelation temperature of SPI.

Effects of high-pressure homogenization on the physicochemical, foaming, and emulsifying properties of chickpea protein

In order to expand the utilization of chickpeas in various food products, this study investigated the effects of different homogenization pressures (0-150 MPa) and cycles (1-3) on the physicochemical, and functional properties of chickpea protein. After high-pressure homogenization (HPH) treatment, hydrophobic groups and sulfhydryl groups of chickpea protein was exposed which increased its surface hydrophobicity and decreased its total sulfhydryl content. SDS-PAGE analysis showed that the molecular weight of modified chickpea protein remained unchanged. The particle size and turbidity of chickpea protein significantly decreased with an increase in homogenization pressure and cycles. Furthermore, the solubility, foaming, and emulsifying properties of chickpea protein were all enhanced by HPH treatment. In addition, the emulsions prepared by modified chickpea protein showed better stability capacity due to its smaller particle size and higher zeta potential. Therefore, HPH might be an effective technique to improve the functional properties of chickpea protein.

Effect of sodium trimetaphosphate on the physicochemical properties of modified soy protein isolates and its lutein-loaded emulsion

Due to people's pursuit of healthy and green life, soy protein isolate (SPI) is occupying a larger and larger market share. However, the low solubility of SPI affects its development in the field of food and medicine. This paper aimed to investigate the effects of sodium trimetaphosphate (STMP) on the functional properties and structures of phosphorylated SPI and its lutein-loaded emulsion. After modification by STMP, the phosphorus content of phosphorylated SPI reached 1.2-3.61 mg/g. Infrared spectrum and X-ray photoelectron spectrum analysis confirmed that PO₄ ^3- had phosphorylation with -OH in serine of SPI molecule. X-ray diffraction analysis showed that phosphorylation destroyed the crystal structure of protein molecules. Zeta potential value of phosphorylated SPI decreased significantly. When STMP addition was 100 g/kg, particle size of protein solution decreased to 203 nm, and solubility increased to 73.5%. Furthermore, emulsifying activity and emulsifying stability increased by 0.51 times and 8 times, respectively. At the same protein concentration (1%-3% [w/w]), lutein-loaded emulsion prepared by phosphorylated SPI had higher absolute potential and smaller particle size. The phosphorylated protein emulsion at 2% concentration had the best emulsion stability after storage for 17 days. PRACTICAL APPLICATION: Phosphorylation significantly improved the emulsifying properties and solubility of SPI. Phosphorylated SPI significantly improved the stability of lutein-loaded emulsion. It provides theoretical basis for the application of phosphorylated SPI as emulsifier in delivery system and broadens the development of lutein in food and medicine field.

Structural Characteristics and Emulsifying Properties of Soy Protein Isolate Glycated with Galacto-Oligosaccharides under High-Pressure Homogenization

This study explored the Maillard reaction process during the glycation of soy protein isolate (SPI) with galacto-oligosaccharides (GOSs) under high-pressure homogenization (HPH) and its effects on the emulsifying properties of SPI. SPI-GOS glycation under moderate pressure (80 MPa) significantly inhibited the occurrence and extent of the Maillard reaction (p < 0.05), but homogenization pressures in the range of 80−140 MPa gradually promoted this reaction. HPH caused a decrease in the surface hydrophobicity of the glycated protein, an increase in the abundance of free sulfhydryl groups, unfolding of the protein molecular structure, and the formation of new covalent bonds (C=O, C=N). Additionally, the particle size of emulsions created with SPI-GOS conjugates was reduced under HPH, thus improving the emulsifying properties of SPI. A reduction in particle size (117 nm), enhanced zeta potential (−23 mV), and uniform droplet size were observed for the emulsion created with the SPI-GOS conjugate prepared at 120 MPa. The conformational changes in the glycated protein supported the improved emulsification function. All results were significantly different (p < 0.05). The study findings indicate that HPH provides a potential method for controlling glycation and improving the emulsifying properties of SPI.

Thoroughly review the recent progresses in improving O/W interfacial properties of proteins through various strategies

Along with the future food market developing world widely, the personalized nutrition and rational function food design are found to be urgently attracted. Oil in a water (O/W) emulsion system has an excellent ability to maintain nutraceuticals and thus plays a promising role in producing future functional foods. Understanding the interfacial related mechanisms involved are essential for improving the quality of food products. Protein can effectively reduce interfacial tension and stable immiscible phases. The interfacial properties of proteins directly affect the emulsion qualities, which have gradually become a prospective topic. This review will first briefly discuss the interfacial-related fundamental factors of proteins. Next, the paper thoroughly overviewed current physical and chemical strategies tailored to improving the interfacial and emulsion properties of proteins. To be summarized, a higher flexibility could allow protein to be more easily unfolded and adsorbed onto the interface but could also possibly form a softer interfacial film. Several physical strategies, such as thermal, ultrasound and especially high-pressure homogenization are well applied to improve the interfacial properties. The interfacial behavior is also altered by various green chemical strategies, such as pH adjustment, covalent modification, and low molecular weight (LMW) surfactant addition. These strategies upgraded emulsion properties by increasing adsorption load, accelerating diffusion and adsorption rate, associated with lowering interfacial tension, and promoting interfacial protein interactions. Future researches targeted at elucidating interfacial-bulk protein interactions, unraveling interfacial behavior through in silico tools, exploring connection between interfacial-industrial processing properties, and clarifying the interfacial-sensory-digestive relationships of O/W emulsions is needed to develop emulsion applications.

The Spatial Distribution Patterns, Physicochemical Properties, and Structural Characterization of Proteins in Oysters (Crassostrea hongkongensis)

Protein content, a vital component determining the nutritional quality of oysters, is unevenly distributed in different parts of oyster. In this study, the spatial distribution (visceral mass, mantle, gill, and adductor) patterns and structural characteristics of proteins, including water–soluble proteins (WSP), salt–soluble proteins (SSP), acid–soluble proteins (ASP) and alkali–soluble proteins (ALSP) of oysters (Crassostrea hongkongensis) were investigated with the amino acid analyzer, circular dichroism spectroscopy (CD), fourier transform infrared spectroscopy (FTIR), and fluorescence spectroscopy. The results showed that oyster proteins were mainly distributed in the visceral mass and mantle. The protein composition was WSP, SSP, ALSP, and ASP in descending order, which conformed to the ideal amino acid pattern. Variations in secondary structure, molecular weight distribution, and thermal denaturation temperatures of the oyster proteins were observed. SSP had wider bands (16–270 kDa) than those of ASP (30–37 kDa) and ALSP (66–270 kDa). Among the four proteins, the SSP of the mantle showed the highest thermal stability (87.4 °C), while ALSP of the adductor muscle had the lowest the lowest the peak denaturation temperature (Tm) (53.8 °C). The proportions of secondary structures in oyster proteins were different, with a higher proportion of solid protein β–folds, and the exposure of aromatic amino acid residues and disulfide bonds and the microenvironment in which they were located were also different.