Protein Extraction Yield Research Articles

High-intensity ultrasound-assisted extraction for functionalized pistachio meal protein concentrate.

The residues left over from cold-pressing oilseeds and fruits offer a promising source of plant proteins, serving as an alternative resource within the circular economy framework. This research aims to develop protein concentrates (PCs) from pistachio meal with enhanced functional properties using ultrasound -assisted extraction (UAE). A response surface methodology was employed to optimize UAE considering power (200-600W), time (5-25min), and pH (8-11). Through a Box-Behnken experimental design, the optimal extraction conditions were determined as 595W, pH 11, and 19min, targeting maximal protein extraction yield (R2: 0.9359, desirability of 0.993). Under these ideal conditions, UAE achieved higher protein extraction yield (51%), compared to the conventional alkaline extraction (AE) (39%). Protein recovery rate increased from 33.1% to 44% by UAE. PCs obtained through the AE (PC-AE) and optimal UAE (PC-UAE) were evaluated for their functional, structural, and morphological properties. UAE significantly improved the emulsion activity index of the PC-UAE by 34.9% (p<0.05), whereas solubility and foaming activity showed slight increases compared to PC-AE (p>0.05). US-induced size reduction as observed by smaller and irregular particles in morphological analysis. The Fourier-transform infrared spectroscopy spectra, analyzed using a curve-fitting approach on the second derivative, revealed hidden peaks that highlighted changes in the secondary structure of the PCs, including slight shifts in characteristic wavenumbers and variations in the proportional amounts of β-sheet, α-helix, and random coil structures. This study demonstrated that UAE achieved similar protein purity as AE while producing larger quantities through higher recovery of proteins with improved functional properties. PRACTICAL APPLICATION: Ultrasound-assisted alkaline extraction significantly boosts protein extraction yield and recovery from pistachio meal and enhances functional properties (especially emulsion activity) of the extracted proteins. These improvements make the UAE protein concentrates suitable for applications in food formulations, such as plant-based beverages and emulsified products. UAE offers a sustainable approach to valorize oilseed residues in the context of circular economy.

Impact of a Novel Two-Phase Natural Deep Eutectic Solvent-Assisted Extraction on the Structural, Functional, and Flavor Properties of Hemp Protein Isolates.

Defatting dehulled hemp seeds is a crucial step prior to protein extraction. However, conventional methods rely on flammable solvents, posing significant health, safety, and environmental concerns. Additionally, hemp protein has poor extractability, challenging functionality, and flavor limitations, restricting its broader application in foods. Accordingly, a two-phase natural deep eutectic solvent (NADES)-assisted extraction was evaluated as a solvent-free alternative for co-extracting protein and oil from full-fat hemp flour. In comparison to the reference hemp protein isolate (R-HPI), produced from hexane-defatted flour following conventional alkaline extraction, NADES-extracted hemp protein isolate (N-HPI) had significantly higher protein extraction yield and purity. N-HPI exhibited enhanced surface charge, lower hydrophobicity, and thus higher solubility at an acidic pH compared to R-HPI. N-HPI had a higher abundance of edestin and lower levels of vicilin-like proteins, which contributed to superior gelation compared to R-HPI. N-HPI, compared to R-HPI, contained lower levels of lipid-derived off-flavor compounds, such as aldehydes, alcohols, and ketones. These findings highlighted, for the first time, the potential of a two-phase NADES-assisted extraction as a sustainable alternate and effective process for producing high-quality, functional hemp protein. The development of such a green process is an impetus for broadening the applications of hemp protein in food systems.

Impact of pH on the Physicochemical, Structural, and Techno-Functional Properties of Sesame Protein Isolate.

Sesame protein isolate (SPI) is a highly nutritious plant protein distinguished by its essential amino acid profile. This study investigates the influence of pH on SPI's physicochemical, structural, and techno-functional properties, highlighting its potential as a sustainable protein source for various food applications. Our findings revealed that SPI had a protein content of 90.60% and a protein extraction yield of 77.2%. The density is measured at 0.72 g/mL, with a critical compressibility index of 19.22, indicating excellent flowability for weaning foods. Notably, the ζ-potential shifts from +39 mV at pH 3.0 to 0 at the isoelectric point (pI, 5-5.5) and becomes negative at higher pH levels. We observed a direct correlation between solubility, fluorescence intensity, and functional characteristics of SPI, with peak solubility and functional properties at acidic and alkaline pH levels and lowest values at the pI. Structural analyses confirmed the relationship between electrical charge, hydrophobicity, and functional attributes, with the highest surface hydrophobicity observed at pH 2.0. In conclusion, our findings underscore the critical role of pH in modulating the physicochemical properties of sesame protein isolate, enhancing its applicability in food formulations. SPI demonstrates significant potential as a versatile ingredient in the functional food product development.

Characterizing the extractable proteins from tomato leaves - A proteomics study.

The ambition to utilize agricultural by-products has spotlighted tomato leaves as a promising source for plant-based proteins. High-yielding protein extractability is key for its industrial use, but previous studies reported decreased protein extractability at later stages of plant development. This study investigated the underlying factors in protein extractability through a comprehensive proteomics analysis across four plant developmental stages (vegetative, flowering, fruit-forming, mature-fruit). The findings linked reduced yields to a shift in leaf function, from anabolic to catabolic processes and (a)biotic stress responses. This functional shift is accompanied by decreased protein synthesis and increased protein degradation, leading to an overall decrease of the soluble protein fraction. Furthermore, incomplete extraction of soluble proteins from leaves of later developmental stages, suggested the presence of inhibitory molecules hindering the extraction process. These findings indicate that breeding strategies towards increased amounts of soluble proteins and reduced concentration of inhibitory molecules could enhance protein extraction yields.

Optimization of Black Garlic Protein Extraction Process and Exploration of Its Properties and Functions with Enzymatic Hydrolysis Products.

This study optimized the process of extracting protein from black garlic using an alkaline dissolution and acid precipitation method through response surface methodology. The optimal extraction conditions were determined as a solid-to-liquid ratio of 1:50, an extraction time of 100 min, an extraction temperature of 30 °C, and an alkaline extraction pH of 9.0. Under these optimized conditions, the actual black garlic protein (BGP) extraction yield was 12.10% ± 0.21%, and the isoelectric point of the obtained BGP was 3.1. Subsequently, this study extracted black garlic protein under optimal conditions and subjected it to enzymatic hydrolysis using different enzymes (trypsin, pepsin, and their mixed enzymes). The functional characteristics, antioxidant activity, and hypoglycemic activity of black garlic protein before and after enzymatic hydrolysis were compared. Among the hydrolysates, the pepsin hydrolysate (BGPH-P) had the smallest particle size (188.57 ± 1.93 nm) and the highest Zeta potential (-29.93 ± 0.42 mV). Scanning electron microscopy showed that BGPH-P had the smallest and most dispersed particles. Fourier-transform infrared (FTIR) spectroscopy revealed that the dual enzymatic hydrolysis hydrolysate (BGPH-PT) exhibited the most stable structure. Compared to BGP, the hydrolysates demonstrated significantly improved solubility, water-holding capacity, and foaming ability (p < 0.05), while their emulsifying activity, emulsion stability, DPPH radical scavenging capacity, and hypoglycemic activity decreased. In summary, the BGP extracted using the optimized process demonstrated good antioxidant and hypoglycemic activities, while its enzymatic hydrolysate BGPH-P exhibited excellent solubility, water-holding capacity, and emulsifying properties, providing valuable insights for the further development of black garlic protein and its hydrolysates.

Effects of salt concentration, temperature, and blanching time on insect protein extraction yield: optimisation by response surface methodology

Abstract This study aimed to optimise the protein extraction yield from black soldier fly larvae by employing a blanching process to enhance protein solubility and mitigate oxidation. Through response surface methodology, we determined the optimal blanching conditions, with the temperature set at 85.152 °C, a duration of 12.411 s, and a sodium chloride concentration of 0.46 M. These parameters were selected to maximise protein solubility while minimising oxidation. The results of this study reveal significant improvements in protein functionality after blanching, particularly with respect to increased emulsification stability. Notably, no significant effect on foam formation was observed. These findings underscore the efficacy of blanching as a pre-processing step to enhance the quality of proteins extracted from black soldier fly larvae. Moreover, these optimised conditions have promising applications in various food and feed formulations, contributing to sustainable protein sourcing and processing methods. By addressing key challenges related to food security and environmental sustainability, this study provides valuable insights into the utilisation of insect proteins as an alternative protein source in the face of global challenges, such as climate change and dwindling natural resources.

Effects of Chlamydomonas reinhardtii (Dangeard) Proteins Extracts on Storage Stability of Freshwater Shrimp Macrobrachium nipponense (De Haan)

In this study, the extraction of Chlamydomonas reinhardtii Dangeard (C. reinhardtii) protein was optimized through response surface methodology. The optimal extractions parameters were 0.091 mol/L sodium chloride concentration, 31.02 mL/g liquid to solid ratio, a homogenization frequency of 10.17 times per second, and a homogenization time of 12.82 minutes. The optimized protein extraction yield was 52.78%. The C. reinhardtii protein extract at different concentrations (0.1-0.5%) was used to dip-coat East Asian river prawn (Macrobrachium nipponense De Haan). Over a 4-day storage period, the pH value and total viable counts (TVC) of the prawn samples were determined every 24 hours. Results showed that a 0.2% C. reinhardtii protein extract effectively delayed increases in pH and TVC of the prawn samples, suggesting that C. reinhardtii protein extract could be a promising natural preservative.

Enhancing Scalability and Consistency in Pulsed Electric Field Processing of Microalgae: Integrating Single-Cell Suspension Rheology and Multiphysics Simulation

Emerging extraction technologies such as microsecond pulsed electric field (μsPEF) offer an energy-efficient and gentle method for downstream processing of single cells. However, attaining consistent processing outcomes in continuous PEF systems across different scales is challenging due to variations in cell residence times caused by cell concentration and flow-dependent rheological behavior. This study employed COMSOL Multiphysics® simulations to model rheological changes in high-density heterotrophically grown Auxenochlorella protothecoides microalgae suspensions. The model was designed to precisely estimate residence times for consistent μsPEF treatment and increased processing capacity at high flow rates and cell concentrations. Implementing the simulated residence times into experimental validations achieved consistent treatment outcomes, resulting in 86 ± 4% of cells being permeabilized and increased processing capacity from 21 to 300 mL min-1. Higher cell concentrations led to increased energy input and decreased protein extraction yields, indicating complex underlying permeabilization and diffusion processes during and after treatment. This work advances scalable and consistent μsPEF technology for single-cell downstream processing by applying cell suspension rheology and residence time simulations.

Protein extraction from yellow mealworm (Tenebrio molitor) assisted by pulsed electric fields: Effect on foaming properties

This study focuses on the use of Pulsed Electric Field (PEF) as a non-thermal technology to extract proteins from defatted Yellow Mealworm (Tenebrio molitor) meal. Additionally, the effect of PEF on the foaming properties of the extracted proteins was evaluated. An experimental design with two-factors and two levels, including the central point, was carried out: electric field (E: 1.5, 3.125 and 5 kV/cm) and number of pulses (N: 200, 1100 and 2000). The response variables studied were the protein extraction yield, the foam capacity (FC), and the foam stability constant (k) that was calculated by fitting the foam stability (FS) over the time to a first order exponential decrement equation. A positive effect of the crossed factor (EN) to the protein yield was found. Moreover, an increment of 27 % of the protein yield was observed when comparing PEF-based extracts to the control. Our results indicated that PEF contributed to reduce the molecular weight of the extracted proteins when compared with the control. Moreover, PEF induced modification of the protein structure as indicated by a reduction in fluorescence and content of β-sheet. The changes observed have an impact on the foaming properties measured, especially on FS which has decreased when applying PEF.

PH shift extraction technique for plant proteins: A promising technique for sustainable development

With the recognition of animal-derived foods as unhealthy and their association with climate change, researchers are increasingly focusing on plant-based protein as a sustainable alternative. Plant proteins offer versatile functional and dietary benefits, making them suitable for various food applications. This study investigates the influence of alkaline and acidic pH conditions on the extraction yield and the functional and nutritional properties of plant-based proteins. The primary sources of plant protein include cereals, legumes, and oilseeds, which can be used to address essential amino acid deficiencies through blending. Several methods have been employed for protein extraction from plant sources, such as salt extraction, microwave-assisted extraction, ultrasound-assisted extraction, and micellar precipitation. Among these techniques, the pH shift method stands out due to its non-thermal nature, sustainability, and cost-effectiveness. In this method, proteins are solubilized at alkaline pH and then precipitated at their isoelectric point, resulting in a collection of protein precipitate. It is crucial to optimize extraction techniques based on qualitative and quantitative analysis to enhance protein yield, characteristics, and nutritional value. Most conventional protein extraction methods require a large quantity of chemicals, which imposes the issue of safe disposal, compromising environmental sustainability. Traditional methods also produce protein with non-proteinaceous constituents, adding another purification step and resulting in increased overall cost. However, the pH shift method utilizes comparatively less harsh chemicals and has a high protein extraction yield, which makes it comparatively more environmentally and economically sustainable. The sustainable extraction of plant-based proteins addresses the health and environmental concerns associated with animal-derived foods and offers a promising solution to promote sustainability in the food industry.

Prone to loss: Senescence-regulated protein degradation leads to lower protein extractability in aging tomato leaves

The utilization of proteins extracted from tomato (Solanum lycopersicum) leaves as cost-effective resources for human consumption or animal feed has gained interest. Thus, increasing protein extractability from tomato leaves became a new breeding target. However, the genetic factors influencing this trait remains poorly understood. In this study, we analyzed changes in leaf protein content, protein composition, and extraction yield across developmental stages, which are vegetative growth, flowering, fruit-forming, and mature fruit. Moreover, tomato gene expression across developmental stages was also studied, to identify genes underlying variability in leaf protein extraction. Protein extraction yield decreased from 0.51 g/g to 0.01 g/g leaf protein from the vegetative to mature stage. However, total protein content inferred with Dumas combustion analysis did not change over the developmental stages tested, while the protein-to-peptide ratio decreased significantly. To further analyze potential causes underlying the decline of protein-to-peptide ratio, the enzymatic activity of proteases – i.e. the enzymes responsible for protein degradation – and the expression of genes encoding these enzymes was studied along plant development. The overall specific activity of proteases did not change significantly throughout plant development. On the contrary, the gene expression of distinct members of the aspartic, cysteine, and subtilase protease families increased. Overall, our findings suggest that extraplastidic protein degradation likely underlies the protein degradation observed during senescence. In the future, the reduction of the activity of extraplastidic proteases through biotechnology could represent an effective strategy to develop tomato varieties with improved protein extraction yields.

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.

Impact of Seed Germination on the Physicochemical Properties of Lupin Flours and the Physicochemical and Techno-functional Properties of Their Protein Isolates

Nowadays, lupin seeds have emerged as a novel and valuable source of proteins representing a sustainable alternative to current raw materials of plant-based proteins, such as soybean. In this regard, lupin demonstrates superior adaptation to the Mediterranean climate with improved tolerance to water stress. However, its suitability for human consumption is limited due to the presence of anti-nutritional and anti-technological factors, including alkaloids, polyphenols, tannins, and lipids, which can have adverse nutritional consequences and/or impact on the purity and yield of protein extraction. In this study, the Lupinus luteus seeds were germinated for 1, 2, 3, and 6 days and the effect of germination on the anti-nutritional and anti-technological factors of flours and derived protein isolates was analyzed. Additionally, changes on techno-functional properties of lupin protein isolates were also studied. Results showed that prolonged germination decreased fat content whereas antioxidant activity, polyphenols, saponin, and alkaloid content of flours increased. However, alkaloids were completely removed during protein extraction. Furthermore, protein isolates derived from germinated seeds exhibited higher water and oil absorption capacities, as well as improved foaming and emulsifying capabilities in comparison to isolates from non-germinated seeds. Nevertheless, prolonged germination periods were associated with diminished foam and emulsion stability. Therefore, germination of lupin seeds for no longer than 3 days should be recommended in order to minimize the levels of anti-nutritional and anti-technological factors, while enhancing techno-functional properties of the isolate.

Continuous pulsed electric field processing for intensification of aqueous extraction of protein from fresh green seaweed Ulva sp. biomass

The green marine macroalgae Ulva sp. can reach a high protein content and a high composition of essential amino acids. In this study, we have developed a novel device and investigated the parameters for a continuous Pulsed Electric Field (PEF) process, coupled with enzyme treatment followed by a spray drying, to facilitate the aqueous fractionation of Ulva protein. The process demonstrated 8.79 ± 0.58 (% w/w) protein extraction yield. Furthermore, the aqueous fractionation of protein exhibited a substantial 41.45% essential amino acid content and a branched amino acids composition of 17.58%. Additionally, it displayed an in vitro relative digestibility of 87.4 ± 1.36% compared to soy protein, along with a water holding capacity of 7.15 ± 0.17 g water/g sample and an oil holding capacity of 1.76 ± 0.11 g oil/g sample. These findings suggest that employing a continuous PEF process in conjunction with enzyme-induced cell wall degradation could position green marine macroalgae as an important potential source for food protein ingredients.

Techno-functional properties of Camelina sativa cake proteins treated with the instant controlled pressure drop (DIC) technology

The instant controlled pressure drop (DIC) is one of the emerging technologies in food that can affect the extraction and techno-functional properties of proteins. Camelina sativa cake was subjected to various DIC treatments, with pressure (0.2–0.7 MPa) and exposure time (20–60 s) variables. Afterwards, protein extraction was conducted, and the influence of individual or combined variables on the techno-functional properties of the protein concentrate was analyzed, and each treatment was later analyzed against the control. Furthermore, DIC increased the protein extraction yield. The pressure, time, and their interaction variables influenced the oil absorption capacity (OAC), foaming capacity (FC), and stability (FS), while water-holding capacity (WHC) was solely affected by pressure. The results of comparing DIC against control showed significant differences in OAC, emulsifying activity index (EAI), FS, and FC. These findings strongly indicate that DIC enhances protein extraction yield and modifies the techno-functional properties of camelina proteins.

Contribution of sequential pretreatments and enzyme-assisted extraction to rice bran protein yield improvement

Alcalase is commonly used in enzyme-assisted extraction of rice bran protein. However, broad handling of rice bran can affect proteins before proteolysis. Various pretreatments, including thermal stabilization, washing, defatting, alkaline extraction, and enzymatic cellulosic degradation, and combinations were identified regarding the present and possible handling processes of rice bran protein extraction to investigate their effects on the proteolysis of the protein afterward. Then, the protein extraction yield and proteolytic abilities were compared. The thermal stabilization of the rice bran strongly affects enzymatic protein extraction, which more elaborate extraction protocols can mitigate. Rice bran oil can be extracted earlier without seriously affecting the protein extraction. Washing removes native protease inhibitors and hence speeds up the protein extraction. Alkaline extraction is highly efficient but can cause protein denaturation, generating a challenging protein separation from the gel-like structure. The protein extraction with enzymatic (Ultimase) pretreatment is an efficient method that allows high hydrolysis of intact rice bran protein during the protein extraction step.

Valorization of Bombyx mori pupae and Moringa oleifera leaf as sources of alternative protein: Structural, functional and antioxidant properties

This study compared protein concentrates extracted from silkworm pupae (SPP) and moringa leaf (MLP) using alkaline extraction followed by isoelectric precipitation with commercial whey protein concentrate (WPC). SPP demonstrated higher protein extraction yield of 5.99 % and protein recovery of 66.02 % compared to MLP (4.39% and 55.27% of extraction yield and protein recovery, respectively). Proximate composition analysis revealed that SPP contained high protein of 65.40 % with ∼13 % fat content, while MLP had lower protein (48.70%) and fat content (0.33%). Particle size analysis showed small mean diameters of ∼123 nm for WPC, ∼192 nm for SPP, and ∼1485 nm for MLP with low polydispersity index (0.35 to 0.51). Secondary structure analysis highlighted β-sheet as predominant in WPC and MLP, while SPP exhibited a major β-turns structure. Solubility studies indicated that SPP had lowest solubility compared to others. In terms of functional properties, MLP exhibited the highest water and oil holding capacities, and foaming capacity, while SPP showed the greatest emulsifying capacity and stability. After passing simulated intestinal digestion, SPP exhibited the highest recovery of TPC, ABTS, DPPH, and FRAP. This study emphasizes the feasibility and advantages of utilizing SPP and MLP as food ingredients for various food applications.

Unlocking the potential of Extensin Signal peptide and Elastin-like polypeptide tag fused to Shigella dysenteriae's IpaDSTxB to improve protein expression and purification in Nicotiana tabacum and Medicagosativa

Plants are often seen as a potent tool in the recombinant protein production industry. However, unlike bacterial expression, it is not a popular method due to the low yield and difficulty of protein extraction and purification. Therefore, developing a new high efficient and easy to purify platform is crucial. One of the best approaches to make extraction easier is to utilize the Extensin Signal peptide (EXT) to translocate the recombinant protein to the outside of the cell, along with incorporating an Elastin-like polypeptide tag (ELP) to enhance purification and accumulation rates. In this research, we transiently expressed Shigella dysenteriae's IpaDSTxB fused to both NtEXT and ELP in both Nicotiana tabacum and Medicago sativa. Our results demonstrated that N. tabacum, with an average yield of 6.39 ng/μg TSP, outperforms M. sativa, which had an average yield of 3.58 ng/μg TSP. On the other hand, analyzing NtEXT signal peptide indicated that merging EXT to the constructs facilitates translocation of IpaDSTxB to the apoplast by 78.4% and 65.9% in N. tabacum and M. sativa, respectively. Conversely, the mean level for constructs without EXT was below 25% for both plants. Furthermore, investigation into the orientation of ELP showed that merging it to the C-terminal of IpaDSTxB leads to a higher accumulation rate in both N. tabacum and M. sativa by 1.39 and 1.28 times, respectively. It also facilitates purification rate by over 70% in comparison to 20% of the 6His tag. The results show a highly efficient and easy to purify platform for the expression of heterologous proteins in plant.

Integrating bead milling and alkaline solubilization for enhanced protein recovery from microalgae: A comprehensive approach

Microalgae, Chlorella vulgaris exhibits substantial potential as a sustainable food ingredient, but its robust cell wall and limited protein solubility hinder industrial scale protein recovery. A comprehensive solution was devised, integrating dry bead milling and alkaline solubilization. In this method, cells were initially disrupted with bead milling followed by alkali (NaOH) treatment. Without bead milling, protein extraction yield was very low (5.0 % with water, 16.8 % with 0.1 M NaOH) at a biomass loading of 20 g/L. However, the integrated approach significantly improved these results, achieving a maximum protein extraction yield of about 47.3 % at a biomass loading of 100 g/L. The optimized conditions for both dry bead milling (frequency 26 Hz, duration 1.0 h) and alkaline solubilization (biomass weight to NaOH molar ratio 200–250 (g/M), 37 °C, mixing time 1.0 h) played a pivotal role in realizing these improved results. This integrated approach effectively addresses the challenges and holds industrial relevance, offering a more efficient way to extract microalgal protein.

Surface activity of Lupinus angustifolius (blue lupine) seed extracts

Surface tension (γeq) of the seed extracts of four lupine cultivars showed values in the range 44.9–46.4 mN/m. The surface compression elasticity (E') of the adsorbed layers and foaming capacity (FC) also showed similar values (E' ∼ 30 mN/m, FC ∼ 100%). The effect of defatting prior to extraction at pH 8.5 depends on the solvent employed – hexane and dichloromethane improved the subsequent protein extraction yield, while ethanol reduced it. The effect of defatting on surface tension could be positive (for hexane and ethanol) or negative (for dichloromethane). Generally, defatting improved the surface compression rheological and foaming parameters. On the other hand, fractionation of the extracts obtained at pH 8.5 from hexane-defatted seeds did not improve significantly the surface activity parameters. Some improvement with respect to the unfractionated extracts was observed only for the extracts of undefatted seeds. γeq, E', E" and FC isotherms confirm the surfactant-like behavior of the lupine seed extracts.