Diffusion of tocopherols, phospholipids and sugars during oil extraction from sunflower collets using ethanol as solvent

Sunflower seed protein: defatting, structural characterization and property analysis

The preparation method and protein purity are crucial factors influencing the use of sunflower seed proteins in the food industry. In this study, sunflower seed press cake was defatted using subcritical butane, isopropyl alcohol and n-hexane, producing meal protein, protein concentrate, and protein isolate. A systematic analysis of the structural and functional properties of these proteins revealed that the subcritical butane and isopropyl alcohol extracted protein yield and color, protein structure was relatively loose, denaturation temperature was higher, the prepared sunflower seed protein solubility and other functional properties were better than traditional hexane extraction. Additionally, the protein isolate demonstrated superior solubility (46.38-52.34 %), emulsification stability (31.76-41.97 %), and oil holding capacity. The protein concentrate exhibited significant advantages in gel properties and water holding capacity. These findings supported the development of green, efficient, and sustainable methods for the optimal utilization of sunflower seed proteins at different purity levels.

High Pressure Extraction as a Green Alternative to the Conventional Sunflower Oil (Helianthus annuus) Production Process - Extraction with Pressurized Ethanol in an Intermittent Process and with Supercritical Fluid

This research explores green-technology alternatives to extract vegetable oils as alternatives to hexane, a non-renewable solvent, focussing on sunflower oil. It compares pressurized liquid extraction (PLE) with ethanol and supercritical fluid extraction (SFE) with CO2. Both processes aim to maximize oil yield, tocopherol content (α, β, γ, and δ), fatty acid profile (FA), and triacylglycerol (TAG) composition. Results show that SFE at 32 MPa achieves an 87.58% oil recovery, while PLE at 84 °C achieves 93.93%. PLE with ethanol extracts polar minority compounds along with the oil due to its higher temperature, favoring extraction. The total tocopherol content is 91.17 mg/100 g of oil in optimized SFE conditions, with α-tocopherol extraction influenced by temperature, γ and δ-tocopherol by pressure. PLE yields 83.16 mg/100 g of oil in tocopherols influenced less by process variables. The fatty acid (FA) profile do not vary in the oils obtained from different processes or based on the variables within each process, with linoleic and oleic acids being the most abundant. Similarly, triacylglycerols (TAGs) C54:5 and C54:6 are predominant. The optimization of SFE and PLE processes indicates a strong potential for using green solvents in the extraction of tocopherol-rich sunflower oil.

Effect of thermal and defatting treatments on the composition, protein profile and structure of house cricket (Acheta domesticus) protein extracts

This study investigated the impact of blanching (100 °C, 40 s), defatting method (maceration, Soxhlet) and solvent polarity (hexane, ethanol) on the profile, structure and solubility of house cricket protein extracts. Blanching and Soxhlet using ethanol impacted the protein profile, with a lower content of myosin heavy chain and a higher abundance of low molecular weight proteins (<25 kDa). Moreover, ethanol induced aggregation of non-blanched cricket proteins, with a 13-72% reduction in protein recovery yield. The protein secondary structure of non-blanched extracts was also affected by ethanol with 18% more β-sheets. Furthermore, blanching resulted in a lower protein surface hydrophobicity by a factor of 3 to 7, with no impact of solvent polarity. Finally, the solubility of protein extracts remained >75%, regardless of the blanching and defatting methods. These findings, combined with the evaluation of techno-functional properties, could be used for the development of cricket-based protein ingredients for food formulations.

An Evaluation of the Equilibrium Properties in Hexane and Ethanol Extractive Systems for Moringa oleifera Seeds and Fatty Acid Profiles of the Extracts

Until the present, oilseed extractions have been mainly performed using hexane: a toxic, non-sustainable solvent. Extraction methods using ethanol have recently been proposed and, to evaluate the suitability of ethanol as an alternative solvent, Moringa seeds with an oil content as high as 40% have been chosen to determine the equilibrium properties in solid–liquid ethanol extractions. The equilibrium constant (Keq) and the specific retained solution (M) of the extractive systems seeds–oil–hexane and seeds–oil–ethanol were determined and validated, following a counter-current multi-stage extraction model. The extractions were carried out at 40 and 50 °C, the mass to solvent ratios used were 1:5, 1:10 and 1:20, and shelled and unshelled seeds (kernels) were tested. The Keq and M of the different kinetics revealed that Keq was not infinite in the hexane systems, whereas the ethanol systems registered slightly lower values. Regarding M, although the seed powder allowed more rapid extractions, particle size was increased to reduce M for an easier phase preparation. Finally, a counter-current multi-stage extraction system was simulated and applied under suitable conditions. The fatty acid profiles for both types of extract were similar regarding their main components. definition:

Application of ultrasound for green extraction of proteins from spirulina. Mechanism, optimization, modeling, and industrial prospects

A green and innovative method, manothermosonication (MTS), for proteins extraction from dry Arthrospira platensis cyanobacteria assisted by ultrasound was designed in this work. Manothermosonication (probe, 20 kHz) was compared to a conventional process performed in the same conditions without ultrasounds. The extraction was carried out with a continuous flow rate at 15 mL/hour. Extraction parameters were optimized using a central composite design. Moreover, mathematic modelling and microscopic investigations were realized to allow a better understanding of ultrasound physical and structural effects on spirulina filaments and mass transfer phenomena over time. Crude extract and sections stained with toluidine blue were analyzed with optical and scanning electron microscopies. According to experimental results, MTS promoted mass transfer (high effective diffusivity, D_e) and enabled to get 229% more proteins (28.42 ± 1.15 g/100 g DW) than conventional process without ultrasound (8.63 ± 1.15 g/100 g DW). With 28.42 g of proteins per 100 g of dry spirulina biomass in the extract, a protein recovery rate of 50% was achieved in 6 effective minutes with a continuous MTS process. Microscopic observations showed that acoustic cavitation impacted spirulina filaments by different mechanisms such as fragmentation, sonoporation, detexturation. These various phenomena make extraction, release and solubilization of spirulina bioactive compounds easier.