Ultrasound-Assisted Extraction of Protein from Pumpkin Seed Press Cake: Impact on Protein Yield and Techno-Functionality

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.

Effects of ultrasound and high-pressure assisted extraction of pearl millet protein isolate: Functional, digestibility, and structural properties

This study explores the effect of individual and combination treatments of ultrasound (US) and high pressure (HP) on the extraction of pearl millet protein isolate (PMPI). Compared to the conventional extraction technique (control) the millets treated with non-thermal techniques provided a higher protein recovery percentage. The highest recovery of 63.43 % was observed in the high-pressure and ultrasound combination (HU) treatment. The solubility of PMPI was significantly enhanced in all pH levels, the highest solubility was observed at pH 10. Combination treatments demonstrated superior functional properties, including emulsifying capacity, foaming property, surface hydrophobicity, water-holding capacity (WHC), and oil-holding capacity (OHC) compared to individual treatments and control. Significant improvement in protein in-vitro digestibility (IVPD) was identified in non-thermal treated PMPI. The involvement of nonthermal techniques for protein extraction significantly altered the protein's secondary structure, surface characteristics, and molecular weight. These findings underscore the application and advantage of combination treatments in the extraction of millet protein isolates.

Optimization of ultrasound-assisted extraction of faba bean protein isolate: Structural, functional, and thermal properties. Part 2/2

Environmental concerns linked to animal-based protein production have intensified interest in sustainable alternatives, with a focus on underutilized plant proteins. Faba beans, primarily used for animal feed, offer a high-quality protein source with promising bioactive compounds for food applications. This study explores the efficacy of ultrasound-assisted extraction under optimal conditions (123 W power, 1:15 g/mL solute/solvent ratio, 41 min sonication, 623 mL total volume) to isolate faba bean protein (U-FBPI). The ultrasound-assisted method achieved a protein extraction yield of 19.75 % and a protein content of 92.87 %, outperforming the control method's yield of 16.41 % and protein content of 89.88 %. Electrophoretic analysis confirmed no significant changes in the primary structure of U-FBPI compared to the control. However, Fourier-transform infrared spectroscopy revealed modifications in the secondary structure due to ultrasound treatment. The U-FBPI demonstrated superior water and oil holding capacities compared to the control protein isolate, although its foaming capacity was reduced by ultrasound. Thermal analysis indicated minimal impact on the protein's thermal properties under the applied ultrasound conditions. This research highlights the potential of ultrasound-assisted extraction for improving the functional properties of faba bean protein isolates, presenting a viable approach for advancing plant-based food production and contributing to sustainable protein consumption.

Physicochemical and functional characteristics of a gourd (Cucurbita argyrosperma Huber) seed protein isolate subjected to high-intensity ultrasound

The impact of high-intensity ultrasound (HIU, 20 kHz) on the physicochemical and functional characteristics of gourd seed protein isolate (GoSPI) was studied. GoSPI was prepared from oil-free gourd seed flour through alkaline extraction (pH 11) and subsequent isoelectric precipitation (pH 4). The crude protein concentration of GoSPI ranged from 91.56 ± 0.17 % to 95.43 ± 0.18 %. Aqueous suspensions of GoSPI (1:3.5 w/v) were ultrasonicated at powers of 200, 400, and 600 W for 15 and 30 min. Glutelins (76.18 ± 0.15 %) were the major protein fraction in GoSPI. HIU decreased the moisture, ash, ether extract, and nitrogen-free extract contents and the hue angle, available water and a* and b* color parameters of the GoSPI in some treatments. The L* color parameter increased (7.70 %) after ultrasonication. HIU reduced the bulk density (52.63 %) and particle diameter (39.45 %), as confirmed by scanning electron microscopy, indicating that ultrasonication dissociated macromolecular aggregates in GoSPI. These structural changes enhanced the oil retention capacity and foam stability by up to 62.60 and 6.84 %, respectively, while the increases in the solvability, water retention capacity, and emulsifying activity index of GoSPI were 90.10, 19.80, and 43.34 %, respectively. The gelation, foaming capacity, and stability index of the emulsion showed no improvement due to HIU. HIU altered the secondary structure of GoSPI by decreasing the content of α-helices (49.66 %) and increasing the content of β-sheets (52.00 %) and β-turns (65.00 %). The electrophoretic profile of the GoSPI was not changed by HIU. The ultrasonicated GoSPI had greater functional attributes than those of the control GoSPI and could therefore be used as a functional food component.

Oilseed meal proteins: From novel extraction methods to nanocarriers of bioactive compounds

The global demand for animal proteins is predicted to increase twofold by 2050. This has led to growing environmental and health apprehensions, thereby prompting the appraisal of alternative protein sources. Oilseed meals present a promising alternative due to their abundance in global production and inherent dietary protein content. The alkaline extraction remains the preferred technique for protein extraction from oilseed meals in commercial processes. However, the combination of innovative techniques has proven to be more effective in the recovery and functional modification of oilseed meal proteins (OMPs), resulting in improved protein quality and reduced allergenicity and environmental hazards. This manuscript explores the extraction of valuable proteins from sustainable sources, specifically by-products from the oil processing industry, using emerging technologies. Chemical structure, nutritional value, and functional properties of the main OMPs are evaluated with a particular focus on their potential application as nanocarriers for bioactive compounds.

Plant-based proteins from agro-industrial waste and by-products: Towards a more circular economy

There is a pressing need for affordable, abundant, and sustainable sources of proteins to address the rising nutrient demands of a growing global population. The food and agriculture sectors produce significant quantities of waste and by-products during the growing, harvesting, storing, transporting, and processing of raw materials. These waste and by-products can sometimes be converted into valuable protein-rich ingredients with excellent functional and nutritional attributes, thereby contributing to a more circular economy. This review critically assesses the potential for agro-industrial wastes and by-products to contribute to global protein requirements. Initially, we discuss the origins and molecular characteristics of plant proteins derived from agro-industrial waste and by-products. We then discuss the techno-functional attributes, extraction methods, and modification techniques that are applied to these plant proteins. Finally, challenges linked to the safety, allergenicity, anti-nutritional factors, digestibility, and sensory attributes of plant proteins derived from these sources are highlighted. The utilization of agro-industrial by-products and wastes as an economical, abundant, and sustainable protein source could contribute towards achieving the Sustainable Development Agenda's 2030 goal of a "zero hunger world", as well as mitigating fluctuations in food availability and prices, which have detrimental impacts on global food security and nutrition.

Optimization of ultrasound-assisted cellulase degradation method on the extraction of mulberry leaf protein and its effect on the functional characteristics

The mulberry leaf protein extracted by ultrasound-assisted cellulase degradation (UACD) method was optimized with the protein dissolution amount (PDA) as the index. The Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy of extracted mulberry leaf protein were measured. The functional characteristics of protein extracted by the UACD method were evaluated. Results showed that the extraction condition was optimized and adjusted to the following parameters: pH value of 7.20, ultrasound temperature of 35.00 °C, enzyme dosage of 4.20% and ultrasound time of 10.00 min. Under these optimized conditions, the experimental verification value of PDA was 13.87 mg/mL, which was approaching to the predicted value of 13.54 mg/mL. The analysis results of FTIR showed that after extraction by the UACD method, the mulberry leaf protein with the vibrational peak of ester carbonyl (C = O) absorption peak (1734.66 cm-1) disappeared. The α-helix content of protein extracted by the UACD decreased by 8.13%, and the β-turn and random coil content of protein increased by 20.22% and 18.79%, respectively, compared to that of the blank. The microstructure of mulberry leaf protein showed that the UACD method could break the dense structure of protein raw materials, reduce the average size of proteins and increase the specific surface area and roughness of proteins. According to the results of functional characteristics, the mulberry leaf protein extracted by the UACD method presented the highest enzymolysis properties and solubility, which was beneficial for the application in the food industry. In conclusion, the UACD method was a very effective way to extract protein from mulberry leaf.

Mechanism of ultrasonic combined with different fields on protein complex system and its effect on its functional characteristics and application: A review

In recent years, new food processing technologies (such as ultrasound, high-pressure homogenization, and pulsed electric fields) have gradually appeared in the public 's field of vision. These technologies have made outstanding contributions to changing the structure and function of protein complexes. As a relatively mature physical field, ultrasound has been widely used in food-related fields. However, with the gradual deepening of related research, it is found that the combination of different fields often makes some characteristics of the product better than the product under the action of a single field, which will not only lead to a broader application prospect of the product, but also make the product a better solution in some special fields. There are usually synergistic and antagonistic effects when multiple fields are combined, and these effects will also gradually enlarge the interaction between different components of the protein complex system. In this paper, while explaining the mechanism of ultrasonic combined with other fields affecting the steric hindrance and shielding site of protein complex system, we will further explain the effect of this effect on the function and application of protein complex system.