Emulsification properties of amylose-fatty sodium salt inclusion complexes

Structure and functionality of surface-active amylose-fatty amine salt inclusion complexes

Novel value-added starch-based materials can be produced by forming amylose inclusion complexes (AIC) with hydrophobic compounds. There is currently little research on AIC use as polymeric emulsifiers, particularly for AIC with fatty amine salt ligands. This work evaluated AIC emulsifiers by studying the structure and functionality of AIC composed of high amylose corn starch and fatty amine salts (10-18 carbons, including a mixture simulating vegetable oil composition) produced via steam jet cooking. X-ray scattering verified successful AIC formation, with peaks located near 7.0°, 12.8° and 19.9° 2θ. AIC were easily dispersed in water (80-85 °C) and remained in suspension at room temperature for weeks, unlike the uncomplexed ligands or starch. AIC were highly effective emulsifying agents, with emulsifying activity indexes of 213-229 m2g-1 at pH 5, and zeta potentials, a measure of electrostatic repulsion, as high as 43.4 mV. AIC dispersions had surface tension ranging from 24 to 41 mN/m and displayed surface-active properties superior to amylose complexes formed from fatty acid salts and competitive with common starch-based emulsifiers. These findings demonstrate that fatty amine salt AIC are effective emulsifiers that can be made from low-cost sources of fatty amine salts, such as vegetable oil derivatives.

Amylose content and pre-freezing regulate the structure and oil absorption of polyelectrolytes-based starch cryogel

Starch cryogel is a potential material for oil absorption. This study provided a facile and convenient polyelectrolyte-based preparation strategy of starch cryogel, in which the structural properties of the cryogel were regulated by amylose content and pre-freezing without long-time retrogradation. Sodium laurate was used as a guest model to form starch-fatty acid salt complex (polyelectrolyte). The amount of amylose content and sodium laurate added led more polyelectrolytes, significantly increased V-type crystallinity from 3.72 % to 22.40 % and complexing index from 4.32 % to 28.48 %. As the uniform pore structure improved the oil absorption ability of starch cryogel, the starch cryogel prepared by waxy maize starch followed by quick pre-freezing showed the highest specific surface area (9.87 m²/g) and oil absorption capacity (32.94 g/g). Our findings suggest that polyelectrolyte properties have great potential in the preparation of starch-based cryogels, which could be applied in the design of novel starch-based porous materials.

A review on octenyl succinic anhydride modified starch-based Pickering-emulsion: Instabilities and ingredients interactions

Pickering emulsions endow attractive features and a wide versatility in both food and nonfood fields. In the last decades, a noticeable interest has emerged toward the use of octenyl succinic anhydride (OSA)-starch to improve the long-term stability in such systems. In this review, instabilities were pointed out, where a new kinetic equilibrium was observed in Pickering emulsions assigned to migration and size variations of particles. These features were monitored using rheological measurements to understand microstructure and droplets mobility. The elastic modulus (G'), the viscous modulus (G″), and tan(δ) values were attributed to the transition from solid to fluid and assigned to the instability of the formulation regardless of the type of the system configuration. The novelties in using OSA-modified starch, were also exposed. The chemical modification of starch decreased creaming for months. Interaction between OSA-modified starches and some ionic components (potassium, magnesium, and calcium) as well as hydrocolloids and proteins reduced creaming and coalescence due to dense interfacial film. Furthermore, the key parameters (oil fraction, fatty acids composition, oxidative stress oil polarity, and oil viscosity) that govern oil phase in Pickering emulsion, were analyzed. These parameters were found to be positively correlated to the stability of Pickering emulsions.

Utilization of lignocellulosic biomass: A practical journey towards the development of emulsifying agent

With each passing year, the agriculture and wood processing industries generate increasingly high tonnages of biomass waste, which instead of being burned or left to accumulate should be utilized more sustainably. In parallel, advances in green technology have encouraged large companies and nations to begin using eco-friendly materials, including eco-friendly emulsifiers, which are used in various industries and in bio-based materials. The emulsion-conducive properties of lignocellulosic materials such as cellulose, hemicellulose, and lignin, the building blocks of plant and wood structures, have demonstrated a particular ability to alter the landscape of emulsion technology. Beyond that, the further modification of their structure may improve emulsion stability, which often determines the performance of emulsions. Considering those trends, this review examines the performance of lignocellulosic materials after modification according to their stability, droplet size, and distribution by size, all of which suggest their outstanding potential as materials for emulsifying agents.

Physicochemical properties of heat-moisture treated, sodium stearate complexed starch: The effect of sodium stearate concentration

Amylose‑sodium stearate (SS) complexes (2, 5 and 8%) in heat-moisture treated potato starch (HPS) were evaluated for their physicochemical properties. Based on the DSC thermograms, the amylose - SS complexes were successfully formed with high thermal stability, indicated by a melt temperature (T_peak) of ≥ 112 °C for type I and ≥125 °C for type II complexes. Addition of 2% SS resulted in a single endothermal peak of the complexes, while 5 and 8% led to the formation of type I and II complexes with much higher enthalpy (ΔH) values. The XRD curve confirmed that the complexes were successfully formed. The pasting temperature increased from 66 °C for native to 91 °C for HPS145 complexed starch with 5% SS. Furthermore, the swelling power could be largely decreased, and the granular structure preserved. In addition, the inclusion complexation with SS on (HPS) succesfully improved the cook stabiliy.

Insecticidal Activity of Commiphora erythraea Essential Oil and Its Emulsions Against Larvae of Three Mosquito Species

The use of essential oils as ecofriendly tools for vector management is one of the mainstreams for biopesticide research. We evaluated the larvicidal properties of Commiphora erythraea (opoponax) essential oil and its fractions against Culex restuans Theobald, Culex pipiens L., and Aedes aegypti L. The use of bio-based amylose-N-1-hexadecylammonium chloride inclusion complex (Hex-Am) and amylose-sodium palmitate inclusion complex (Na-Palm) as emulsifiers for C. erythraea essential oil was also investigated. Bisabolene was the most abundant chemical constituent in the whole essential oil (33.9%), fraction 2 (62.5%), and fraction 4 (23.8%) while curzerene (32.6%) and α-santalene (30.1%) were the dominant chemical constituents in fractions 1 and 3, respectively. LC50 values for the whole essential oil were 19.05 ppm for Cx. restuans, 22.61 ppm for Cx. pipiens, and 29.83 ppm for Ae. aegypti and differed significantly. None of the four C. erythraea essential oil fractions were active against mosquito larvae. Two CYP450 genes (CYP6M11 and CYP6N12) and one GST gene (GST-2) were significantly upregulated in Ae. aegypti larvae exposed to C. erythraea essential oil suggesting their potential involvement in metabolic pathways for C. erythraea essential oil. Essential oil emulsions produced with Hex-Am were more toxic than the whole essential oil while those produced with Na-Palm had similar toxicity as the whole essential oil. These findings demonstrate that C. erythraea essential oil is a promising source of mosquito larvicide and that the use of Hex-Am as an emulsifier can enhance the insecticidal properties of C. erythraea essential oil.

Preparation and characterization of nanosized lignin from oil palm (Elaeis guineensis) biomass as a novel emulsifying agent

A study was carried out to determine the effectiveness of lignin, extracted from oil palm (Elaeis guineensis) biomass as water-in-oil (W/O) emulsifying agent. To achieve this goal, soda lignin (SL) was extracted via soda pulping process and a series of nanosized soda lignin (NSL) were prepared using homogenizer at three different speed i.e. 10,400 rpm (NSL 10), 11,400 rpm (NSL 11) and 12,400 rpm (NSL 12) for one hour. All prepared samples were characterized by FT-IR, UV-Vis spectroscopy, thermogravimetric analysis (TGA), zeta potential analyser, Transmission Electron Microscope (TEM) and Extreme High Resolution Field Emission Scanning Electron Microscope (XHR-FESEM). The result of FTIR showed that there is no prominent change occurred in spectra of all samples while a good stability was reflected by TGA curves. The percentage of creaming index and visual observations of all samples demonstrated that NSL 12 and dosage 2 g (out of 1 g, 1.5 g and 2 g) were found to be the best among all samples. Furthermore, the results of IFT indicate that NSL 12 was proven to be more stable than the commercial product. Therefore, NSL 12 is selected for toxicological studies and was found safe in both, in vitro and in vivo studies.

Leptospermum scoparium essential oil is a promising source of mosquito larvicide and its toxicity is enhanced by a biobased emulsifier

Synthetic pesticides are the cornerstone of vector-borne disease control, but alternatives are urgently needed to tackle the growing problem of insecticide resistance and concerns over environmental safety. Leptospermum scoparium J.R. Forst and G. Forst (manuka) essential oil and its four fractions were analyzed for chemical composition and toxicity against Aedes aegypti larvae. The use of bio-based amylose-N-1-hexadecylammonium chloride inclusion complexes (Hex-Am) as an emulsifier for L. scoparium essential oil was also investigated. Fraction 1 was inactive, fractions 2 (LC₅₀ = 12.24 ppm) and 3 (LC₅₀ = 20.58 ppm) were more toxic than the whole essential oil (LC₅₀ = 47.97 ppm), and fraction 4 (LC₅₀ = 35.87 ppm) had similar toxicity as the whole essential oil. Twenty-one chemical constituents were detected in L. scoparium essential oil compared to 16, 5, 19 and 25 chemical constituents in fractions, 1, 2, 3 and 4 respectively. The two most dominant chemical constituents were calamenene (17.78%) and leptospermone (11.86%) for L. scoparium essential oil, calamenene (37.73%) and ledene (10.37%) for fraction 1, leptospermone (56.6%) and isoleptospermone (19.73) for fraction 2, cubenol (24.30%) and caryophyllene oxide (12.38%) for fraction 3, and γ-gurjunene (21.62%) and isoleptospermone (7.88%) for fraction 4. Alpha-pinene, ledene, and aromandendrene were 2–7 times less toxic than the whole essential suggesting that the toxicity of L. scoparium essential oil was either due to other chemical constituents that were not tested or due synergist interactions among chemical constituents. Leptospermum scoparium essential oil-Hex-Am emulsion (LC₅₀ = 29.62) was more toxic than the whole essential oil. These findings suggest that L. scoparium essential oil is a promising source of mosquito larvicide and that Hex-Am is an excellent emulsifier for L. scoparium essential oil for use as a larvicide.

The Emulsifying Properties of Hydrogenated Rosin Xylitol Ester as a Biomass Surfactant for Food: Effect of pH and Salts

The xylitol ester of hydrogenated rosin (XEHR) was obtained for the first time from biomass-based hydrogenated rosin and xylitol using an environmentally friendly, high-pressure CO₂ catalytic synthesis. This compound is intended for use as an emulsifier for food. Analyses by ICP-AES showed the absence of heavy metal residues in the product, such that it met food standards. Fourier transform infrared and nuclear magnetic resonance spectroscopies together with gel permeation chromatography confirmed the successful esterification and the formation of a monoester and diester with molar masses of 427 and 772 g/mol. The emulsification of water/soybean oil mixtures by adding the XEHR was assessed at pH values of 4, 6.86, and 10 and in the presence of NaCl, KCl, MgCl₂, and CaCl₂. The XEHR was found to act as an emulsifier by reducing the interfacial tension of such mixtures to less than 2 mN/m under all conditions. The highest emulsifying activity index (9.52 m²/g) and emulsifying stability index (94.53%) were obtained after adding MgCl₂ (100 mM). Particle size and confocal microscopy showed that the presence of salts gave a more uniform droplet size and a finer emulsion structure. The high viscosities of the emulsions containing salts also suggested a more cohesive oil droplet network.

Amylose Inclusion Complexes as Emulsifiers for Garlic and Asafoetida Essential Oils for Mosquito Control

Although the insecticidal properties of some plant essential oils are well-documented, their use in integrated pest and vector management is complicated by their high volatility, low thermal stability, high sensitivity to oxidation, and low solubility in water. We investigated the use of bio-based N-1-hexadecylammonium chloride and sodium palmitate amylose inclusion complexes as emulsifiers for two essential oils, garlic and asafoetida, known to be highly toxic to mosquito larvae. Four emulsions of each essential oil based on amylose hexadecylammonium chloride and amylose sodium palmitate inclusion complexes were evaluated for their toxicity against Aedes aegypti L. larvae relative to bulk essential oils. All emulsions were significantly more toxic than the bulk essential oil with the lethal dosage ratios ranging from 1.09-1.30 relative to bulk essential oil. Droplet numbers ranged from 1.11 × 10⁹ to 9.55 × 10⁹ per mL and did not change significantly after a 6-month storage period. These findings demonstrated that amylose inclusion complexes enhanced the toxicity of essential oils and could be used to develop new essential oil based larvicides for use in integrated vector management.