High Emulsifying Activity Research Articles

Preparation and characterization of pickering emulsions stabilized by zein/quercetin/quaternary ammonium chitosan composite nanoparticles with antibacterial effect

The role of nanoparticles in the stabilizing interface is very important in the preparation of stable Pickering emulsions. In this study, ternary composite nanoparticles (ZQ-HC) were synthesized by complexing zein-quercetin covalent complex (ZQ) with quaternary ammonium chitosan (HTCC) and subsequently stabilized Pickering emulsions (ZQ-HC) with antibacterial activity. Results revealed that HTCC covers the surface of ZQ nanoparticles successfully, which designates an effective improvement in the surface wettability of ZQ effectively. Among them, ZQ-HC2:1 possesses the closest three-phase contact angle of 90° and the highest emulsification activity and emulsion stability. The results of ultra-high resolution microscopy showed that ZQ-HC nanoparticles were adsorbed at the oil-water interface to prevent droplet aggregation and improved the pH, ionic strength, and storage stability of the prepared Pickering emulsions. ZQ-HC nanoparticles construct an antioxidant barrier at the oil-water interface, improving the lipid oxidation stability of the emulsion. The ZQ-HC2:1 stabilized Pickering emulsion exhibits the most superior stability and strongest antibacterial activity against other emulsions. The ZQ-HC stabilized Pickering emulsions prepared in this study exhibit potential for use as carriers of bioactive ingredients in food applications.

الخصائص الوظيفية للمعزول والمتحلل البروتيني لمسحوق اوراق (.Moringa oleifera Lam)

The study aimed to estimate the functional properties of Moringa oleifera Lam. leaves powder protein isolate and its hydrolysates using pepsin. Water Holding Capacity (WHC) and Oil Holding Capacity (OHC) of protein isolate were 3.02 mL /g protein and 2.62 mL /g protein respectively, superior to the oil reducing capacity of the pepsin enzyme hydrolysates. at times 30 and 60 min. They were characterized by high emulsifying activity, reaching 48.08 m2/g and 53.06 m2/g, respectively, and outperforming the protein isolate, which reached 41.45 m2/g. The least emulsifying activity was for pepsin after 120 min of hydrolysis (A4) and reached 31.50 m2/g, and the highest emulsion stability was 63.77% for protein hydrolysates using pepsin enzyme at (37 ºC) after 60 min of hydrolysis (A2), while the least emulsifying stability was for protein hydrolysates using pepsin enzyme pepsin after 120 min (A4) it amounted to 25.10%. The foaming ability of protein hydrolysates using pepsin after 60 min (A2) was 41.17%, foaming stability at the beginning of hydrolysates was 39.02%, then it gradually decreased with the passage of time.

Production and characterization of extracellular liamocins produced from fungal strains of Aureobasidium spp.

Liamocins, a group of high-density glycolipids, are only produced by certain strains of the yeast-like fungi in the genus Aureobasidium. Until now, few studies have focused on the surfactant properties of liamocins produced from the highly diverse tropical strains of Aureobasidium. Therefore, the aims of this research were to screen the liamocin production from tropical strains of Aureobasidium spp. and to characterize their surfactant properties. A total of 41 strains of Thai Aureobasidium spp. were screened for their ability to produce liamocins, and the products were detected using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and thin-layer chromatography. Of those strains, 30 strains of Aureobasidium spp. tested were found to produce liamocins with yields ranging from 0.53 to 10.60g/l. The nature of all crude liamocins was heterogeneous, with different compositions and ratios depending on the yeast strain. These liamocins exhibited relatively high emulsifying activity against vegetable oils tested, with an emulsification index of around 40-50%; the emulsion stability of some liamocins was up to 30 days. The obtained critical micelle concentration values were varied, with those ​​of liamocins produced from A. pullulans, A. melanogenum and A. thailandense falling in ranges from 7.70 to 119.78, 10.73 to > 1,000, and 68.56 to > 1,000mg/l, respectively. The emulsification activity of liamocins was higher than that of the analytical grade rhamnolipids. These compounds showed strong surface tension reduction in a sodium chloride concentration range of 2-12% (w/v), pH values between 3 and 7, and temperatures between 4 and 121°C. This is the first report of liamocins produced by A. thailandense.

Bioemulsifier production by Acinetobacter venetianus AMO1502: Potential for bioremediation and environmentally friendly applications

At the best conditions of the bioprocess (30 °C, pH 7.0, 3.0 g/L NaCl) were obtained 0.66 g/L cell concentration, 3.3 g/L of bioemulsifier, which showed high emulsifying activity (53 % ± 2), reducing the surface tension of the water in 47.2 % (38 mN/m). The polymeric structure of the purified bioemulsifier comprised a carbohydrate backbone composed of hexose-based amino sugars with a monomeric mass of 1099 Da, structurally similar to emulsan. A. venetianus bioemulsifier is non-phytotoxic (GI% > 80 %) against Ocimum basilicum and Brassica oleracea and non-cytotoxic (LC50 5794 mg/L) against Artemia salina, being safe local organisms in comparison to other less eco-friendly synthetic emulsifiers. This bioemulsifier effectively dispersed spilled oil in vitro (C22–C33), reducing oil mass by 12 % (w/w) and dispersing oil in a displacement area of 75 cm2 (23.8 % of the spilled area). Thus, the isolated A. venetianus AMO1502 produced a bioemulsifier potentially applicable for environmentally friendly oil spill remediation.

Fabricating Pea Protein Micro-Gel-Stabilized Pickering Emulsion as Saturated Fat Replacement in Ice Cream.

Unsaturated fat replacement should be used to reduce the use of saturated fat and trans fatty acids in the diet. In this study, pea protein micro-gels (PPMs) with different structures were prepared by microparticulation at pH 4.0-7.0 and named as PPM (pH 4.0), PPM (pH 4.5), PPM (pH 5.0), PPM (pH 5.5), PPM (pH 6.0), PPM (pH 6.5), and PPM (pH 7.0). Pea protein was used as a control to evaluate the structure and interfacial properties of PPMs by particle size distribution, Fourier transform infrared spectroscopy (FTIR), free sulfhydryl group content, and emulsifying property. PPM (pH 7.0) was suitable for application in O/W emulsion stabilization because of its proper particle size, more flexible structure, high emulsifying activity index (EAI) and emulsifying stability index (ESI). The Pickering emulsion stabilized by PPM (pH 7.0) had a uniform oil droplet distribution and similar rheological properties to cream, so it can be used as a saturated fat replacement in the manufacture of ice cream. Saturated fat was partially replaced at different levels of 0%, 20%, 40%, 60%, 80%, and 100%, which were respectively named as PR0, PR20, PR40, PR60, PR80, and PR100. The rheological properties, physicochemical indexes, and sensory properties of low-saturated fat ice cream show that PPM (pH 7.0)-stabilized emulsion can be used to substitute 60% cream to manufacture low-saturated fat ice cream that has high structural stability and similar melting properties, overrun, and sensory properties to PR0. The article shows that it is feasible to prepare low-saturated fat ice cream with PPM (pH 7.0)-stabilized Pickering emulsion, which can not only maintain the fatty acid profile of the corn oil used, but also possess a solid-like structure. Its application is of positive significance for the development of nutritious and healthy foods and the reduction of chronic disease incidence.

Hot-air drying vs. lyophilization of sugar beet flakes for efficient pectin recovery and influence of extraction conditions on pectin physicochemical properties

This study assessed the influence of drying pretreatment and extraction conditions (type of acid and particle size of plant material) on the yield and physicochemical properties of pectin from sugar beet flakes resulted as by-product of sugar beet processing in the sugar industry. The results indicated that the drying conditions (hot-air drying and lyophilization) affected the extraction yield, the chemical composition of pectin, its color, degree of methylation and acetylation, molecular weight, and its rheological and emulsifying properties. The best results for pectin yield (16.20%), galacturonic acid content (91.19 g/100 g), degree of methylation and acetylation (66.93 and 23.87%), and molecular weight (3.89 × 105 g/mol) were obtained when sugar beet flakes were pretreated by hot-air drying, and the extraction was made with citric acid using plant material with particle sizes of 125–200 μm. This pectin also had high emulsion activity (51.42%) and emulsion stability (88.03%). The FT-IR spectra were similar, while pectin thermal behavior was affected by the drying pretreatment and extraction conditions. The results of this study showed that from this by-product of the sugar industry it can be extracted high quality pectin with rheological and emulsifying properties that are superior to commercial citrus and apple pectin.

Biorefining of legume and grass biomasses: Technological properties and bioactivities of the green juice

Five legume species (fodder galega, green pea, faba bean, red clover, and white clover) and one grass (timothy) grown under field conditions were investigated as potential future foods. Technological characteristics, such as emulsifying and foaming properties and nitrogen solubility indices, were determined from the green juices pressed from the whole plants. Secondly, the juices were evaluated for their antioxidative, antibacterial and anti-inflammatory properties. Faba bean green juice showed the highest emulsion stability and capacity, 66.0 ± 3.3 % and 18.0 ± 2.7 g/mg respectively, and second highest emulsion activity (58.4 ± 0.92 %). Considering the foaming properties, the highest activity was shown by white clover (433 ± 0.0 %) and green pea juices (411 ± 19.2 %). At the same time, the foam stability was remarkable for green pea juice (1078 ± 181.9 min) when compared to the other juices studied. The juices showed nitrogen solubility indices of about 50 % at pH 8, which were rather similar to those shown for the seeds of the same species in the literature. The antioxidant activities correlated with the total phenolic content. The highest antioxidant activity was shown by faba bean green juice both in the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) method. In addition, a weak positive correlation was observed between the total phenolic content and the antibacterial properties using Escherichia coli and Staphylococcus aureus strains, although mainly in the case of the latter strain, high inhibition readings were observed for all other plants than white clover. All juices showed some anti-inflammatory activity on human monocyte activation: the faba bean and red clover were the most efficient materials (IC50 concentrations 49 ± 41 and 206 ± 68 mg/L, respectively).- These results suggest that the green juices tested may provide novel health-promoting food and feed ingredients in the future.

Screening biosurfactant-producing actinomycetes: Identification of Streptomyces sp. RP1 as a potent species for bioremediation.

This study aimed to isolate biosurfactant-producing and hydrocarbon-degrading actinomycetes from different soils using glycerol-asparagine and starch-casein media with an antifungal agent. The glycerol-asparagine agar exhibited the highest number of actinomycetes, with a white, low-opacity medium supporting pigment production and high growth. Biosurfactant analyses, such as drop collapse, oil displacement, emulsification, tributyrin agar test, and surface tension measurement, were conducted. Out of 25 positive isolates, seven could utilize both olive oil and black oil for biosurfactant production, and only isolate RP1 could produce biosurfactant when grown in constrained conditions with black oil as the sole carbon source and inducer, demonstrating in situ bioremediation potential. Isolate RP1 from oil-spilled garden soil is Gram-staining-positive with a distinct earthy odor, melanin formation, and white filamentous colonies. It has a molecular size of ~621 bp and 100% sequence similarity to many Streptomyces spp. Morphological, biochemical, and 16 S rRNA analysis confirmed it as Streptomyces sp. RP1, showing positive results in all screenings, including high emulsification activity against kerosene (27.2%) and engine oil (95.8%), oil displacement efficiency against crude oil (7.45 cm), and a significant reduction in surface tension (56.7 dynes/cm). Streptomyces sp. RP1 can utilize citrate as a carbon source, tolerate sodium chloride, resist lysozyme, degrade petroleum hydrocarbons, and produce biosurfactant at 37°C in a 15 mL medium culture, indicating great potential for bioremediation and various downstream industrial applications with optimization.

Conjugation of gum Arabic and lentil protein hydrolysates through Maillard reaction: Antioxidant activity, volatile compounds, functional and sensory properties.

Lentil protein hydrolysates (LPH) and lentil protein hydrolysates cross-linked (LPHC) were grafted with gum Arabic (GA) through a wet Maillard reaction at 100°C for 2 h and called MLPH and MLPHC. The samples were assessed for absorption, degree of grafting (DG), surface hydrophobicity, antioxidant activity, molecular weight (MW) profile, chemical alteration, volatile compounds, functional and sensory properties. Results showed that Maillard grafting led to increase in absorption and DG (maximum value: MLPHC), and led to the reduction of the surface hydrophobicity and antioxidant activity (minimum value: MLPHC). MW profiles indicated that MLPH and MLPHC formed new bands at MW >250 kDa. Regarding the Fourier transform infrared spectroscopy (FTIR), Maillard conjugation led to the occurrence of peaks at 1759 and 1765 cm-1, while the intensities of amide I bands at 1637 and 1659 cm-1 and amide II bands at 1498 and 1495 cm-1 were decreased. Hydrolysis, cross-linking, and especially Maillard grafting provided well-balanced content of volatile components. Indeed, the proportions of alcohols, ketones, aldehydes, and acids were changed, thereby, the inherent grassy and planty tastes were diminished while new umami taste was developed. Maillard grafting led to significant improvement of functional properties, while MLPH and MLPHC indicated the highest emulsifying activity at pH 10.0 (73.76 and 70.12 m2/g, respectively) and stability (369.64 and 288.22 min), foaming capacity (88.57% and 142.86%) and stability (60.57% and 72%). Sensory analysis has demonstrated that umami taste was highly developed in MLPH and MLPHC, which can be well considered as meat proteins and flavor enhancers such as monosodium glutamate (MSG).

Screening of bioemulsifier-producing drugs to exclude mucus-forming and hydrocarbon destructors

The current study aimed to examine 271 bacterial isolates from the plant rhizosphere and oil-contaminated soil for the ability to produce extracellular bioemulsifiers. The bacterial isolates were screened for bioemulsifier production using several tests, including oil displacement, parafilm M destabilization, droplet collapse, and the emulsification index (E-24). The most effective strains were characterized by 8 isolates displaying an E-24 index greater than 60%. Among these, 6 strains isolated from plant rhizospheres demonstrated the ability to form mucus on solid media. The remaining two strains, Z2 and D1, were isolated from oil-contaminated soils and exhibited robust growth in a medium supplemented with oil and diesel. Surface tension was measured using the Wilhelmy plate method, finding low surface tension values of 57.6 ± 0.6 and 55.6 ± 0.6 mN/m for the culture supernatants of strains Z2 and D1, respectively. Further, a study on the cell hydrophobicity of strains Z2 and D1 revealed values above 70%, indicating high hydrophobicity. Strains Z2 and D1 were selected for their high emulsifying activity in the presence of edible oils and petroleum hydrocarbons, suggesting their potential as bioemulsifier producers.

Oil dispersion characterization of microorganisms producing biosurfactants

The article is dedicated to studying the ability of crude oil emulsification and displacement by bacteria producing low-molecular-weight biosurfactants. Six hydrocarbon-oxidizing cultures of microorganisms were used in this study: 3 strains of Pseudomonas aeruginosa (T1, T4, D2) and 3 Bacillus cultures: Bacillus licheniformis A3, Bacillus subtilis subsp. subtilis A12, Bacillus subtilis A9 from the collection of the Biotechnology Department of Al-Farabi Kazakh National University. The research findings indicate that cells of P. aeruginosa T1 exhibited maximum emulsifying and displacing properties, with an E24 value of 76.4% and an oil displacement ability of 5.1 cm. Among the three genes responsible for the production of low-molecular-weight biosurfactants, the presence of one gene, rhlA, responsible for the synthesis of rhamnolipid biosurfactants, has been confirmed. It was demonstrated that strains P. aeruginosa T1, P. aeruginosa T4, B. subtilis A9, and B. subtilis subsp. subtilis A12 showed high emulsifying activity, making them potentially effective for application in biotechnological processes aimed at enhancing oil recovery from mature reservoirs and in bioremediation processes.

Production and characterization of rhamnolipid biosurfactant from thermophilic Geobacillus stearothermophilus bacterium isolated from Uhud mountain.

Biosurfactants have been given considerable attention as they are potential candidates for several biotechnological applications. In this study, a promising thermophilic biosurfactant-producing HA-2 was isolated from the volcanic and arid region of Uhud mountain, Madinah, Saudi Arabia. It was identified using 16S rRNA gene sequence analysis. The biosurfactant production ability was screened using different methods such as the drop collapse test, oil spreading test, hemolytic activity test, CTAB test, and emulsification index. The ability of rhamnolipid production by the tested strain was confirmed by the polymerase chain reaction (PCR) of rhlAB. The affinity of thermophilic HA-2 to hydrophobic substrates was also investigated. Optimization of biosurfactant production was conducted. The biological activities of produced surfactant were investigated. The isolated HA-1 was identified as Geobacillus stearothermophilus strain OR911984. It could utilize waste sunflower frying oil (WSFF) oil as a low-cost carbon source. It showed high emulsification activity (52 ± 0.0%) and positive results toward other biosurfactant screening tests. The strain showed high cell adhesion to hexane with 41.2% cell surface hydrophobicity. Fourier-transform infrared (FTIR) spectra indicated the presence of hydrophobic chains that comprise lipids, sugars, and hydrophilic glycolipid components. The optimization results showed the optimal factors included potato peel as a carbon source with 68.8% emulsification activity, yeast extract as a nitrogen source with 60% emulsification activity, a pH of 9 (56.6%), and a temperature of 50° (72%). The kinetics showed that optimum biosurfactant production (572.4 mg/L) was recorded at 5 days of incubation. The produced rhamnolipid biosurfactant showed high antimicrobial activity against some human and plant pathogenic bacterial and fungal isolates and high antioxidant activity (90.4%). In addition, it enhanced wheat (Triticum aestivum) growth, with the greatest enhancement obtained with the 5% concentration. Therefore, thermophilic G. stearothermophilus is a promising rhamnolipid biosurfactant producer that utilizes many organic wastes. The produced biosurfactant could be applied as a promising emulsifier, antimicrobial, antioxidant, and plant growth promoter.

Enhancing the solubility and emulsion properties of rice protein by deamidation of citric acid-based natural deep eutectic solvents

The characteristics of rice protein deamidated (DRP) by choline chloride-citric acid and glucose-citric acid natural deep eutectic solvents (G-C NADES, C-C NADES) at different dilutions were investigated. Compared with the effect of citric acid deamidation on the structural and functional properties of the protein, the DRP from the NADESs led to remarkable differences in the degree of hydrolysis (DH), SDS-PAGE, morphology, surface hydrophobicity, average particle size, intrinsic fluorescence, amino acid compositions, and emulsion activity. The results of SDS-PAGE, DH, and SEM showed the NADESs reduced the occurrence of uncontrolled hydrolysis of protein during acid deamidation. DRP from C-C and G-C NADESs was found to significantly improve solubility. DRP prepared by C-C NADES showed a more than 40% solubility over a wide pH range associated with its higher emulsifying activity (37.62–44.19 m2/g) and emulsifying stability (73.76–86.9 min), as well as a better deamidation effect while lower DH. Thus, these findings showed that acid-based NADESs had great potential as a modified RP product to expand its application.

Effects of molecule weight on the emulsifying properties of dodecenyl succinic anhydride modified glucuronoxylans

Abstract Glucuronoxylans have been considered as an alternative polymer for petroleum polymers in coatings, films, emulsifiers, and other industries. In this study, different molecule weight glucuronoxylans were obtained through xylanase hydrolysis. Dodecenyl succinic anhydride (DDSA) was used as a modifying agent to functionalize glucuronoxylans. At the same degree of substitution (DS), higher molecule weight glucuronoxylans led to better emulsifying properties and emulsion stability. Higher molecule weight DDSA modified glucuronoxylans showed smaller droplets size, lower zeta potential, higher EA (emulsifying activity) and better emulsion stability. These results suggested that molecule weight has positive impact on the emulsifying properties of DDSA modified glucuronoxylans. Furthermore, DS had positive impact on the emulsifying properties of DDSA modified glucuronoxylans.

Complex bio-nanoparticles assembled by a pH-driven method: environmental stress stability and oil-water interfacial behavior.

Protein-based nanoparticles have gained considerable interest in recent years due to their biodegradability, biocompatibility, and functional properties. However, nanoparticles formed from hydrophobic proteins are prone to instability under environmental stress, which restricts their potential applications. It is therefore of great importance to develop green approaches for the fabrication of hydrophobic protein-based nanoparticles and to improve their physicochemical performance. Gliadin/shellac complex nanoparticles (168.87 ~ 403.67 nm) with various gliadin/shellac mass ratios (10:0 ~ 5:5) were prepared using a pH-driven approach. In comparison with gliadin nanoparticles, complex nanoparticles have shown enhanced stability against neutral pH, ions, and boiling. They remained stable under neutral conditions at NaCl concentrations ranging from 0 to 100 mmol L-1 and even when boiled at 100 °C for 90 min. These nanoparticles were capable of effectively reducing oil-water interfacial tension (5 ~ 11 mNm-1 ) but a higher amount of shellac in the nanoparticles compromised their ability to lower interfacial tension. Moreover, the wettability of the nanoparticles changed as the gliadin/shellac mass ratio changed, leading to a range of three-phase contact angles from 52.41° to 84.85°. Notably, complex nanoparticles with a gliadin/shellac mass ratio of 8:2 (G/S 8:2) showed a contact angle of 84.85°, which is considered suitable for the Pickering stabilization mechanism. Moreover, these nanoparticles exhibited the highest emulsifying activity of 52.42 m2 g-1 and emulsifying stability of 65.33%. The findings of the study revealed that gliadin/shellac complex nanoparticles exhibited excellent resistance to environmental stress and demonstrated superior oil-water interfacial behavior. They have strong potential for further development as food emulsifiers or as nano-delivery systems for nutraceuticals. © 2023 Society of Chemical Industry.

High–level production of a novel alginate lyase (FsAly7) from Flammeovirga sp. for efficient production of low viscosity soluble dietary fiber from sodium alginate

Sodium alginate is one of the most abundant sustainable gum source for dietary fiber production. However, the preparation efficiencies of low viscosity soluble dietary fiber from sodium alginate remain low. Here, a novel alginate lyase gene (FsAly7) from Flammeovirga sp. was identified and high–level expressed in Pichia pastoris for low viscosity soluble dietary fiber production. The highest enzyme production of 3050 U mL−1 was achieved, which is by far the highest yield ever reported. FsAly7 was used for low viscosity soluble dietary fiber production from sodium alginate, and the highest degradation rate of 85.5 % was achieved under a high substrate content of 20 % (w/v). The molecular weight of obtained soluble dietary fiber converged to 10.75 kDa. FsAly7 catalyzed the cleavage of glycosidic bonds in alginate chains with formation of unsaturated non-reducing ends simultaneously in the degradation process, thus altered the chemical structures of hydrolysates. The soluble dietary fiber exhibited excellent properties, including low viscosity, high oil adsorption capacity activity (2.20 ± 0.03 g g−1) and high emulsifying activity (60.05 ± 2.96 mL/100 mL). This investigation may provide a novel alginate lyase catalyst as well as a solution for the efficient production of low viscosity soluble dietary fiber from sodium alginate.

Protein concentrates from plain, aromatic and pigmented rice cultivars: Functional, thermal and morphological characterization

Protein is a vital nutrient required for growth and development of human population. It is well recognised that a significant cause of malnutrition is a lack of protein in human diet. Plant based proteins are becoming an excellent substitute for meat proteins in the development of functional foods at a fair price. When it comes to plant-based sources of high-quality protein, rice is regarded as a useful option because of its hypoallergenic properties, adequate amino acid balance, and high protein content. Therefore, protein concentrates were obtained from plain (SR-4, K-39), aromatic (Mushq Budij) and pigmented (Zhag) rice cultivars of Kashmir. Significant (p<0.05) difference was observed in protein (70.40–74.23 g/100 g) and ash (2.90–3.50 g/100 g) contents of protein concentrates isolated from different rice cultivars. Zhag protein had the lowest ‘L’ value (40.20). However, it had the highest emulsifying activity (47.29 m2/g) and emulsion stability index (13.38 min) at neutral pH. Moreover, water absorption capacity was highest for K-39 protein (1.90 g/g). Zhag protein had the highest protein solubility and foaming stability under acidic pH conditions. Zhag protein had the highest denaturation temperature (81.70 °C) and denaturation enthalpy (9.55 Jg−1). No sharp peaks were observed in the X-ray diffractogram (XRD), indicating amorphous behaviour of protein powder. Pearson's correlation revealed positive correlation between emulsifying activity indices (EAI) at pH 7 and protein solubility at pH 8 (r = 0.955, p<0.05). Surface hydrophobicity (SH) of RPCs was found to be positively correlated with EAI at pH 3 (r = 0.991, p<0.01) and foaming capacity (FC) at pH 8 (r = 0.994, p<0.01), respectively. It can be concluded from the present study that protein concentrate from pigmented rice cultivar was superior to other samples in terms of functionality and thermal attributes.

Soy protein isolate-guar gum-goose liver oil O/W Pickering emulsions that remain stable under accelerated oxidation at high temperatures.

Goose liver oil (GLO) is a solid-liquid mixture, rich in polyunsaturated fatty acids and high in nutritional value, but poor in fluidity and easily oxidized. Therefore, oil-in-water (O/W) Pickering emulsions of three polysaccharides and soy protein isolate (SPI) with GLO were prepared to improve the stability of it. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier-transform infrared spectroscopy, and zeta potential revealed that the SPI and complexes with konjac glucomannan, pectin, and guar gum (GG) ranged from 17 to 75 kDa, with the site of action being the -OH stretch and the amide group, and bound by hydrogen bonding. Adding konjac glucomannan and GG significantly increased the water contact angle of the SPI to 74.1° and 59.0°, respectively. Therefore, the protein-polysaccharide complexes could enhance the emulsion stability. In addition, the O/W Pickering emulsions with GLO had near-Newtonian fluid rheological properties with a significant increase in apparent viscosity and viscoelasticity, forming a dual network structure consisting of a ductile and flexible protein network and a rigid and brittle polysaccharide network. The microstructure observation indicated that the O/W emulsions were spherical and homogeneous. The highest emulsification activity was observed for the SPI-GG-GLO emulsions, without significant delamination or flocculation and high oxidative stability after 7 days in storage. These results demonstrate that the construction of SPI-GG-GLO O/W Pickering emulsions can stabilize GLO even at high temperatures that promote oxidation. © 2023 Society of Chemical Industry.

Biodegradation of Choline NTF2 by Pantoea agglomerans in Different Osmolarity. Characterization and Environmental Implications of the Produced Exopolysaccharide.

A specific microorganism, Pantoea agglomerans uam8, was isolated from the ionic liquid (IL) Choline NTF2 and identified by molecular biology. A biodegradation study was performed at osmolarity conditions (0.2, 0.6, 1.0 M). These had an important influence on the growth of the strain, exopolysaccharide (EPS) production, and biodegradation (1303 mg/L max production and 80% biodegradation at 0.6 M). These conditions also had an important influence on the morphology of the strain and its EPSs, but not in the chemical composition. The EPS (glucose, mannose and galactose (6:0.5:2)) produced at 0.6 M was further characterized using different techniques. The obtained EPSs presented important differences in the behavior of the emulsifying activity for vegetable oils (olive (86%), sunflower (56%) and coconut (90%)) and hydrocarbons (diesel (62%), hexane (60%)), and were compared with commercial emulsifiers. The EPS produced at 0.6 M had the highest emulsifying activity overall. This EPS did not show cytotoxicity against the tested cell line (<20%) and presented great advantages as an antioxidant (1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) (85%), hydroxyl radical (OH) (99%), superoxide anion (O2-) (94%), chelator (54%), and antimicrobial product (15 mm). The osmolarity conditions directly affected the capacity of the strain to biodegrade IL and the subsequently produced EPS. Furthermore, the EPS produced at 0.6 M has potential for environmental applications, such as the removal of hazardous materials by emulsification, whilst resulting in positive health effects such as antioxidant activity and non-toxicity.

Optimization and purification of bioproducts from Bacillus velezensis PhCL fermentation and their potential on industrial application and bioremediation

Bioproduction is considered a promising alternative way of obtaining useful and green chemicals. However, the downstream process of biomolecules has been one of the major difficulties in upscaling the application of bioproducts due to the high purification cost. Acid precipitation is the most common method for purifying biosurfactants from the fermentation broth with high purity. However, the use of strong acids and organic solvents in solvent extraction has limited its application. Hence, in this study, a new strain of Bacillus velezensis PhCL was isolated from phenolic waste, and its production of amylase had been optimized via response surface methodology. After that, amylase and biosurfactant were purified by sequential ammonium sulfate precipitation and the result suggested that even though the purified crude biosurfactant had a lower purification fold compared to the acid precipitation, the yield was higher and both enzymes and biosurfactant also could be recovered for lowering the purification cost. Moreover, the purified amylase and crude biosurfactant were characterized and the results suggested that the purified crude biosurfactant would have a higher emulsion activity and petroleum hydrocarbon removal rate compared to traditional surfactants. This study provided another approach for purifying bioactive compounds including enzymes and biosurfactants from the same fermentation broth and further explored the potential of the crude purified biosurfactant in the bioremediation of polycyclic aromatic hydrocarbons and petroleum hydrocarbons.