Polyphenol removal from sunflower seed and kernel: Effect on functional and rheological properties of protein isolates (original) (raw)
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The influence of freeze and convection (at 40 and 50 °C) drying on the physical, functional, and rheological attributes of sunflower protein (SP) and its hydrolysate (SPH) was investigated. Compared with convectively-dried samples, the lightness, turbidity, bulk density, and particle size values of the freeze-dried SP and SPH were substantially higher, but the browning index was lower (p < 0.05). Additionally, freeze-dried samples exhibited good solubility and foaming characteristics, whereas lower emulsion properties with the most pH values were observed. Furthermore, SPHs possessed higher solubility as well as foamability over SPs under varying pH values (2.0–10.0), whilst reduction in the emulsion activity index was clearly observed (p < 0.05). Convectively-dried powders exhibited greater viscosity and consistency coefficient; and significantly lower flow behavior index of dispersions, relative to the respective freeze-dried preparations, indicating that dehydration methods...
Composition and properties of partially hydrolyzed sunflower protein isolates
Ukrainian Food Journal, 2016
Partial enzyme hydrolysis of proteins is common method of modification of their functional properties. The characteristics of partially hydrolyzed proteins obtained from sunflower meal are presented in this work. Materials and methods. Proteins of sunflower meal were extracted in the presence of two proteases viz. neutral protease and Alkalase during 40 min. Partially hydrolyzed protein samples were prepared by isoelectric precipitation and next drying. The polypeptide composition of protein isolates were studied by polyacrylamide gel electrophoresis, degree of protein hydrolysis, amino acid composition, surface activity and functional properties were estimated. Results and discussion. The polypeptides of higher molecular weight (45-54 and about 32-35 kDa) were absent in polypeptide profile of partially hydrolyzed proteins either of proteases. At the same time they were abounded with 14-16 kDa polypeptides and polypeptides with molecular weight lower 14 kDa. Partially hydrolyzed protein samples had higher protein content, lower content of ash and carbohydrates as compared with the control sample. The biological value of sunflower protein isolates were limited by three amino acids-sulfur containing amino acids (methionine and cysteine) and lysine. The content of methionine, cysteine and lysine has been increased in protein samples obtained with neutral protease, relative to protein isolate. Differential scanning calorimetric analyze of protein samples have demonstrated that partially hydrolyzed samples contained undenaturated proteins, but their denaturation degree was higher compared with control samples. Partial hydrolysis of sunflower seed proteins have improved their solubility in pH range from 2 to 8, water holding, oil binding, foaming, emulsifying capacities and surface activity. Conclusions. Partially hydrolyzed protein samples had higher protein content, lighter color, lower degree of denaturation and better functional properties compared to the traditional protein isolates.
The functional properties of three sunflower protein concentrates having different content of phenolic compounds (mainly chlorogenic and caffeic acids) obtained from sunflower oil cake, a by-product of the oil industry, were evaluated. Sunflower protein concentrates exhibited high water solubility and moderate water-imbibing and water-holding capacities. It was possible to obtain foams and emulsions of different stability at different pH and ionic strength from these protein concentrates, as well as self-supporting gels produced by thermal induction. The presence of phenolic compounds not only conferred antioxidant activity and changed the color of protein products, but also reduced the water imbibing capacity of sunflower protein concentrates, the stability of the emulsions obtained, and the hardness of protein gels. In contrast, phenolic compounds did not modify the water holding capacity, their water solubility or their foaming properties. These results suggest that these protein...
Food Production, Processing and Nutrition, 2021
Bioactive compounds including polyphenols (PP) have been observed to naturally form non-covalent complexation interactions with proteins under mild pH and temperature conditions, affecting protein structures and functionality. Previously, addition of Aronia berry PP to liquid dispersions containing whey protein isolate (WPI) and sucrose was found to alter characteristics including viscosity, surface tension, and particle sizes, with changes being attributed to protein-PP interactions. In this study we aimed to investigate whether Aronia PP would interact with soy and pea protein isolates (SPI and PPI, respectively) to a similar extent as with WPI in liquid protein-sucrose-PP mixtures. We hypothesized that formulations containing PPI (comprised of larger proteins) and hydrolyzed SPI (containing more carboxyl groups) may exhibit increased viscosities and decreased aggregate sizes due to enhanced protein-PP interactions. Concentrated liquid dispersions of varied ratios of protein to su...
Journal of The American Oil Chemists Society, 2011
Increasing the applications of industrial byproducts is of great interest. Therefore, in the present study, sunflower oil cake from a local oil manufacturing company was used to obtain soluble protein concentrates and isolates with different content of phenolic compounds. All the extraction procedures evaluated resulted in concentrates and isolates with water solubility higher than 75% but with different chemical composition, color and physicochemical properties (i.e. surface hydrophobicity, thermal stability, and polypeptide composition). Since no extraction process led to a complete extraction of phenolic compounds, all the products exhibited antioxidant activity, which depended on the concentration of such compounds. Phenolic compounds give a dark color to sunflower protein concentrates and isolates; nevertheless their final color tone was more dependent on the conditions used in the preparation process than on the amount of phenolic compounds in the product. The results demonstrate the value of sunflower industrial oil cake as a source of proteins with high water solubility, good physicochemical properties and antioxidant activity.
Industrial Crops and Products, 2018
Rapeseed (RSM) and sunflower (SFM) meals are highly abundant and protein-rich by-products from the oilseed industry. Besides their basic use as animal feed, they are seen nowadays as interesting raw materials for the production of high value added products such as protein isolates, peptides, emulsifiers and biomaterials. In other respects, they contain significant amounts of phenolic compounds exhibiting antioxidant or antimicrobial properties but widely untapped so far. Therefore, any process allowing the single-step separation of both the protein and phenolic parts of meals would be beneficial to the whole oilseed sector. To achieve this double objective this study attempted to separate the RSM and the SFM into their major constituents by using dry fractionation technologies. In a first step, ultrafine milling was applied to the meals. As a function of raw material type, the grid size turned out to be decisive on the particle size distribution and its modality. Then two separation technologies based either on particle charge (electrostatic sorting-ES) or density (turbo-separation-TS) were applied to the previously obtained fractions. Regardless the separation technique, the best results were obtained from fractions of an average particle diameter by mass (D 50) of 23.7 ± 1.0 μm and 105.5 ± 8.3 μm, for RSM and SFM respectively. Electrostatic sorting allowed increasing simultaneously the protein and phenolic contents by 50-55% and 80-100% for RSM and SFM respectively, while a lower increase was observed for turboseparation (23-29% and 58-64% for RSM and SFM respectively). Finally, depending on the process and meal types, the overall recovery yield of the most enriched fractions was in the range of 30-40%. (25-27 g/100 g DM) and phenolic compounds (≈2 g/100 g DM) (≈ 4 g/100 g DM). For both RSM and SFM, proteins and phenolic compounds are mainly present in the kernel (Carré et al., 2016; González-Pérez and Vereijken, 2007; Weisz et al., 2009) while lignin, cellulose, and hemicellulose are more concentrated in the hull (Cancalon, 1971; Carré et al., 2016). If meals are currently mostly intended for cattle feed, oleaginous proteins, especially from soybean, canola or sunflower, may be transformed into high added-value products such as bio-packaging or emulsifiers (Zhang and Mittal, 2010; Shi and Dumont, 2014) but also adhesives and fiberboards (Wang et al., 2014; Evon et al., 2015). Moreover, several studies have demonstrated the antioxidant activity of peptides from rapeseed meals protein
Food Science & Nutrition , 2023
In recent years, consumer demand for food has begun to shift from animal-based food to plant-based food as social trends are emphasizing health and wellness (Leyland, 2018). Many food companies seized the opportunity to innovate novel products, such as Love Raw promoted vegan chocolate, Beyond Meat developed and improved meat analog, and Food Nation introduced plant-based patty. These food products are composed of diverse ingredients, but proteins and polysaccharides usually play vital parts in improving the texture, structure, and stability of products. For instance, proteins contribute to the formation of emulsions, foams, and gels (He et al., 2014; Mesa et al., 2009) while polysaccharides have remarkable water-holding capacity, thickening property, and biodegradability, which have been regularly employed as gelling agents, stabilizers, thickeners, and texture modifiers (Jiang et al., 2019; Saha & Bhattacharya, 2010; Zhao et al., 2018). Several types of plant proteins and polysaccharides have been applied in the food industry, like soy protein isolate (SPI) and konjac glucomannan (KGM) are widely used as nonmeat ingredients of various meat analog products (Gao et al., 2015; Jiménez-Colmenero et al., 2012). However, other proteins such as peanut protein isolate (PNPI) and pea protein isolate (PPI) only occupy a relatively small part of the market due to their functional characters are incompletely discovered and developed. Isolated soy protein is considered as the most functional of the soy protein due to its desirable physiochemical and functional
Food Biophysics, 2015
This work is focused on physicochemical and emulsifying properties of pea (PP), chickpea (CP) and lentil (LP) proteins. We evaluated the molecular weight distributions, surface net charge, free sulfhydryl group (SH) and disulfide bond (SS) contents, protein solubility and thermal stability of the protein isolates. Their emulsifying properties (droplet size distribution, flocculation, coalescence and creaming) were also determined as function of pH values. The three protein isolates exhibit similar physicochemical properties, including good solubility and high thermal stability despite a high degree of denaturation. In addition, we analysed the influence of pH on stability of oil-in-water (O/W; 10 wt%/ 90 wt%) emulsions stabilized by the legume protein isolates. Concerning emulsifying ability and stability, the most unfavourable results for all three protein isolates relate to their isoelectric point (pI=4.5). A significant improvement in emulsion stability takes place as the pH value departs from the pI. Overall, this study indicates that pea, chickpea and lentil proteins have great potential as food emulsifiers.