Sunflower Meal Protein Research Articles

Effect of pH-Shifting on Sunflower Meal Protein Isolate: Improved Stability and Interfacial Properties of Chitosan-stabilized Pickering Emulsion

Effect of pH-Shifting on Sunflower Meal Protein Isolate: Improved Stability and Interfacial Properties of Chitosan-stabilized Pickering Emulsion

Nanobiocatalyst based on covalent immobilization of proteases onto functionalized nanocellulose for efficient production of sunflower meal protein hydrolysates

This study aimed to engineer bio-based and environmentally friendly nanobiocatalyst systems using commercially available protease preparations, Alcalase® 2.4L (Alcalase) and Flavourzyme® (Flavourzyme), along with functionalized cellulose nanocrystals (CNC). The study highlights the advantageous properties of the obtained glutaraldehyde-activated amino-modified CNC support (GA-amino-CNC), characterized as nanorods with dimensions ranging between 100-800 nm in length and 40-60 nm in width, particularly for protease immobilization. Maximum specific activity of immobilized Alcalase (15 IU/mg of proteins) was achieved at an initial enzyme concentration of 52 mg/g of support after 3 hours, with 80% of covalently attached enzyme molecules. In the case of Flavourzyme, maximum exo-hydrolytic activity of 21 L-pNAU/g of support was observed after 20 min, while a higher yield of covalently bound enzyme molecules (53%) detected after 1 hour. The covalently bound proteases on glutaraldehyde-activated amino-modified cellulose nanocrystals were evaluated for their efficacy in producing high-quality sunflower-based protein hydrolysates suitable for food and feed applications. Sequential hydrolysis of sunflower meal protein isolate (SMPI) using the developed nanobiocatalysts yielded a maximum hydrolysis degree of 20%. In addition, more than 80% of the initial activity of nanobiocatalysts were retained after 3 reuses, suggesting that these protease nanobiocatalysts have potential application in production of SMP hydrolysates.

Ultrasound-assisted macroporous resin treatment improves the color and functional properties of sunflower meal protein

Sunflower meal protein (SMP) has been considered as a high-quality source of plant protein. However, because the chlorogenic acid (CA) contained in sunflower seed meal was prone to oxidation reactions under traditional alkali extraction conditions, the extracted protein has a dark color and some poor functional properties. To this end, this study used ultrasound-assisted macroporous resin treatment to extract SMP. The improvement effects and potential mechanisms of ultrasonic-assisted macroporous resin treatment with different powers (100, 300, and 500 W) on the color and functional properties of SMP were studied. The results showed that compared with untreated sunflower meal protein (USMP), the lightness value (L*), solubility, emulsification, and gel elasticity were significantly enhanced when treated with 100 W and 300 W ultrasonic-assisted macroporous resin. However, when the ultrasonic power was increased to 500 W, the L* value, solubility, emulsification, and gel elasticity decreased instead, indicating that lower power (100 W and 300 W) ultrasonic-assisted macroporous resin treatment significantly improved the color and functional properties of SMP. Further research found that ultrasound-assisted macroporous resin treatment changed the secondary and tertiary structures of SMP, transformed β-sheet into α-helix and β-turn through rearrangement, and significantly improved surface hydrophobicity. It shows that ultrasonic-assisted macroporous resin treatment expands the SMP structure and exposes hydrophobic groups, thereby improving the color and functional properties of SMP. This study provides a potential strategy for extracting SMP with light color and good functional properties. It also provides a theoretical basis for the wide application of SMP in food processing.

Emulsion stabilising capacity of sunflower meal depending on fraction protein content and particle size

SummarySunflower meal, as a high protein source, is usually utilised in animal feed, but other means of valorisation of this byproduct should be investigated in order to increase sunflower meal industrial functionality and therefore economic value. High protein content could suggest potential ability to stabilise food emulsions. Current study investigated the influence of sunflower meal protein content and particle size distribution in stabilisation of oil‐in‐water emulsions. Sunflower meal samples were characterised in terms of chemical and amino acid content and FTIR spectroscopy, while in the obtained emulsion samples creaming index, droplet size, droplet size distribution and zeta potential were determined. A relatively equal distribution of hydrophilic/hydrophobic amino acids (46% and 54%, respectively) was determined indicating a strong amphiphilic character of proteins and potentially effective emulsion‐stabilising properties. Further results suggested a positive influence of higher protein content (increasing from 16.78% to 42.56%) on lower creaming index values (lowering values from 84% to 32%, respectively). Protein content and particle size distribution strongly affected emulsion droplets sizes (ranging from 77.32 to 238.61 μm) and zeta potential values. Therefore, the evaluation of the obtained results suggested that high protein sunflower meal can be applied for the stabilisation of oil‐in‐water emulsions.

Development and bioassessment of high nutria-omega 5 cookies through animal modeling.

The food industry generates a diverse range of waste byproducts during fruit processing, which can be repurposed to create functional foods and other valuable commodities. In this particular study, leftover agro-waste from pomegranate juice was valorized to obtain pomegranate seed oil (PSO), while utilizing sunflower oilseed cake to produce sunflower meal protein concentrate (SMPC). These two extracted components were then combined as ingredients to produce High Nutria Omega 5 (HNO5) cookies. To ensure the quality and viability of pomegranate seed oil, a comprehensive set of laboratory analytical procedures were employed to evaluate its characteristics. Subsequently, different ratios of pomegranate seed oil and sunflower meal protein concentrate were utilized to develop the HNO5 cookie products. These cookies underwent thorough sensory, physicochemical, storage, and proximate evaluations as well as efficacy studies to assess their overall nutritional quality and shelf-life properties. As compared to the control feed, the findings of the renal and liver functional tests indicated a favorable effect on ALT, AST, ALP, serum urea, creatinine, albumin, globulins, total proteins, and A/G ratio. The results revealed that PSO and SMPC cookies containing 15% PSO and 15% SMPC exhibited stability in numerous physicochemical and sensory assessments. The punicic acid in HNO5 cookies significantly reduced the effects of starvation in rats and progressively improved several metabolic processes and overall health profiles. Graphical Abstract.

Functional, conformational, topographical, and antioxidative properties of convectively- and freeze-dried sunflower protein and hydrolysate: a comparative investigation

This study focused on the influence of convection (at 40 °C and 50 °C) and freeze drying on functionality, structural properties and antioxidant potential of sunflower meal protein (SPm) and hydrolysate (SPHm). Likened to the respective convectively-dried isolates, lyophilized SPm and SPHm showed higher dispersibility and water binding efficacy, but lower oil binding efficacy (buttressed by surface hydrophobicity results) (p < 0.05). The alterations in sulfhydryl clusters and disulfide bridges due to convection drying (under varied temperatures) implied limited unfolding of SPm and SPHm structure and reduction in intermolecular interactions. Moreover, fluorescent intensity and deconvoluted Fourier transform infrared (FTIR) spectroscopy illustrated that convectively-dried (CD) preparations, considerably CDSPHm, possessed more flexible/movable secondary structures over freeze-dried isolates. Topographical study indicated that dehydrated SPHm-s had irregular small particles with partly destroyed/splitted micropores, suggesting disruption in the noncovalent bonds between SPHm-s molecules. Furthermore, isolates from the freeze drying process, notably lyophilized hydrolysate, showed higher antioxidative (DPPH scavenging, ABTS and reducing power) potential over the convectively-dried samples, supported by the analysis of amino acids composition. The current investigation could help the pharmacological and/or food industry to develop new therapeutic product and/or functional food from lyophilized isolates.

Efficacy of using sunflower meal as an ingredient, and partial fishmeal‐replacer, in practical feed formulated for stinging catfish (Heteropneustes fossilis)

AbstractThis study was conducted to determine the growth performance, body composition, and haematological profile of Heteropneustes fossilis in response to the replacement of fish meal (FM) by sunflower meal (SFM). The experiment was conducted in a completely randomized design (CRD) with five treatments and three replications. The fish (initial average body weight of 2.42 ± 0.01 g) were reared in 15 glass aquaria (40 fish/aquarium) with a 150‐L water capacity. Five isoproteic (35%) diets were prepared by replacing FM protein with SFM protein at a rate of 0% (T0), 10% (T10), 20% (T20), 30% (T30), and 40% (T40). Fish were fed with experimental diet twice a day (9.00 and 16.00), 7 days a week for 8 weeks. Fish were sampled at the end of the experimental period of 8 weeks. At the end of the rearing period, the highest weight gain (6.25 ± 0.11g), % weight gain (163.32%), and specific growth rate (1.61 ± 0.03%/day) were observed in the control (T0) treatment, but the difference was not significant (p &gt; 0.05) with T10 and T20 treatments. However, all the growth factors were decreased with the further inclusion level of SFM in replacement of FM, and the lowest growth performance was observed in T40 treatment. The protein efficiency ratio (PER) and feed conversion ratio (FCR) followed the same pattern as the growth parameters. It was found that the whole‐body proximate composition of fish was also affected significantly (p &lt; 0.05). Haematological parameters significantly (P &lt; 0.05) altered at 30% and 40% levels of replacement of FM with SFM. Based on these results, it can be concluded that 20% FM protein can be substituted with SFM protein in the diet of H. fossilis without compromising growth performance, feed utilization, chemical composition, and haematological status. However, according to polynomial regression analysis, the optimum level of replacement of FM protein with SFM protein was determined to be 14.3% in the diet of H. fossilis.

Effect of pectin and temperature on sunflower meal colloidal particles for emulsion structure and stabilisation

SummaryThis study evaluated the formation and dispersion effects with 4% w/w total biopolymer [sunflower meal protein (SMP) and pectin (P)] at SMP:P ratio 1:0, 25:1, 15:1, 5:1, pH 3.7, prepared at room temperature (RT) or heat treated (HT) at 98 °C on emulsion stabilisation. At RT, increasing P concentration increased apparent viscosity and gel‐like behaviour of biopolymer dispersions and emulsions. At SMP:P‐RT ratio 5:1, the dispersion structure showed protein attached to pectin and individual pectin dispersed in the continuous phase. Under this condition, the emulsion presented stability regarding creaming, flocculation and/or coalescence. Whereas when HT, all samples showed low apparent viscosity, but at SMP:P ratio 25:1 and 15:1 emulsions exhibit gel‐like behaviour. However, SMP:P ratio 5:1 dispersion presented spheroid particles and emulsion behaved as liquid‐like material with lower creaming, flocculation and/or coalescence. Therefore, depending on the process parameters, sunflower meal may be used as an ingredient to obtain different food emulsion structure.

Inclusion of Azolla pinnata as an unconventional feed of Zaraibi dairy goats, and effects on milk production and offspring performance.

This study investigated the effects of using sun-dried Azolla (Azolla pinnata) meal (SDAM) protein to replace sunflower meal protein in the diets of Zaraibi goats dams on nutrient digestibility, milk yield, composition, and economics. A total of 15 Zaraibi goats (32.23 ± 0.2 kg) were randomly divided into three equal groups, R1, R2, and R3 which were fed based on average milk production. The basal ration was a concentrated feed mixture containing 0, 10, and 20% SDAM which replaced 0, 25, and 50% of sunflower meal protein in the respective groups. Nutrient digestibility and feeding values were improved with R3 goats, which had the highest level of azolla (20%) R3 versus R2 and R1 goats. The total volatile fatty acid (TVFA) concentration in the in-rumen liquor was elevated by increasing the level of azolla up to 20% in R3 goats. The results revealed significantly higher (P<0.05) mean milk yield in the SDAM groups in comparison to R1 (1184, 1131 and 1034 respectively). The beneficial effects of the tested groups were observed in milk composition, milk fat, milk protein, and non- fats solids. Whereas the milk fat yield was higher in the SDAM group in comparison with the control group (40.84, 37.20, and 33.92). Ration inclusion of SDAM improved economic feed efficiency (relative feed cost and relative daily profit) and had a significant effect on the yield of milk constituents. In general, using up to a level of 20% SDAM in place of sunflower meal for feeding lactating Zaraibi goats improved milk production, milk fat yield, and cost-benefit ratio. This study recommended that, inclusion of sun-dried azolla meal up to 20%, as an unconventional feed for Zaraibi dairy goats and offspring, improved milk production and economically feed efficiency.

Impact of Sunflower Meal Protein Isolate Supplementation on Pasta Quality

Globally, there is an increased demand for plant- and animal-derived proteins. However, animal-derived proteins are still expensive and expected to negatively impact the environment. Sunflower seeds, an excellent source of proteins, are one of the most critical oilseeds produced in the world markets. This study used sunflower meal protein isolate (SMPI), wheat flour (WF), and their blends to make pasta with good sensory features and higher nutritional value. The chemical and amino acid compositions, rheological properties, color attributes, cooking quality, sensory properties, and texture analysis of pasta were evaluated. SMPI showed a high protein content (87.12%) compared to WF (10.90%). The pasta was made from WF with supplementing SMPI at three concentrations (3.0, 6.0, and 9.0% w/w) to improve the nutritional quality. Farinograph parameters showed that water absorption, arrival time, dough development time, mixing tolerance index, dough weakening, and dough stability increased as the percentage of SMPI in the blends increased. The results also showed that the color (L*, a*, and b*) of pasta samples was darker as the mixing level of SMPI increased. The obtained sensorial results confirmed this result. The cooking quality of pasta revealed that the weight, volume, and cooking loss of prepared pasta with SMPI (3.0–9.0%) increased compared to the control sample (pasta with 100% WF). Moreover, sensory evaluation of pasta revealed that all samples were acceptable. Nonetheless, mouth feel and overall acceptability of pasta reinforced with 3.0 and 6.0% SMPI did not notably impact the pasta compared to the control sample, while flavor did not significantly influence the pasta with 3.0% SMPI. These findings demonstrated that pasta supplemented with SMPI could benefit the pasta industry, which requires a suitable technological process to obtain novel products.

Development of protease nanobiocatalysts and their application in hydrolysis of sunflower meal protein isolate

SummaryIn this study, the suitability of fumed silica nanoparticles (FNS) and its derivatives (amino‐modified FNS (AFNS), cyanuric chloride‐activated AFNS (CCAFNS) and epoxy‐modified FNS (GFNS)), for covalent immobilisation of two commercial protease preparations Alcalase® and Flavourzyme® was investigated. The highest hydrolytic activities of immobilised preparations were 25 IU g−1 support (Alcalase‐GFNS) and 2.95 IU g−1 support (Flavourzyme‐CCAFNS). Furthermore, the immobilised preparations showed 43% and 20% of initial specific activities of commercial protease preparations, respectively. Flavourzyme‐CCAFNS also exhibited the highest exopeptidase activity of 22.83 L‐pNAU g−1 support. Finally, these two nanobiocatalysts were successfully applied for hydrolysis of sunflower meal protein isolate (SMPI), providing two times higher hydrolysis yields in comparison to free enzymes, justifying the applied immobilisation process. Namely, the highest hydrolysis yield (30%) was gained by the sequential hydrolysis with Alcalase‐GFNS and Flavourzyme‐CCAFNS, which resulted in the formation of small hydrophobic and hydrophilic peptides, ≤5 kDa, confirmed by HPLC analysis and electrophoretic separation.

Sunflower meal as an alternative protein source to replace soybean meal in the diet of GIFT strain of Nile tilapia Oreochromis niloticus

The main objective of the study was to investigate the effect of partial replacement of soybean meal (SBM) protein with sunflower meal (SFM) protein on growth performance, feed utilisation, survival and body composition of GIFT tilapia. Fish weighing between 1.03±0.01 and 1.19±0.02 g were stocked in in plastic troughs (50 l) at a stocking rate of 15 fishes per trough. Percent replacement of SBM by SFM on the basis of crude protein was 0% (control), 10% (SFM10), 20% (SFM20) and 30% (SFM30). Diets were fed to fish at the rate of 5% of the total fish biomass, daily for a period of 60 days. Fish fed with SFM 20% and SFM 30% sunflower meal had best performance in terms of weight gain, specific growth rate, protein efficiency ratio, feed efficiency ratio and feed conversion ratio (p&lt;0.05). Analysis of fish whole body composition revealed that with increasing dietary SFM levels, whole body protein, ash and moisture contents showed significant difference among dietary treatments (p&lt;0.05). Fish fed with SFM 30 diet showed the best growth performance compared to fish fed with the control diet.

Proteolysis kinetics and structural characterization of ultrasonic pretreated sunflower protein

Proteolysis kinetics and structure attributes of sunflower meal protein (SMP) pretreated using sonication of frequency type single (20, 40 kHz) and dual (20/40 kHz) were examined. A simplified model with impeded enzyme reaction was developed and the proteolysis of SMP in a heterogeneous system was successfully described. Initial observed rate (kin) increased after sonication, demonstrating the impacts of sonication on SMP by enhancing proteolysis (enzymolysis) and altering the structure of SMP, which was validated by circular dichroism (CD) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy and sodium dodecyl sulfide polyacrylamide gel electrophoresis (SDS-PAGE) analyses. From SMP characterization, there was a reduction in α-helix, enhancement in absorption intensity and alterations in functional groups of SMP following sonication. SEM and AFM observations indicated that sonicated SMP unfolded and exhibited more heterogenous structures, and irregular small-sized particles than control, especially at 20/40 kHz. SDS-PAGE profile displayed notable changes in molecular weight after sonication, which evidenced limited unfolding in SMP conformation. The kinetic model has possibility of being used to control enzymolysis; and structural attributes could guide in the development of ultrasonic equipment for use of pretreating protein for enzymolysis.

Ultrasound pretreatment of sunflower protein: Impact on enzymolysis, ACE‐inhibition activity, and structure characterization

Impacts of dual-frequency ultrasonic (DFU) with various operating modes (simultaneous and sequential modes) on degree of hydrolysis (DH) and conversion rate (CR) of sunflower meal protein (SMP) and activity of ACE-inhibition of SMP hydrolysates were examined. Results revealed that sequential and simultaneous modes enhanced DH by 7.73% and 11.22%, and CR by 26.23% and 26.98% of SMP (p < .05). Additionally, the maximal ACE-inhibition activity obtained at 75 min of enzymolysis was 64.46% for sonicated SMP hydrolysate (simultaneous mode), which was 32.52% higher than the control. Alterations in surface hydrophobicity, UV-Vis spectra, and intrinsic fluorescence indicated unfolding of SMP. AFM showed that sonication decreased the particles size and altered the structure of SMP. Amino acids composition demonstrated that both DFU modes pretreatments could improve the hydrophobic amino acids. Consequently, sonication enhanced DH, CR of SMP, and the activity of ACE-inhibition of hydrolysates confirmed by changes in SMP structure. Practical applications Sunflower protein, an extract from sunflower meal, is a potential source for preparing the bioactive compounds such as ACE- inhibition peptides. These peptides are safe, easy to absorb and stable, and have certain benefits for patients. Sonication with different operating frequency modes were applied to enhance enzymolysis of sunflower protein and ACE-inhibition activity of its hydrolysates. Sonication was displayed to be an operative technique to yield hydrolysates with good ACE-inhibition activity confirmed by monitoring the alterations in sunflower protein structure. Thus, sonication pretreatment of sunflower protein maybe practicable in the enzymolysis and the activity of ACE-inhibition in industry.

Localized enzymolysis and sonochemically modified sunflower protein: Physical, functional and structure attributes.

Impacts of localized enzymolysis and sonication on physical, techno-functional, and structure attributes of sunflower meal protein (SMP) and its hydrolysate (SMPH) were studied. SMP was subjected to enzymolysis (using alcalase) to prepare SMPH with various degrees of hydrolysis (6-24% DH). Enzymolysis decreased colour lightness, turbidity, and particle size of unsonicated and sonicated SMP, while it increased the absolute values of zeta potential (P<0.05). Sonication improved oil absorption capacity and dispersibility over unsonicated samples. Contrarily, sonicated preparations showed a decrease in water holding capacity. Intrinsic fluorescence and FTIR spectral analyses suggested that SMPH had more movable/flexible secondary structures than SMP. Moreover, the changes in sulfhydryl clusters and disulfide linkages following sonication demonstrated limited unfolding of SMP and SMPH structure and decrease in intermolecular interactions. SDS-PAGE profile exhibited significant reduction in molecular weight (MW) of sonicated SMP, whereas did not display differences between unsonicated and sonicated SMPH. From further MW analysis, SMPH was categorized with high proportion of small-sized peptides≤3kDa fractions, which increased from 78.64 to 93.01% (control) and from 82.3 to 93.88% (sonication) with enzymolysis (6-24DH). Localized enzymolysis and sonication can be utilised to modify the physical and conformational attributes of SMP and SMPH, which could enhance their functionalities and broaden the utilisation area in food industry.

PSIII-38 Pepsin-pancreatin protein digestibility of various protein sources intended for pet food

Abstract Pet food companies need quality protein ingredients to offer new and different options for pet owners. Evaluating these proteins with animal feeding trials are time consuming and expensive. An in vitro (benchtop) method could provide detailed information about protein quality for novel ingredients. Therefore, the objective of this experiment was to develop a pepsin-pancreatin digestibility assay and determine the appropriate incubation time for enzyme hydrolysis to approximate results from animal studies. Ingredients evaluated were faba beans, navy beans, spray-dried granulated egg, chick pea, pea protein concentrate (72% CP and 50% CP), green field peas, and sunflower meal. One gram of test ingredient was mixed with an HCl-pepsin solution and then incubated for 3 or 6 hours at 37°C before NaOH was added, stopping the pepsin reaction. Phosphate buffer with pancreatin was then added and the tubes were incubated for an additional 18 hours. Samples were then centrifuged, washed, filtered, and dried at 105°C overnight. Residual protein was determined with a modified Kjeldahl assay and was used to calculate protein digestibility. Data were analyzed using the GLIMMIX procedure for mixed models (SAS v 9.4, SAS Institute Inc, Cary, NC). There was no interaction between test ingredient and time (P = 0.63). Incubation time did not influence protein digestibility (P = 0.69). Test ingredient did impact protein digestibility. Spray-dried granulated egg, faba bean, green field pea, and pea protein concentrate (50% CP) did not differ with digestibilities above 97% (P &amp;lt; 0.0001). Navy bean had a digestibility of 93%. The lowest digestibilities were sunflower meal and pea protein concentrate (72% CP). Overall, the crude protein digestibility was higher than expected. This data would suggest other factors, such as the amount and activity of the enzyme used, should be altered to obtain digestibility values that are consistent with reported values from animal studies.

Effects of Feeding Rumen-Protected Sunflower Seed and Meal Protein on Feed Intake, Diet Digestibility, Ruminal, Cecal Fermentation, and Growth Performance of Lambs.

Simple SummaryDue to inefficient use of nitrogen (N) in rumen, ruminants have a low efficiency of N utilization. A large part of ingested N is excreted into the environment without being used by animals. The objective of this study was to analyze the efficacy of a treatment combining malic acid and heating (MAH) to protect the protein in sunflower seeds (SS) and meal (SM) against rumen degradation and to improve the growth of lambs. Two high-cereal concentrates, either including untreated or MAH-treated SS and SM, were fed to two homogeneous groups of lambs. Further, feed intake, diet digestibility, and lamb growth from 14 to 26 kg body weight were assessed. An in vitro trial indicated that the MAH-treatment modified the rumen fermentation pattern of both SS and SM, and it reduced the NH3-N concentrations for SM. However, there were no significant effects of the MAH-treatment on feed intake, diet digestibility or growth of lambs. The hot carcasses of the lambs fed the MAH-treated concentrate were 7.9% heavier but not statistically different to those of the untreated group. In conclusion, under the conditions of the present study the MAH treatment did not improve the growth performance of lambs.The objective of this study was to analyze the efficacy of a treatment (MAH) of sunflower seed (SS) and meal (SM) with a malic acid solution (1 M; 400 mL/kg) and heating (150 °C, 2 h) to protect protein against rumen degradation and to improve the growth of lambs. Two homogeneous groups of 12 Lacaune lambs each (14.2 ± 0.35 kg body weight) were fed either a concentrate including untreated SS and SM or a concentrate with MAH-treated SS and SM. Lambs were fed concentrate and barley straw ad libitum for 40 days (about 26 kg body weight); feed intake and growth of lambs were recorded; blood samples were taken on days 0, 20, and the slaughter day for analysis of urea-N and amino acid-N; diet digestibility was determined; and ruminal and cecal samples were collected after slaughter. The in vitro incubation of both concentrates with sheep ruminal fluid for 12 h showed that the MAH-treatment tended to reduce NH3-N concentrations and increased propionate production. However, there were no differences (p > 0.05) between groups in any of the tested variables in the in vivo trial.

Changes in functionalities, conformational characteristics and antioxidative capacities of sunflower protein by controlled enzymolysis and ultrasonication action.

Functionalities, conformational characteristics and antioxidative capacities of sunflower meal protein isolate (SMPI) and its hydrolysates (SMPIH) at various degree of hydrolysis (DH) (6, 12, 18, 24%) were investigated following sonication. Enzymolysis notably enhanced the solubility, foaming properties and emulsion stability index (ESI) of untreated and sonicated SMPI at most examined pH. Nonetheless, emulsion activity index (EAI) of SMPI were more than SMPIH at all pH values, especially at pH 4.0-10.0 (P < 0.05). Compared with control, sonication improved solubility, foaming capacity and emulsification properties, but decreased foaming stability and had significant influence on the SMPI and SMPIH structure. Furthermore, sonication efficaciously enhanced reducing power and superoxide, and ABTS radical scavenging capacity of all preparations (P < 0.05) over control, confirmed by the analyses of hydrophobicities and content of amino acid compositions. Finally, our investigation suggests that sonicated SMPIH can create new opportunities for developing natural additives for different cosmetic, food and pharmacological preparations.

A novel approach to determine optimal protein texturization conditions - A critical moisture level with increased effect of temperature on viscosity reduction in the rubbery state

The effect of moisture on reduction of the flow starting temperature (Tf; i.e. start of flow through a capillary die at constant pressure conditions) in major protein ingredients used in fish feed has been assessed using a Phase Transition Analyzer. All proteins showed an initial linear reduction in Tf followed by a sharp sigmoidal reduction at higher moisture content. A critical moisture level (Mcr) could be defined at the onset of this transition region. Fishmeal and wheat gluten show the lowest Mcr (138 and 160 g kg-1, respectively) and highest reduction in Tf above Mcr. Sunflower meal and soy protein concentrate demand more moisture, show higher variability in Mcr (210–262 and 233–306 g kg-1, respectively) and less reduction in Tf at moisture levels above Mcr. The Tf level corresponds to an apparent viscosity of 105 Pa s and can be combined with the William-Landel-Ferry equation to establish moisture contour plots for the effect of temperature on viscosity reduction in the rubbery state. The protein specific Mcr levels and rheological profiles can be applied to determine optimal moisture and temperature conditions for plasticization and texturization of extruded food and feed products.

Antioxidant activities of sunflower protein hydrolysates treated with dual‐frequency ultrasonic: Optimization study

AbstractIn this study, ultrasound pretreatments of sunflower‐meal protein (SMP) to yield high antioxidant capacity from its hydrolysates by response surface methodology were optimized. Optimization of experimental conditions was achieved to examine the impact of temperature, solvent‐solid ratio and sonication time on antioxidant capacities of SMP hydrolysates with Box–Behnken's design. Quadratic models of DPPH‐scavenging activity (DPPHSA), hydroxyl‐radical scavenging activity (HRSA), and Cu2+ and Fe2+ chelating activity (Cu2+‐CA and Fe2+‐CA) were developed, and their coefficients observed from multiple‐regression analysis. ANOVA indicated that time was highly significant (p &lt; .01) on all experimental responses. The best experimental point of DPPHSA, HRSA, Cu2+‐CA, and Fe2+‐CA was accessed at 42.50°C, 18.16 mL/g and 26.52 min and the predicted data for these responses were 52.09, 70.05, 50.85, and 43.35%, respectively. Outcome of verification experiment was reliable with predicted data for all responses. Additionally, DPPHSA, HRSA, Cu2+‐CA, and Fe2+‐CA of pretreated hydrolysate improved (p &lt; .05) by 17.41, 20.00, 14.72, and 26.41%, respectively over nonsonicated hydrolysate. Amino acid content and hydrophobicity of SMP hydrolysate at the optimum sonication condition were analyzed. Analyses indicated that ultrasonication could facilitate the releasing/unfolding of hydrophobic amino acids from SMP over nonsonicated samples during enzymolysis with high antioxidative capacity.Practical applicationsSonication pretreatment has been presented to have notable impacts on the antioxidant's capacities of protein hydrolysates. Sunflower‐meal protein is an abundant and low‐cost residue of oil industries, and is considered a potential bioactive peptides source, such as antioxidants. In this research, sonication pretreatment has been illustrated to be an effectual technique for the production of hydrolysates with antioxidant capacity from SMP. So, optimization of ultrasonication conditions is vital to examine the antioxidant capacities in SMP hydrolysates, which could be applied in large‐scale food system and future pharmaceutical activity research.