Emulsion Stability Index Research Articles

Protocatechuic acid and gallic acid improve the emulsion and thermal stability of whey protein by covalent binding

This study aimed to explore the impacts of gallic acid (GA)/protocatechuic acid (PA) on the structural and functional characteristics of whey proteins (WP) through covalent binding. To this purpose, the covalent complexes of WP-PA and WP-GA at different concentration gradients were prepared by the alkaline method. SDS-PAGE indicated that PA/GA was cross-linked by covalent bonds. The decreased contents of free amino and sulfhydryl groups suggested that WP formed covalent bonds with PA/GA by amino and sulfhydryl groups, and the structure of WP became slightly looser after covalent modification by PA/GA. When the concentration of GA was added up to 10 mM, the structure of WP was slightly loosened with a reduction of α-helix content by 2.3% and an increase in random coil content by 3.0%. The emulsion stability index of WP increased by 14.9 min after interaction with GA. Moreover, the binding of WP and 2–10 mM PA/GA increased the denaturation temperature by 1.95 to 19.87 °C, indicating the improved thermal stability of the PA/GA-WP covalent complex. Additionally, the antioxidant capacity of WP was increased with increasing GA/PA concentration. This work may offer worthful information for enhancing the functional properties of WP and the application of the PA/GA-WP covalent complexes in food emulsifiers.

Extraction, purification and characterization of an arabinogalactan from frost (riverbank) grape (Vitis riparia Michx.) stems

This study investigated the extraction and properties of an arabinogalactan polysaccharide from frost grape (FGP) as a potential alternative to gum arabic (GA). Collection date, solvent:feed ratio (S:F), chip size, C-18 filtration, ultrafiltration, freeze drying versus spray drying, methanol pre-extraction, and water absorption were examined. Sugar composition, elemental analysis, dietary fiber content, emulsification activity index (EAI), emulsification stability index (ESI), and viscosity were used to evaluate the extracts. Exudates collected in March from live stems were viscous with high percentage solids and FGP, while May collections were watery with low percentage solids and FGP. Frost grape stems were collected, chipped, and classified by size. The extraction system utilized pressure or vacuum to increase contact between the chips and extraction water. A S:F ratio of ca. 24% gave an excellent yield of FGP. Chips between 1.8 and 3.8 mm gave the highest mass yields. Pre-extracting the chips with methanol and C-18 filtration of the water extract both yielded a lighter product. The EAI for the FGP was higher than that for GA; however, its ESI was lower. Ultrafiltration of the crude extract separated glucose, fructose, and sucrose from the FGP. FGP with glucose, fructose, and sucrose adsorbed water and became darker.

Effects of multi-frequency ultrasound on sodium caseinate/pectin complex: Emulsifying properties, interaction force, structure and correlation

This study aimed to improve the emulsification properties of the sodium caseinate (Cas) and pectin (Pec) complex using multi-frequency power ultrasound to regulate the complexation of Cas and Pec. The results revealed that optimal ultrasonic treatment (Frequency 60 kHz, power density 50 W/L, and time 25 min) led to a 33.12 % increase in emulsifying activity (EAI) and a 7.27 % increase in emulsifying stability index (ESI) of the Cas-Pec complex. Our results demonstrated that electrostatic interactions and hydrogen bonds were the main driving forces for complex formation, and these were reinforced by ultrasound treatment. Moreover, it was observed that ultrasonic treatment improved the surface hydrophobicity, thermal stability, and secondary structure of the complex. Scanning electron microscopy and atomic force microscopy analyses revealed that the ultrasonically prepared Cas-Pec complex had a dense, uniform spherical structure with reduced surface roughness. It was further confirmed that the complex's emulsification properties were highly correlated with its physicochemical and structural properties. Multi-frequency ultrasound changes the interaction by regulating protein structure and ultimately acting on the interfacial adsorption behavior of the complex. This work contributes to expanding the role of multi-frequency ultrasound in modifying the emulsification properties of the complex.

Physicochemical Properties and Characterization of a New Product: Spray Dried Hempseed Milk.

The objective of the present study was to investigate the physicochemical properties and powder characterization of hempseed milk powders obtained by whole hempseed and cold-pressed whole hempseed paste (de-oiled). Whole hempseed and de-oiled hempseed paste were used to produce plant based milk powder applying spray drying process. The influence of oil content on physicochemical features, emulsion and rheological properties of the powders was examined. Results showed that dry content, total protein, loose density, tapped density, viscosity, foaming capacity and foaming stability of sprayed-powders produced in milk obtained using whole and de-oiled hemp seeds were not statistically different from each other (p > 0.05). By using de-oiled hempseed cake in feed solution preparation, spray dryer process efficiency increased from 31 to 44% without using any carrier agents. Hempseed powder product with improved properties such as apparent density, solubility, hygroscopicity and emulsion stability index was obtained.

Products and Properties of Components from Heat-Denatured Peanut Meal Following Solid-State Fermentation by Aspergillus oryzae and Saccharomyces cerevisiae

In heat-denatured peanut meal (HDPM), proteins are denatured and polysaccharides are degraded and browned. It can only be used as feed or fertilizer, and not using it as such is a waste of resources. To achieve high-value HDPM use, solid-state fermentation by Aspergillus oryzae and Saccharomyces cerevisiae was investigated. Conditions were optimized by response surface methodology and high-value antioxidant peptides (APs), nonstarch polysaccharides (NSPs), and fermentation products of heat-denatured peanut meal (FHDPM) were obtained. Optimal culture conditions were strain ratio 6:5, inoculation volume 2 mL, and fermentation for 42 h at 35 °C. Under optimal conditions, the theoretical soluble nitrogen concentration, 1,1-Diphenyl-2-picrylhydrazyl radical scavenging rate, hydroxyl free radical scavenging rate, and NSP yield reached 44.78 mg/mL, 62.44%, 94.95%, and 3.73%, respectively; however, their experimental values were 46.80 ± 1.23 mg/mL, 72.18 ± 0.78%, 96.79 ± 0.55%, and 4.42 ± 0.21%, respectively. NSPs, Aps, and FHDPM exhibited four higher classes and eight types of antioxidant activities. Moreover, levels of amino acids and trace elements, and physicochemical properties including emulsion activity index, emulsion stability index, foam capacity, foam stability, water holding capacity, and oil absorption capacity were enhanced by fermentation. The results indicate that APs and NSPs could serve as promising natural antioxidants in the food industry, and FHDPM could be used as a new type of high-value nutritional product in the feed industry. The findings provide new insight for comprehensive processing and utilization of HDPM.

Influence of environmental pH on the interaction properties of WP-EGCG non-covalent nanocomplexes.

Whey protein-epigallocatechin gallate (WP-EGCG) covalent conjugates and non-covalent nanocomplexes were prepared and compared using Fourier-transform infrared spectra. The effect of pH (at 2.6, 6.2, 7.1, and 8.2) on the non-covalent nanocomplexes' functional properties and the WP-EGCG interactions were investigated by studying antioxidant activity, emulsification, fluorescence quenching, and molecular docking, respectively. With the formation of non-covalent and covalent complexes, the amide band decreased; the -OH peak disappeared; the antioxidant activity of WP-EGCG non-covalent complexes was 2.59- and 2.61-times stronger than WP-EGCG covalent conjugates for 1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric reducing ability of plasma(FRAP), respectively (particle size: 137 versus 370 nm). The antioxidant activity (DPPH 27.48-44.32%, FRAP 0.47-0.63) was stronger at pH 6.2-7.1 than at pH 2.6 and pH 8.2 (DPPH 19.50% and 26.36%, FRAP 0.39 and 0.41). Emulsification was highest (emulsifying activity index 181 m2 g-1 , emulsifying stability index 107%) at pH 7.1. The interaction between whey protein (WP) and EGCG was stronger under neutral and weakly acidic conditions: KSV (5.11-8.95 × 102 L mol-1 ) and Kq (5.11-8.95 × 1010 L mol s-1 ) at pH 6.2-7.1. Binding constants (pH 6.2 and pH 7.1) increased with increasing temperature. Molecular docking suggested that hydrophobic interactions played key roles at pH 6.2 and pH 7.1 (∆H > 0, ∆S > 0). Hydrogen bonding was the dominant force at pH 2.6 and pH 8.2 (∆H < 0, ∆S < 0). Environmental pH impacted the binding forces of WP-EGCG nanocomplexes. The interaction between WP and EGCG was stronger under neutral and weakly acidic conditions. Neutral and weakly acidic conditions are preferable for WP-EGCG non-covalent nanocomplex formation. © 2023 Society of Chemical Industry.

Ultrasonic-assisted glycosylation with κ-carrageenan on the functional and structural properties of fish gelatin.

Fish gelatin (FG) has multifunctional properties similar to mammalian gelatin (MG), and it has been recognized as the optimal alternative to MG. While its poor surface-active and gelling properties significantly limit its application values, glycosylation has been successfully used to increase surface-active properties of FG, but the influence of ultrasonic-associated glycosylation (UAG) on the gelling and structural characteristics of FG is still rarely reported. This article explores UAG (100-200 W, 0.5-1 h) with κ-carrageenan (κC) on the functional properties (emulsifying, gelling and rheological properties) and structural characteristics of FG. The longer time and higher power of ultrasonics accelerated the glycosylation reaction with an increase in glycosylation degree and browning index values. Compared with original FG, FG-κC mixture and bovine gelatin, UAG-modified FG possessed higher emulsification activity index, emulsion stability index, gel strength, hardness and melting temperature values. Among them, gelatin modified by appropriate ultrasonic conditions (200 W, 0.5 h) had the highest emulsifying and gelling properties. Rheological results showed that UAG contributed to the gelation process of gelatin with advanced gelation time and endowed it with high viscosity. Structural analysis indicated that UAG promoted κC to link with FG by the formation of covalent and hydrogen bonds, restricting more bound and immobilized water in the gels, exhibiting higher gelling properties. This work showed that UAG with κC is a promising method to produce high gelling and emulsifying properties of FG that could replace MG. © 2023 Society of Chemical Industry.

Emulsion stability prediction tool

Produced fluids from oil field often contain emulsions which are a major challenge in the Petroleum Industry. Emulsion stability determines the ease with which oil and water separate in emulsion and plays an important role for production operations. The standard approach to know emulsion strength involves bottle testing which is time consuming and subject to human interpretation. A faster and safer alternative is by running a mathematical model. However, because of the complexity of emulsion system, an equation from first principles for predicting emulsion stability is not available even with such vast work in the literature. In this research we test a data driven approach for predicting emulsion stability category and introduce a new concept of emulsion stability index. A model is built from the emulsion behavior of real crude oil and validated for field success. A software application of this produced emulsion stability tool, packaged as PrEST, is also created for deploying the model at enterprise level to provide quick guideline for emulsion strength.

Physicochemical and structural characterization of whey protein concentrate-tomato pectin conjugates.

Protein-pectin conjugates, obtained through a controlled Maillard reaction in blends of precursors, are studied for their contribution to improving the emulsifying and thermal properties of proteins. The objective was to obtain a conjugate between whey protein concentrate (WPC) and non-conventional pectins extracted in acid (acid tomato pectin, ATP) and aqueous medium (water tomato pectin, WTP) from industrialized tomato residues (tomato waste, TW), characterize the conjugates and study their emulsion properties. The Maillard reaction was carried out at 60 °C and 75% relative humidity in blends with 2:1 proportions; 1:1 and 1:2 (mprotein :mpectin ) for 3, 6 and 12 days. Conjugates were compared concerning treated and untreated WPC. The WPC-ATP conjugate showed significant increases in color difference (ΔE). The electrophoresis profile of the conjugates showed diffuse bands of molecular weight between 37 and 250 kDa and a reduction in the intensity of bands characteristic of WPC (α-lactalbumin and β-lactoglobulin). Thermal analysis showed an increase in the peak temperature and a reduction in the enthalpy change in protein denaturation, associated with the formation of conjugates. The infrared spectroscopy of the conjugates, in the amide III zone (1300-1100 cm-1 ), indicated an increase in the relative peak area associated with the unfolding and exhibition of the hydrophobic zones of the WPC fraction. The emulsions formulated with the conjugates showed a significant increase in the emulsifying stability index (ESI) (P < 0.05) concerning the treated and untreated WPC emulsions. The formation of conjugates increased the emulsifying properties and improved the thermal stability of WPC, showing an innovative and alternative food ingredient too. © 2023 Society of Chemical Industry.

PAMUK ÇEKİRDEĞİ PROTEİN KONSANTRESİNİN KARAKTERİSTİK ÖZELLİKLERİNİN BELİRLENMESİ

The current study focused on characteristic attributes of protein concentrate obtained from oil-free cottonseed. For this, the physicochemical properties namely moisture content, water activity, color, flowability, wettability, and protein solubility of cottonseed protein concentrate (CSPC) were investigated. Water holding capacity (WHC), oil binding capacity (OBC), foaming capacity, foam stability (10 and 30 min), emulsion activity index (EAI) and emulsion stability index (ESI) (10 and 30 min) of proteins were 2.75 g water/g protein, 2.59 g oil/g protein, 29.00%, 93.10% - 69.05%, 6.25 m2/g and 29.27-87.81 min, respectively. Bands regarding CSPC in the 45 kDa molecular weight were detected by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) patterns. Fourier-transform infrared spectroscopy (FTIR) was used to verify the protein-specific structures. Sheet structures in the surface morphology of CSPC were dominant when scanning electron microscopy (SEM) images were investigated. Thermal gravimetric analyzer (TGA) results showed that the protein concentrate exhibited excellent stability to temperature.

Pickering Emulsion Stabilized by Fish Myofibrillar Proteins Modified with Tannic Acid, as Influenced by Different Drying Methods

A novel food-grade, particles-based Pickering emulsion (PE) was prepared from a marine source. Yellow stripe trevally is an under-utilized species. The use of its muscle protein as solid food-grade particles for the preparation of a Pickering emulsion can be a potential means of obtaining the natural nutritive emulsifier/stabilizer. Fish myofibrillar proteins (FMP) were modified with tannic acid (TA) at varying concentrations (0.125, 0.25, and 0.5%) followed by freeze-drying (FD) or spray-drying (SD). Physicochemical characteristics and emulsifying properties of obtained FMP-TA complexed particles were assessed for structural changes and oil-in-water emulsion stabilization. The addition of TA caused a reduction in surface hydrophobicity and total sulfhydryl content values for either FD-FMP or SD-FMP. Conversely, disulfide bond content was significantly increased, particularly when TA at 0.5% was used (p < 0.05). FTIR, spectrofluorometer, and the protein pattern also confirmed the cross-linking between FMP and TA. SD-FMP modified with 0.5% TA (SD-FMP-0.5TA) rendered the highest emulsifying stability index but had a lowered emulsifying activity index (p < 0.05). Confocal microscopic images, droplet size, and rheological properties revealed that a SD-FMP-0.5TA-stabilized emulsion had higher stability after 45 days of storage than an FD-FMP-0.5TA-stabilized emulsion. Therefore, the SD-FMP-0.5TA complex could be used as a potential food-grade stabilizer/emulsifier for PE with enhanced emulsifying properties.

Physico-Chemical Study of Curcumin and Its Application in O/W/O Multiple Emulsion.

Curcuma is a world-renowned herb known for its immense health benefits. In this study, physicochemical analyses were performed on the curcumin standard sample and curcumin multiple emulsions. The emulsions were analysed for thermal and structural stability for 21 days. Confocal laser microscopy (CLSM) was performed in order to observe the emulsion encapsulation. Modulated differential scanning calorimetry (MDSC) and HPLC methods revealed a variety of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin, and cyclocurcumin) in the investigated curcumin standard. In addition, the MDSC method was found to be suitable and comparable to HPLC for determining the curcuminoid substances. The analysis of the curcumin release revealed a value of 0.18 w.% after 14 days as the equilibrium value. Furthermore, an increase in the sizes of the emulsions was observed at the end of the 21-day study. The emulsion stability index (ESI) was used to measure the stability of multiple emulsions. The ESI reached 55.8% between 7 and 21 days later. Nano droplets of the oil phase loaded with dispersed curcumin particles captured inside the water-based carboxymethylcellulose micelles were clearly observed by CLSM.

The role of β-subunit in emulsifying performance of β-conglycinin

The most crucial protein that affects the ability of soybean protein to emulsify is β-conglycinin. The subunit composition of β-conglycinin is one of the important factors affecting its emulsification performance. In order to investigate the effect of β-subunit of β-conglycinin on its emulsifying property, the separated and purified β-subunit was added to β-conglycinin in different proportions, and the properties of the β-conglycinin before and after emulsification were measured. The β-subunit appeared to improve the stability of the β-conglycinin in the aqueous dispersion as evidenced by the average particle size significantly decreasing, the surface hydrophobicity significantly increasing, and the Emulsification activity index and Emulsion stability index further improving. The secondary structure of β-conglycinin was altered by the addition of β-subunit, which caused more conversion of β-sheet and β-turn to α-helix, increasing the flexibility of protein molecules. Additionally, the particle size distribution, ζ-potential and creaming index of the stable emulsion formed by β-conglycinin were also measured. The results showed that the increase of β-subunit content improved the stability of the emulsion to some extent. The stability of emulsion mainly relies on their internal structure to maintain. It could be concluded from rheological analysis that the viscosity of emulsion increases due to the presence of β-subunits and the existence of weak gel structure inside them, which is corroborated by the results of confocal laser scanning electron microscopy. The elucidation of the influence of subunits on the emulsification characteristics of soyabean protein is beneficial to the development of soybean protein industry.

Sesame seed protein: Amino acid, functional, and physicochemical profiles

Sesame (Sesamum indicum L.) is an erect herbaceous annual plant with flat seeds. It is one of the oldest cultivated oilseed plants in the world, especially popular in Africa and Asia.&#x0D; The present research objective was to describe a sesame protein isolate, i.e., its amino acid profile, functional and physicochemical properties, zeta potential, and hydrodynamic diameter. The surface charge and hydrodynamic diameter in aqueous solutions were obtained for standard sesame seeds, defatted sesame seeds, and the sesame protein isolate.&#x0D; Defatted sesame seeds yielded the following optimal parameters: salt concentration – 0.6 M, pH – 7, iso-electric point (pI) – 4. The sesame protein isolate was rich in methionine content, which is rare in other plant proteins, but its lysine content was lower than in other isolates. The sesame protein isolate displayed almost identical zeta potential profiles with its pH. The decreasing pH increased the zeta values gradually from the lowest negative value to the highest positive value. The zeta potentials of standard and defatted sesame seeds at pH 7 were –23.53 and –17.30, respectively. The hydrodynamic diameter of the sesame protein isolate (0.33 μm) was smaller than that of sesame seeds (2.64 μm) and defatted sesame seeds (3.02 μm). The sesame protein isolate had a water holding capacity of 1.26 g/g and an oil holding capacity of 3.40 g/g. Its emulsifying properties looked as follows: emulsion capacity – 51.32%, emulsion stability – 49.50%, emulsion activity index – 12.86 m2/g, and emulsion stability index – 44.96 min, respectively. These values are suitable for the sesame protein isolate and are consistent with the literature.&#x0D; The sesame protein isolate was a good source of protein (88.98%). Using sesame proteins as functional components can be an important basis for better knowledge of the relationship between electrical charge interactions in food matrices and the structure, stability, shelf life, texture, structural and functional properties of food. Research prospects include the effects of sesame protein isolates on various food systems.

POSS derivatives containing extremely different surface properties as emulsifiers in colloidal systems

The role of functionalized polyhedral oligomeric silsesquioxane (POSS) in emulsion systems is still insufficiently researched. Therefore, this paper presents two aspects. First, the effect of the sequence of olefin introduction and the olefins chemical character on the course and efficiency of hydrosilylation was studied. The use of olefins of drastically different properties was expected to maximally expose their impact on the efficiency of hydrosilylation. The second involve the application of the obtained compounds to be used as emulsifier. Functionalized silsesquioxanes were obtained by subsequent hydrosilylation of spherosilicate with two olefins that is allyl-octafluoropentyl ether and allyl polyether. The hydrosilylation process was monitored by IR spectroscopy in real time. All obtained compounds were used as emulsifiers and the stability of colloidal systems was analyzed using multiple light scattering. Moreover, emulsion stability index over time was also determined. According to the results, both the sequence and the type of introduced substituents have impact on the rate of hydrosilylation. Moreover, it has been shown that the moment of the catalyst addition also influences the character of the process. The results proved that the introduction of fluoroalkyl groups and polyether substituents significantly changed the emulsifying properties of POSS.

Formation of Coconut Oil By–Product Protein Concentrate–Pectin Through Electrostatic Interaction to Improve Emulsifying Properties

Coconut oil has been rising in popularity because of its health benefits. Coconut oil by-product or &lt;em&gt;blondo&lt;/em&gt; is obtained during wet processing for virgin coconut oil production. It has a high protein content and can be utilized as an emulsifier in food products. This research aimed to examine the effect of pH, protein and pectin concentration on the stability and emulsification properties of heat-treated &lt;em&gt;blondo&lt;/em&gt; protein concentrate-pectin complexes. The best conditions of pH, pectin and protein concentration for forming &lt;em&gt;blondo&lt;/em&gt; protein concentrate-pectin complexes through electrostatic interaction were obtained by mixing &lt;em&gt;blondo&lt;/em&gt; protein concentrate solution (0.5 to 1.5 wt%) with pectin (0.1 to 0.35 wt%) at different pH conditions (3 to 5). These particles were tested for emulsifying activity, stability and heat stability (85±2 °C; 15 minutes). Complexes formed using 0.5 wt% protein and 0.35 wt% pectin at pH 4 obtained from these experiments had the best zeta potential value and particle size, respectively -25.88 mV and 192.92 nm. Complexation between protein and pectin enhanced the emulsion activity index (EAI), emulsion stability index (ESI) and protection of self-aggregation protein during heating. Complexes that were formed remain stable across a range of pH values (pH 4 to 7). Thus, &lt;em&gt;blondo&lt;/em&gt; protein concentrate-pectin complexes formed in this research through electrostatic interaction have better functional properties than the &lt;em&gt;blondo&lt;/em&gt; protein concentrate before complexation. Emulsions created using &lt;em&gt;blondo&lt;/em&gt; protein concentrate-pectin complexes through electrostatic interaction also had a higher value of emulsifying activity, stability and heat stability than emulsions with &lt;em&gt;blondo&lt;/em&gt; protein concentrate alone.

Production and features of antioxidative hydrolysate from wild almond protein isolate using ficin immobilised on the layered double hydroxide

SummaryProtein hydrolysates from wild almond protein isolate (WAPI) with different degrees of hydrolysis (DH) were synthesised using free and immobilised ficin on the magnetic layered double hydroxide and characterised. The highest DH values after 3 h of achieving 11.69 ± 0.15 and 11.37 ± 0.12, respectively, and gained hydrolysate were collected for further analysis. The zeta potential for the hydrolysis of free and immobilised ficin over hydrolysing time due to differences in molecular mass distribution decreased. By increasing the hydrolysing time in the case of free and immobilised ficin, the emulsion activity index gradually decreased, whereas the amount of emulsion stability index did not. The immobilised form of ficin‐treated hydrolysate showed a suitable level of DPPH radical scavenging and appeared to be effective in enhancing the oxidative stability of linoleic acid, sunflower oil and O/W emulsion. Thus WAPI hydrolysates that were treated with immobilised ficin could serve as an alternative antioxidant for food applications.

Synthesis, characterization, and in vitro digestion of electrosprayed and freeze-dried probiotics encapsulated in soy protein isolate-sunflower oil emulsions

This research evaluated the microencapsulation of the probiotic, Streptococcus thermophilus, in soy protein isolate (SPI) and sunflower oil (SO) emulsions using electrospraying and freeze-drying. Emulsions were formed with SPI (3–15% w/v), Tween 80® (2% w/v), and SO (5% w/v) after homogenization and ultrasonication. The Emulsion Stability Index (ESI), Emulsifying Ability Index (EAI), ζ-potential, particle size, Polydispersity Index (PDI), conductivity, and viscosity were evaluated to compare the emulsion properties at varying SPI:SO concentrations. After probiotic inclusion, the emulsions were electrosprayed and freeze-dried, and the microcapsules’ properties were evaluated (encapsulation efficiency, loss of viability, drying yield, surface hydrophobicity) and characterized (Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Laser Scanning Confocal Microscopy, and Differential Scanning Calorimetry). The ζ-potential (−51.51 mV) and other emulsion parameters obtained after ultrasonication indicated that the emulsion stability had improved. The secondary protein structure modifications were revealed by the emulsions' FTIR spectra, with significant increments in the α-helix and β-turn of the ultrasonicated samples compared to SPI. The electrosprayed microcapsules (13% SPI, 5% SO) demonstrated the highest encapsulation efficiency (90.51%) and the lowest loss of viability (1.05 log·CFUmL−1). The probiotics in the microcapsules were validated by the LSCM images and FTIR spectra. The differences in the morphological properties of freeze-dried and electrosprayed particles were observed through SEM. The electrosprayed microcapsules demonstrated the highest intestinal phase survival (77.03%) of probiotics under simulated gastrointestinal conditions, suggesting targeted probiotic delivery with potential for inclusion in nutraceuticals and functional foods.

Physicochemical, Structural Structural and Functional Properties of Non-Waxy and Waxy Proso Millet Protein.

The physicochemical, structural and functional properties of proso millet protein from waxy and non-waxy proso millet were investigated. The secondary structures of proso millet proteins consisted mainly of a β-sheet and ɑ-helix. The two diffraction peaks of proso millet protein appeared at around 9° and 20°. The solubility of non-waxy proso millet protein was higher than that of waxy proso millet protein at different pH values. Non-waxy proso millet protein had a relatively better emulsion stability index (ESI), whereas waxy proso millet protein had a better emulsification activity index (EAI). Non-waxy proso millet protein showed a higher maximum denaturation temperature (Td) and enthalpy change (ΔH) than its waxy counterpart, indicating a more ordered conformation. Waxy proso millet exhibited higher surface hydrophobicity and oil absorption capacity (OAC) than non-waxy proso millet, suggesting that the former may have potential applications as a functional ingredient in the food industry. There was no significant difference in the intrinsic fluorescence spectra of different waxy and non-waxy proso millet proteins at pH 7.0.

Fibrillation modification to improve the viscosity, emulsifying, and foaming properties of rice protein

Fibrillation of food proteins has attracted considerable attention as it can improve and broaden the functionality of proteins. In this study, we prepared three kinds of rice protein (RP) fibrils with different structural characteristics by the regulation of NaCl and explored the effect of protein structure on viscosity, emulsifying, and foaming properties. AFM results showed fibrils formed at 0 and 100 mM NaCl were mainly in the range of 50–150 nm and 150–250 nm, respectively. Fibrils formed at 200 mM NaCl were in the range of 50–500 nm and protein fibrils longer than 500 nm increased. There was no significant difference between their height and periodicity. Fibrils formed at 0 and 100 mM NaCl were more flexible and unordered than those formed at 200 mM NaCl. The viscosity consistency index K of native RP and fibrils formed at 0, 100, and 200 mM NaCl were determined. The K value of fibrils was higher than that of native RP. The emulsifying activity index, foam capacity and foam stability were enhanced by fibrillation, while longer fibrils exhibited lower emulsifying stability index, which may be because long fibrils resulted in difficulty of cover of emulsion droplets. In summary, our work provided a valuable reference for improving the functionality of rice protein and facilitated the development of protein-based foaming agents, thickeners, and emulsifiers.