Improvement of the emulsifying properties of Zanthoxylum seed protein by ultrasonic modification

Plant-based whipping cream: A promising sustainable alternative to dairy products

Future food is dedicated to transforming the traditional production model of the food industry, making people and the planet healthier, and addressing the challenges facing humanity. The development of plant-based foods is one of the core contents of future food and an important way to achieve green and low-carbon development of the food industry. A prevailing food trend in the dairy industry is the demand to develop various plant-based alternatives to dairy products. Plant-based whipping cream is a complex emulsion-foam system that can be transformed from an oil-in-water emulsion structure to a triphasic (solid-liquid-gas) foam structure by whipping, which should achieve a subtle balance between emulsion stability, whipping destabilization, and foam re-stabilization. This review aims to understand the science and technology underlying the development of plant-based whipping cream. The initial focus is on the fundamental principle of stabilization and destabilization of plant-based whipping cream, as the development of successful products depends on understanding their physicochemical basis. Three main processing technologies for the manufacture of plant-based whipping cream are then introduced: homogenization, sterilization, and tempering. Besides that, the role of the basic ingredients in plant-based whipping cream is highlighted, including vegetable fats, plant proteins, low-molecular-weight emulsifiers, and thickeners. In order to quantify and compare the quality attributes of different plant-based whipping cream products under standardized conditions, we provide an overview of characterization methods to evaluate emulsion stability, whipping destabilization, and foam re-stabilization of plant-based whipping cream. Subsequently, the legislations and regulations related to plant-based whipping cream products are introduced to cater to their market development. Finally, the current challenges faced by plant-based whipping cream are highlighted. This review aims to provide a guidance for researchers and manufacturers in related industries.

Pickering emulsions stabilized by chitosan-zein-lipase particles for interfacial catalysis

Lipase is widely used in the food industry, but its catalytic efficiency is limited by the insufficient enzyme-substrate contact. To address this issue, chitosan-zein complex particles immobilized lipase (CZPs-lipase) and the corresponding Pickering emulsion catalytic system (PEC) were fabricated. The results showed that the incorporation of zein increased the three-phase contact angle of the particles and decreased the particle size, facilitating lipase immobilization. However, the reduced ζ-potential of the particles was unfavorable for the lipase immobilization by electrostatic adsorption. As a compromise, the maximum immobilized lipase activity was obtained at a chitosan:zein mass ratio of 1:2 (CZPs1:2-lipase). In addition, the PEC stabilized by CZPs-lipase had a significantly (P < 0.05) smaller particle size than that stabilized by chitosan-lipase particles. Consequently, after 120 min of reaction, the hydrolysis rate of p-nitrophenol palmitate in the PEC stabilized by CZPs1:2-lipase was 1.66 and 3.67 times that of the free lipase emulsion and the free lipase biphasic catalytic system, respectively. Meanwhile, after 180 min of reaction, the hydrolysis rate of corn oil and soybean oil in the PEC reached 75.68 ± 1.85 % and 96.27 ± 2.26 %, respectively, significantly (P < 0.05) higher than that in the free lipase emulsion. After five cycles, the relative hydrolysis rate remained at approximately 85 %. This efficient PEC has considerable potential for applications in the food industry.

Impact of ultrasound-assisted extraction on the functional and structural properties, digestibility, hypoglycemic and lipid-lowering effects of seabuckthorn seed meal glutelin

Seabuckthorn seed meal (SSM) is a protein-rich by-product of the oil extraction industry. This study investigated the effects of ultrasound-assisted extraction (UAE) on the physicochemical and functional properties, in vitro digestibility, as well as hypoglycemic and lipid-lowering activities of SSM glutelin. Results indicated that SSM glutelin extracted with UAE (USBG) exhibited higher extraction yield and protein content than SSM glutelin extracted without ultrasound (SBG). Additionally, UAE increased amino acid content, loosened the protein structure, reduced particle size, altered the secondary and tertiary structures of USBG. Moreover, USBG demonstrated enhanced functional properties, like solubility, water-holding and oil-holding capacity, thermal stability, and so on. UAE also improved the in vitro digestibility of USBG, while decreasing the particle size and increasing amino content after digestion. Furthermore, USBG exhibited enhanced hypoglycemic and lipid-lowering activities. Therefore, UAE significantly improves the structure, functionality, digestibility and bioactivities of SSM glutelin, thereby adding value to seabuckthorn by-products.

Synergistic Effects of Ultrasound and pH-Shifting on the Solubility and Emulsification Properties of Peanut Protein

Peanut protein is a byproduct of peanut oil extraction with limited applications within the food sector due to its low solubility and emulsifying properties. This study investigated the influences and mechanisms of high-intensity ultrasound (HIU, 200~600 W) and pH-shifting (pH 12), either individually or jointly, on the structure, solubility, and emulsifying properties of PP. Results indicated that the solubility of PP significantly increased after the combined treatment, particularly when the HIU power was 300 W (p < 0.05). Accordingly, emulsions prepared from it exhibited highest storage stability. Structural analysis indicated that the increased PP solubility (9.95% to 54.37%, p < 0.05) is mainly attributed to the structural changes that occur during protein unfolding, resulting in the uncovering of hydrophobic groups (7181.43 to 14,083.00, p < 0.05) and the reduction of α-helices (24.43% to 18.17%, p < 0.05). Moreover, confocal laser scanning microscopy of the emulsions revealed that the combination-treated PP resulted in smaller protein particle sizes (50.09 μm to 15.68 μm, p < 0.05), tighter adsorption on the oil-water interface, and a denser and more stable interfacial film compared to the native and the individual treatment, thereby enhancing the stability of the system. A rheological analysis confirmed that the combined treatment improved the interfacial properties of the protein, which was advantageous for emulsion stability. In conclusion, HIU combined with pH12-shifting can appreciably improve the solubility and emulsifying properties of PP to broaden its application prospects.

Effects of ultrasound treatment on structural and functional properties of radish seed protein

Dried radish seed is a traditional Chinese herbal medicine that is rich in oil and protein. Radish seed meal, which is a byproduct of oil production, is high in protein (30%-35%). In order to develop a novel plant protein with excellent functional properties, this study investigated the effects of ultrasound treatment (20 kHz, amplitude of 40%, 0-10 min) on the physicochemical, functional, and antioxidant properties of radish seed protein (RSP) extracted from radish seed meal. The molecular weight of RSPs was 11-75 kDa. Ultrasonic treatments at 2-10 min reduced the particle size, narrowed the size distribution, and increased the surface negative charge of RSP. RSP solubility increased from 77.69% ± 0.69% to 88.50% ± 1.36% after ultrasound treatment for 10 min, resulting in optimal foaming and emulsifying properties of RSP. However, the foam stability of RSP decreased after sonication for 10 min. By contrast, the antioxidant activities of RSP increased significantly with extended sonication duration. Although sodium dodecyl sulfate-polyacrylamide gel electrophoresis results showed that sonication had few effects on RSP digestibility, the antioxidant capacities of the digested products during simulated intestinal digestion were enhanced, indicating RSP to be a good resource of antioxidant peptides. These results provide a fundamental basis for the use of ultrasound to enhance the functional and antioxidant abilities of RSP, promoting its application in food industry and the bioactive peptide field.

Ultrasonic combined pH shifting strategy for improving the stability of emulsion stabilized by yeast proteins: Focused on solubility, protein structure, interface properties

In this study, the improvement mechanism of yeast proteins (YPs) with the ultrasonic and pH shifting treatment on the emulsion stability was investigated through the solubility, protein structure and interface behavior of YPs. Compared with only pH shifting or ultrasound treatment, the solubility of YPs with the combined treatment of ultrasonic and pH shifting was increased significantly. The soluble protein content of pH-U400 reached 85.51 %. The results of YPs structure demonstrated that the β-sheet, α-helix and disulfide bonds contents of YPs with the combined treatment first declined and subsequently increased with increasing ultrasonic power, under alkaline conditions. The fluorescence intensity and surface hydrophobicity first increased and then declined. The more flexible protein structure endowed pH-U400 with lower interfacial tension, higher interfacial diffusion, penetration and reorganization rate, and interfacial protein concentration. The pH-U400 showed the best emulsifying properties (emulsifying activity index was 27.05 m2/g, emulsifying stability index was 31.27 min) and could prepare smaller and more uniform emulsion droplet. The results of multiple light scattering demonstrated that emulsion stabilized by pH-U400 showed the best stability. These results revealed the stability mechanism of emulsions stabilized by YPs and provided guidance for further development of practical YPs products in the food industry.

Pickering emulsions stabilized by ultrasound-assisted phosphorylated cantaloupe seed protein isolate -chitosan: Preparation, characterization and stability

Cantaloupe seed protein isolate (CSPI) has attracted the attention of its low cost, easy digestion and balanced composition of essential amino acids. However, due to the low solubility of CSPI, its application in the food industry is limited. Therefore, the present study investigated the effect of ultrasound-assisted phosphorylation on the solubility of CSPI and the structural properties were characterized. The solubility of cantaloupe seed protein increased from 9.17 % to 63.27 % by ultrasound assisted phosphorylation, and resulting in an increase in the absolute value of CSPI potential, a decrease in particle size, and a stable structure, which could be used for the construction of the food emulsification system. The modified CSPI was combined with chitosan (CS) to prepare stabilized Pickering emulsion for subsequent stability study. The results showed that stable Pickering emulsions could be prepared with CSPI at pH 7, CS 0.5 % and oil phase fraction 55 %. Ultrasound-assisted phosphorylation enhanced electrostatic interaction between CS's -NH3 groups and CSPI's -COO-groups which improved the storability of stabilized Pickering emulsion. This will help to broaden the application range of CSPI and provide a theoretical basis for CPI stable Pickering emulsion.

Physicochemical, techno-functional, biochemical and structural characterization of a protein isolate from groundnut (Arachis hypogaea L.) paste treated with high-intensity ultrasound

The objective of this research was to evaluate the effect of ultrasound (HISound) (200, 400 and 600 W; 15-30 min) on the physicochemical, biochemical and structural techno-functional properties of a groundnut paste protein isolate (GPPI). HISound increased the contents of free sulfhydryls (552.22 %), total sulfhydryls (124.68 %) and α-helix (389.75 %), as well as molecular flexibility (50.91 %), hydrophobic surface (38.99 %), and particle size (171.45 %) of GPPI, which improved protein solubility by 8.05 %, oil holding capacity by 73.54 %, emulsifying stability index by 226.25 % and foaming capacity by 216.00 %, compared with non-sonicated GPPI. Also, the microstructure analysis revealed smooth structures, with molecular weights in the range of 13.88-67.07 kDa. Pearson analysis determined some highly significant correlations (r ≥ 0.90, p < 0.01) between some GPPI protein properties. The improvement of GPPI properties by HISound could contribute to its use as an ingredient for human consumption.

Modification of pepper seed protein isolate to improve its functional characteristic by high hydrostatic pressure

Pepper seed protein isolate (PSPI) is a valuable plant-based protein source, yet the impact of processing methods such as high hydrostatic pressure (HHP) on its properties remains unclear. The impact of HHP on the structural and functional properties of PSPI at pH 7 and pH 9 was evaluated. Structural changes in PSPI were analyzed using spectral techniques, revealing significant alterations in the secondary and tertiary structures induced by HHP treatment. HHP treatment caused the unfolding of the PSPI structure, leading to the exposure of previously hidden chromophores and hydrophobic groups. The treatment also led to changes in free sulfhydryl groups and increased average particle size suggesting the formation of macromolecular polymers or insoluble aggregates. Consequently, the water-holding capacity, oil-holding capacity, foaming characteristics, and emulsifying activity index of the modified PSPI were significantly enhanced both at pH 7 and pH 9, with maximum improvements of 121.98 %, 157.29 %, 100.00 %, and 265.78 %, respectively. In conclusion, HHP is a promising strategy for enhancing the physicochemical properties of PSPI for various applications.

Modification approaches of walnut proteins to improve their structural and functional properties: A review

Walnut protein has a high gluten content and compact structure, which limits its water solubility and affects its applications. Therefore, improving the sustainability of walnut proteins is an urgent issue that must be addressed. Physical modification can directly alter the structure of walnut proteins, leading to enhanced functional properties. Chemical modifications typically involve the introduction of exogenous substances that react with walnut proteins to obtain novel products with improved processing attributes. As a highly specific modification technique, biomodification uses enzymes or microorganisms to break down walnut proteins into small peptide molecules or cross-link them to form soluble polymers, thereby enhancing their functional properties and bioactivity. This review presents various methods for modifying walnut proteins and their effects on the structure and functional properties of walnut proteins. The challenges associated with the application and development of these unique technologies are also discussed.

Unveiling the transformative influence of sonochemistry on formation of whey protein isolate and green tea extract (WPI-GTE) conjugates

This study investigated the formation of conjugates between whey protein isolate (WPI) and green tea extract (GTE) using three methods: redox-pair (R), ultrasound-assisted redox-pair (RU), and ultrasonication (UL). Ultrasonication significantly reduced the reaction time for synthesizing WPI-GTE conjugates compared to the standard R method (p < 0.05). The UL methods had the highest conjugate yield determined by polyphenol binding (p < 0.05). Fourier-transform infrared spectroscopy (FTIR) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) confirmed the conjugate formation, indicating an increased molecular weight due to protein binding with polyphenols through covalent and non-covalent bonds. Conjugates produced via ultrasonication exhibited enhanced solubility, smaller particle size, better emulsifying capacity, and improved foaming ability compared to those formed using the traditional R method (p < 0.05). However, conjugates from the R method showed higher antioxidant activity, as evidenced by DPPH•and ABTS•+ scavenging activities (p < 0.05). In conclusion, WPI-GTE conjugates created through ultrasonic treatment demonstrate potential as dual-functional ingredients, serving as both antioxidant and emulsifier.

Effects of ultrasonic treatment on the structure and functional characteristics of myofibrillar proteins from black soldier fly

In the process of utilizing black soldier fly larvae (BSFL) lipids to develop biodiesel, many by-products will be produced, especially the underutilized protein components. These proteins can be recycled through appropriate treatment and technology, such as the preparation of feed, biofertilizers or other kinds of bio-products, so as to achieve the efficient use of resources and reduce the generation of waste. Myofibrillar protein (MP), as the most important component of protein, is highly susceptible to environmental influences, leading to oxidation and deterioration, which ultimately affects the overall performance of the protein and product quality. For it to be high-quality and fully exploited, in this study, black soldier fly myofibrillar protein (BMP) was extracted and primarily subjected to ultrasonic treatment to investigate the impact of varying ultrasonic powers (300, 500, 700, 900 W) on the structure and functional properties of BMP. The results indicated that as ultrasonic power increased, the sulfhydryl content and turbidity of BMP decreased, leading to a notable improvement in the stability of the protein emulsion system. SEM images corroborated the changes in the microstructure of BMP. Moreover, the enhancement of ultrasound power induced modifications in the intrinsic fluorescence spectra and FTIR spectra of BMP. Additionally, ultrasonic treatment resulted in an increase in carbonyl content and emulsifying activity of BMP, with both peaking at 500 W. It was noteworthy that BMP treated with ultrasound exhibited stronger digestibility compared to the untreated. In summary, 500 W was determined as the optimal ultrasound parameter for this study. Overall, ultrasound modification of insect MPs emerges as a dependable technique capable of altering the structure and functionality of BMP.

High Internal Phase Emulsions Stabilized with Ultrasound-Modified Spirulina Protein for Curcumin Delivery

Spirulina protein (SP) is recognized as a nutritious edible microbial protein and holds potential as a natural emulsifier. Due to the inherent challenges SP faces in stabilizing high internal phase emulsions (HIPEs), ultrasonic techniques were utilized for modification. Noticeable alterations in the structural and functional properties of SP were observed following ultrasonic treatment at various power levels (0, 100, 300, and 500 W). Ultrasound treatment disrupted non-covalent interactions within the protein polymer structure, leading to the unfolding of molecular structures and the exposure of hydrophobic groups. Importantly, the particle size of SP was reduced the most at an ultrasonic power of 300 W, and the three-phase contact angle reached its peak at 84.3°. The HIPEs stabilized by SP modified with 300 W ultrasonication have high apparent viscosity and modulus values and strong storage stability under different environmental conditions. Additionally, the encapsulation of curcumin in HIPEs led to improved retention of curcumin across various settings. The bioavailability increased to 35.36, which is 2.8 times higher than the pure oil. These findings suggest that ultrasound-modified SP is a promising emulsifier for HIPEs, and is expected to encapsulate hydrophobic nutrients such as curcumin more effectively.

The Preparation and Characterization of Quinoa Protein Gels and Application in Eggless Bread

The properties of xanthan gum protein gels composed of quinoa protein (XG-QPG) and ultrasound-treated quinoa protein (XG-UQPG) were compared for the preparation of high-quality quinoa protein gels. The gel qualities at different pH values were compared. The gels were used to produce eggless bread. Microscopically, the secondary structure of the proteins in XG-QPG (pH 7.0) was mainly α-helix, followed by random coiling. In contrast, the content of β-sheet in XG-UQPG was higher, relative to the viscoelastic properties of the gel. Moreover, the free sulfhydryl groups and disulfide bonds of XG-QPG (pH 7.0) were 48.30 and 38.17 µmol/g, while XG-UQPG (pH 7.0) was 31.95 and 61.58 µmol/g, respectively. A high disulfide bond content was related to the formation of gel networks. From a macroscopic perspective, XG-QPG (pH 7.0) exhibited different pore sizes, XG-UQPG (pH 7.0) displayed a loose structure with uniform pores, and XG-UQPG (pH 4.5) exhibited a dense structure with small pores. These findings suggest that ultrasound can promote the formation of a gel by XG-UQPG (pH 7.0) that has a loose structure and high water-holding capacity and that XG-UQPG (pH 4.5) forms a gel with a dense structure and pronounced hardness. Furthermore, the addition of the disulfide bond-rich XG-UQPG (pH 7.0) to bread promoted the formation of gel networks, resulting in elastic, soft bread. In contrast, XG-UQPG (pH 4.5) resulted in firm bread. These findings broaden the applications of quinoa in food and provide a good egg substitute for quinoa protein gels.

Characteristics of Quinoa Protein Isolate Treated by Pulsed Electric Field

The aim of this study was to investigate the impact of a pulsed electric field (PEF) on the structural and functional properties of quinoa protein isolate (QPI). The findings revealed a significant alteration in the secondary structure of QPI following PEF treatment, converting the random coil into the β-sheet, resulting in an improvement in structure orderliness and an enhancement of thermal stability. The PEF treatment led to a reduction in particle size, induced structural unfolding, and increased the surface hydrophobicity, resulting in a statistically significant enhancement in the solubility, foaming, and emulsifying properties of QPI (p < 0.05). Specifically, PEF treatment at 7.5 kV/cm for 30 pulses was identified as the optimal condition for modifying QPI. This study provides a basis for the precision and range of application of pulsed electric field treatment and offers the possibility of improving the physical and chemical properties of quinoa protein.