Effect of high hydrostatic pressure on in vitro digestibility and techno-functional properties of fava bean (Vicia faba L.) protein

Tailoring the structure-functionality and volatile properties of pea protein isolate by high-pressure homogenization: Impact of pass number and pressure.

Pea protein is increasingly used in food formulations due to its nutritional value and sustainability. However, its limited solubility, weak interfacial properties, and undesirable off-flavors remain major constraints for broader application. In this study, pea protein isolate (PPI) was subjected to multi-stage high-pressure homogenization (HPH) at pressures ranging from 100/1000 psi to 500/5000 psi with various pass numbers (1, 2, and 3) to examine how processing intensity affects its structural, functional, and volatile properties. SDS-PAGE showed no detectable changes in molecular weight distribution, whereas FTIR, particle size distribution, and zeta potential analyses collectively indicated that HPH induced subtle physicochemical modifications in PPI. These modifications improved functional properties, particularly solubility, which increased from 83.18% in the untreated sample to 88.14% under optimized conditions. Enhancements in foaming capacity and emulsifying activity were also observed, most prominently at 500/5000 psi, although excessive processing resulted in a slight decline in foaming performance. In contrast, emulsifying stability remained largely unchanged across conditions. Furthermore, GC-MS was used to evaluate the changes in the volatile profile of PPI after HPH treatment. Seven major compounds dominated by lipid oxidation products were identified. Their relative abundances varied with homogenization conditions with pressure exerting a more pronounced influence than pass number. Overall, HPH effectively tailored the properties of PPI by reducing particle size, improving solubility and interfacial properties, and altering its volatile profile, although at higher homogenization pressures the potential trade-off between functionality and oxidative flavor stability needs to be considered.

Improvement of Functional Properties and In Vitro Digestibility of Durum Wheat, Chickpea, and Amaranth Flours Using Power Ultrasound

Ultrasound technology has emerged as a promising non-thermal approach for modifying the structural and functional properties of food matrices. However, its impact on starch digestibility remains insufficiently understood, particularly in complex systems such as cereal, legume, and pseudocereal flours. This study evaluated the effect of power ultrasound on the functional properties and in vitro digestibility of durum wheat (DWF), chickpea (CF), and amaranth (AF) flours. Flours were treated using an ultrasonic probe (20 kHz, 60% amplitude) for 10 and 20 min while maintaining the sample temperature at 15 °C. Structural and functional properties were assessed, including color, morphology, water absorption, FT-IR spectra, pasting behavior, thermal properties, and starch fractions. Ultrasound induced structural modifications, including starch granule disruption and increased surface roughness. Lightness increased in DWF, CF, and AF, although the magnitude of the response differed among flour types. Water absorption improved in DWF but decreased in CF and AF. FT-IR spectra suggested molecular rearrangements, while viscoelastic and thermal analyses showed increased viscosity in DWF and CF and reduced viscosity in AF. Ultrasound also modified starch fractions and in vitro starch digestibility in a flour-dependent manner, reflecting the distinct structural responses of cereal, legume, and pseudocereal starches to acoustic cavitation. Overall, ultrasound modified the functionality of flour and starch digestibility in a matrix-dependent manner, supporting its potential as a clean-label technology for tailoring the functional properties of different flour matrices.

Bioprocessing of Wheat Bran by Combined Extrusion and Solid-State Fermentation: Impact on Biopolymer Physicochemical and Functional Properties

This study aimed to investigate the effects of thermo-mechanical treatment and solid-state fermentation (SSF) on the structural, physicochemical, and techno-functional characteristics of wheat bran (WB), with a particular emphasis on specific isolated protein fractions, starch, and dietary fibre. WB was subjected to extrusion at different temperatures (90, 115, and 130 °C) and screw speeds (16 and 25 rpm), followed by a 24-h SSF with Liquorilactobacillus uvarum. Changes in chemical composition, hydration properties (water absorption, solubility, swelling capacity), temperature-dependent (30–80 °C) extract viscosity, as well as protein extraction yields and in vitro protein digestibility of isolated protein fractions were systematically evaluated. Extrusion reduced insoluble dietary fibre (IDF) content by 15.7–33.9%, while increasing soluble dietary fibre (SDF) content by 59.1–94.2%, and SSF with L. uvarum additionally increased the SDF fraction by 6.5–7.9%. Regarding technological properties, extrusion increased WB water solubility (WS) up to 14.6%, and 24-h fermentation further enhanced WS, reaching up to 16.3%. Extrusion increased the degree of starch gelatinisation up to 49.1%, whereas fermentation reduced it to 40.7% and decreased the WB extract viscosity by 18.3–24.6%. Furthermore, 24-h SSF enhanced the in vitro digestibility of globulin, gliadin, and glutenin fractions from initial values of 71.3–78.8%, 70.6–75.2%, and 70.2–73.0% to 82.0–85.6%, 83.3–88.6%, and 79.4–89.0%, respectively. The observed thermo-induced thickening and enhanced digestibility suggest that modified wheat bran has potential as a functional bio-ingredient for future application in novel food formulations.

Ultrasound-assisted extraction enhances functional properties and in vitro digestibility of Pleurotus eryngii mycelium protein: The role of structural unfolding.

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.

Combined Effect of High-Pressure Homogenization and pH on the Techno-Functional Properties of a Commercial Pea Protein Concentrate

High-pressure homogenization improves mycoprotein digestibility under an elderly static in vitro digestion model by disrupting cell-wall-related structural barriers.

Mycoprotein, with a balanced amino acid profile and potential benefits for muscle maintenance, is a promising protein source for elderly-friendly high-protein foods. Yet, rigid fungal cell walls and entangled hyphal networks enclosing intracellular proteins may restrict enzymatic accessibility under elderly digestive conditions. In this study, high-pressure homogenization (HPH) was applied as a food-grade structural regulation strategy to improve the digestive adaptability of mycoprotein. Native mycoprotein (MYC), HPH-treated mycoprotein (HMYC), pork (PORK), and commercial plant-based meat (PLANT) were evaluated using a static in vitro oral-gastric-intestinal digestion model simulating elderly physiological conditions. Structural disintegration, hydrolysis behavior, free amino acid release, multiple light scattering, and microrheological properties were analyzed to elucidate digestive adaptation mechanisms. HPH markedly disrupted the cell-wall-associated and hypha-entangled structure of mycoprotein without significantly altering its major nutrient composition, thereby improving enzyme accessibility and digestion-induced disintegration. During gastric and intestinal digestion, the particle size D[4,3] of HMYC decreased by over 80%, indicating enhanced structural breakdown efficiency. HMYC exhibited a significantly higher hydrolysis degree than MYC, while its free amino acid release approached that of PORK and exceeded those of both MYC and PLANT. Multiple light scattering revealed improved enzyme-substrate interaction and greater physical structural transformation after HPH treatment. Microrheological analysis further confirmed improved restructuring behavior and reduced structural resistance during digestion. Overall, HPH effectively improved the digestive adaptability of mycoprotein under elderly digestive conditions, making its digestive behavior closer to that of PORK, while the distinct digestion behavior of PLANT was mainly associated with matrix effects from added lipids and hydrocolloids, supporting the development of elderly-friendly mycoprotein-based foods.