Aug 2026· Food Chemistry· Vol 526, pp.
150756
· 0 citations· 25 references
Medicine
TL;DR
Multivariate analysis indicated β-turn content, surface hydrophobicity, and reactive-group content were positively associated with selected functional properties that support ASAP as a promising route, while validation across additional raw materials remains necessary.
Abstract
Limited redispersibility constrains commercial yeast-protein ingredients. This study compared preparation efficiency, structure, and function of yeast protein prepared by alkaline extraction-acid precipitation (ASAP) and high-pressure homogenization-assisted pH shift (HPHS). ASAP achieved higher product yield (69.23% ± 1.42%) and protein recovery (57.81% ± 2.42%) than HPHS. ASAP-YP exhibited dense sheet-like morphology, higher β-turn content (55.71%), and preserved reactive groups, whereas HPHS-YP formed porous aggregates with higher α-helix content and lower sulfhydryl availability. Under tested conditions, ASAP-YP showed higher solubility (pH 3-13), water absorption (17.99 ± 0.62 g/g), oil absorption (7.98 ± 0.12 g/g), emulsifying activity (59.88 ± 2.58 m2/g), and foaming capacity (124.00% ± 2.00%). Multivariate analysis indicated β-turn content, surface hydrophobicity, and reactive-group content were positively associated with selected functional properties. These findings support ASAP as a promising route, while validation across additional raw materials remains necessary.
Yeast protein (YP) is recognized as a sustainable and hypoallergenic microbial protein source, yet its low solubility (typically <22%) severely restricts its utilization in food formulations. Improving solubility is therefore a key step toward broader industrial application of YP. This study investigated a synergistic treatment combining high-pressure homogenization and restriction enzymatic hydrolysis (HPH-neu) to improve the solubility of yeast protein (YP). The HPH-neu treatment significantly enhanced solubility to 81.58 ± 0.29%. In contrast, the individual application of either high-pressure homogenization (HPH) or restriction enzymatic hydrolysis (neu) was less effective in improving solubility than the combined approach. Structural analysis indicated that HPH-neu processing notably increased the contents of α-helix and random coil, and scanning electron microscopy (SEM) revealed a corresponding looser and more disordered microstructure. Furthermore, the combined treatment significantly reduced particle size (242.8 ± 5.59 nm), free sulfhydryl group content (2.20 ± 0.01 μ mol/g), and surface hydrophobicity (H0, 14123.67 ± 257.85).At the same time, it improved functional properties including the emulsifying activity index (40.51 ± 2.86 m2/g), foaming capacity (146.67 ± 2.89%), and in vitro digestibility (90.64 ± 0.33%). The HPH-neu process also yielded high scores for PDCAAS and SRC, reaching 65.96 and 73.11, respectively. In summary, the integrated HPH-neu strategy not only effectively enhanced the solubility of YP but also improved its multifaceted functional properties and digestibility. This strategy offers a promising route for protein valorization and the development of high-quality, nutritious protein ingredients.
Zhaowei Han, Bingyu Chen, Xinxin Li et al.· Food Research International· 1 citation
In the present study, native pumpkin peel protein (PPP) was extracted using alkaline solubilization followed by isoelectric precipitation, yielding 61.3% protein. To enhance its functionality, PPP was chemically modified via succinylation using a 4:1 M ratio of succinic anhydride to lysine residues under controlled alkaline conditions. Structural modifications in succinylated pumpkin protein (MPPP) were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and particle-size and zeta-potential analyses. Functional properties, including solubility, water- and oil-holding capacities, emulsifying behavior, and foaming characteristics, were evaluated, along with antioxidant activity and in vitro digestibility. Succinylation significantly improved protein functionality, with increased solubility (65.66%), water-holding capacity (5.04 g/100 g), oil-holding capacity (2.54 g/100 g), and emulsifying capacity (34.10%). The zeta potential shifted from -5.5 mV to -24.1 mV, indicating enhanced electrostatic stability, accompanied by a reduction in particle size. FTIR confirmed the incorporation of succinyl groups, while SEM and XRD revealed structural loosening and increased amorphous character. Amino acid profiling showed a marked reduction in lysine content, confirming targeted modification. Improved antioxidant activity and enhanced in vitro digestibility further demonstrated the biological relevance of the modified protein. Importantly, this study establishes a matrix-specific mechanism in which succinylation disrupts protein-polysaccharide-phenolic interactions unique to pumpkin peel, leading to enhanced functional performance. These findings highlight the potential of succinylation as an effective strategy for valorizing pumpkin peel into a functional ingredient suitable for applications in food and nutraceutical systems.
Kusum Juneja, Aarti Bains, R. Nagraik et al.· International Journal of Bio...· 0 citations
Structural and functional modifications of common bean (Phaseolus vulgaris L.) protein were investigated using cold atmospheric plasma (CAP) and Maillard reaction (MR) with pectin. CAP treatment (20 kV, 1–5 min) significantly enhanced protein solubility and emulsifying activity. Conversely, MR (90 °C, 0.5–3 h) reduced solubility and foaming properties but improved gelling capacity, achieving the lowest gelation concentration (LGC) at 2–3 h of heating. Conformational shifts in secondary structures (α-helix, β-turn, and β-sheet) were confirmed by FTIR and correlated with protein unfolding and structural modifications, as characterized by SDS-PAGE. Zeta potential measurements indicated that CAP improved colloidal stability, whereas extended MR heating decreased stability. These findings demonstrate that CAP is an effective nonthermal tool for enhancing protein functionality, while MR is better suited for developing stable gel-based food matrices, lowering the LGC from 8% to 5%.
Rukiye Gundogan, T. Dissanayake, A. C. Karaça et al.· ACS Food Science & Techn...· 0 citations
The textural properties of food colloidal systems are highly dependent on the gelling characteristics of animal-derived proteins (such as egg protein, EP) and polysaccharides (such as starch, pectin, and gums). The development of plant-based protein alternatives faces challenges such as insufficient gel strength and poor structural stability. This study focused on purified Chlorella protein extract (PCPE). To address the insufficient gel performance of PCPE, a synergistic optimization strategy of "modification combined with calcium ion regulation" was proposed. Results revealed that alkali treatment strengthened ionic interactions while weakening hydrogen bonds and hydrophobic interactions, promoting protein molecular rearrangement and resulting in a narrower and more concentrated particle-size distribution. This increased the initial storage modulus to 136 Pa, comparable to that of EP. TGase treatment catalyzed protein-protein and protein-polysaccharide covalent cross-linking, forming a dense network structure and significantly increasing gel hardness to approximately 1.5 times that of EP. Furthermore, the addition of calcium ions synergistically enhanced gel strength via salt bridge formation, further elevating the initial storage modulus to 297 Pa. However, a high calcium concentration (25 mM) led to an approximately 20% reduction in water-holding capacity for TGase-treated PCPE gels. This study elucidates the multidimensional regulatory mechanisms underlying enhanced plant-protein gelation and provides a strategy for developing sustainable plant-based gelled foods.
Hao Chen, Qun Gao, Ruoyu Wu et al.· International Journal of Bio...· 0 citations
To valorize Pleurotus eryngii mycelium protein (PeMP) as a sustainable protein source, this study investigated the efficacy of ultrasound-assisted extraction (0-450 W) in simultaneously enhancing the extraction yield and modulating the physicochemical properties of PeMP. Results showed that ultrasound treatment at 150 W achieved a maximal extraction yield of 76.23%, significantly outperforming the alkali-soluble acid precipitation method. Structural characterization, including SDS-PAGE and LC-MS/MS, revealed that ultrasonic cavitation induced controlled protein unfolding without disrupting the primary peptide chain. This process reduced the content of rigid α-helices and significantly increased surface hydrophobicity. These conformational changes markedly improved the interfacial behavior of PeMP: appropriately ultrasound-modified (150 and 300 W) fractions exhibited superior solubility, emulsifying activity, and foaming stability compared to commercial soy protein isolate (SPI), while maintaining comparable water- and oil-holding capacities. Although the essential amino acid ratio was slightly lower than that of SPI, it fully met the FAO/WHO requirements for adult nutrition. Furthermore, the structural loosening exposed enzyme cleavage sites, leading to a significant enhancement in vitro digestibility. Overall, this study demonstrates that ultrasound-assisted extraction acts as a robust dual-function strategy for producing high-quality mycelium protein with tailored functionalities, offering a viable plant-based alternative for the food industry.
Kai Zhou, Qingyue Wang, Qiaozhi Li et al.· International Journal of Bio...· 0 citations
Differences in the composition, microstructure, infrared spectral characteristics, and enzymatic hydrolysis properties of rice bran protein extracted by four methods were investigated, and the antioxidant and anti-photoaging activities of peptides derived from the resulting hydrolysates were further evaluated. Rice bran protein obtained via ultrasonic pretreatment combined with alkaline solublilization and acid precipitation (URP) exhibited relatively high purity (59.17%) and extraction yield (47.61%), together with increased surface porosity, enhanced hydration capacity, and improved enzymatic hydrolysis performance. The URP hydrolysate (URPP) showed a protein content of 81.00%, a degree of hydrolysis of 33.57%, and marked antioxidant activity (ABTS, 684.21; ORAC, 2016.15 μmol TE/g sample). The identified peptides were predominantly short and enriched in hydrophobic amino acids. Structural analysis suggested that the indole N-H group of tryptophan may play an important role in the antioxidant activity of these peptides. Moreover, these peptides alleviated UVB-induced photoaging in HaCaT cells by reducing oxidative stress and inflammatory responses and downregulating the mRNA expressions of AP-1, MMP-1 and MMP-3. Overall, these findings reveal an association between the extraction method, structural characteristics, and enzymatic hydrolysis properties of rice bran protein and the biological activities of its derived peptides, providing a basis for the high-value utilization of rice bran protein and the development of antioxidant and anti-photoaging functional ingredients.
