Reduction In Droplet Size Research Articles

Long-term stability of sodium caseinate-stabilized nanoemulsions.

Oil-in-water (5 wt%) nanoemulsions were prepared with different concentration (2.5-10wt%) of sodium caseinate as a sole emulsifier and their long-term storage stability was investigated for 6months. Previous studies associated with sodium caseinate looked only into nanoemulsion formation; hence the challenges with long-term stability were not addressed. All nanoemulsions displayed an average droplet size <200nm, which remained unchanged over 6months. However, all of them displayed rapid creaming due to unabsorbed protein induced depletion flocculation, whose extent increased with protein concentration, although the cream layer formed was weak and re-dispersible upon gentle mixing. Microstructural analysis of the cream layer showed compaction of flocculated nanodroplet network with time leaving the aqueous phase out. Calculation of depletion interaction energy showed an increase in inter-droplet attraction with protein concentration and decrease with a reduction in droplet size, making the nanoemulsions more resistant to flocculation than conventional emulsions. This work aids in understanding the dependence of protein concentration on long-term stability of sodium caseinate-stabilized nanoemulsions.

Instant polysaccharide-based emulsions: impact of microstructure on lipolysis.

The development of emulsion-based products through optimisation of ingredients, reduction in energy-input during manufacture, while fulfilling healthy attributes, are major objectives within the food industry. Instant emulsions can meet these features, but comprehensive studies are necessary to investigate the effect of the initial formulation on the final microstructure and, in turn, on the in vitro lipolysis, comprising the double aim of this work. The instant emulsion is formed within 1.5-3 min after pouring the aqueous phase into the oil phase which contains a mixture of emulsifier (Tween 20), swelling particles (Sephadex) and thickeners (hydroxypropylmethylcellulose, HPMC, and guar gum, GG) under mild shearing (180 rpm). The creation of oil-in-water emulsions is monitored in situ by viscosity analysis, the final microstructure visualised by microscopy and the release of free fatty acids under simulated intestinal conditions quantified by titration. Increasing the concentration and molecular weight (Mw) of GG leads to smaller emulsion droplets due to increased bulk viscosity upon shearing. This droplet size reduction is magnified when increasing the Mw of HPMC or swelling capacity of viscosifying particles. In addition, in the absence of the emulsifier Tween 20, the sole use of high-Mw HPMC is effective in emulsification due to combined increased bulk viscosity and interfacial activity. Hence, optimisation of the ingredient choice and usage level is possible when designing microstructures. Finally, emulsions with larger droplet size (>20 μm) display a slower rate and lower extent of lipolysis, while finer emulsions (droplet size ≤20 μm) exhibit maximum rate and extent profiles. This correlates with the extent of emulsion destabilisation observed under intestinal conditions.

Estabilidad a largo plazo de emulsiones microfluidizadas para encapsulación por secado por aspersión

The long-term (60 days) effect of microfluidization on the properties of -carotene emulsions in a matrix of biopolymers (maltodextrin and gum arabic) for spray drying was evaluated. Microfluidization showed a significant effect (p ≤ 0.05) in the reduction of Emulsion Droplet Size (EDS) (262-721 nm). Emulsions with higher contents of gum arabic produce the smallest EDS (383-721 nm). EDS and the polydispersity index were directly related while stability and lightness were inversely related to EDS. The majority changes in the stability of emulsions were observed during the first 10 days, promoting the broke up for those emulsions with higher content of maltodextrin. Emulsions with large content of gum arabic remain stable for longer time, despite depletion flocculation due to excess biopolymer.

Evaluation of evaporation coefficient for micro-droplets exposed to low pressure: A semi-analytical approach

Evaporation rate of water is strongly influenced by energy barrier due to molecular collision and heat transfer limitations. The evaporation coefficient, defined as the ratio of experimentally measured evaporation rate to that maximum possible theoretical limit, varies over a conflicting three orders of magnitude. In the present work, a semi-analytical transient heat diffusion model of droplet evaporation is developed considering the effect of change in droplet size due to evaporation from its surface, when the droplet is injected into vacuum. Negligible effect of droplet size reduction due to evaporation on cooling rate is found to be true. However, the evaporation coefficient is found to approach theoretical limit of unity, when the droplet radius is less than that of mean free path of vapor molecules on droplet surface contrary to the reported theoretical predictions. Evaporation coefficient was found to reduce rapidly when the droplet under consideration has a radius larger than the mean free path of evaporating molecules, confirming the molecular collision barrier to evaporation rate. The trend of change in evaporation coefficient with increasing droplet size predicted by the proposed model will facilitate obtaining functional relation of evaporation coefficient with droplet size, and can be used for benchmarking the interaction between multiple droplets during evaporation in vacuum.

Tailoring the properties of PP/PA6 nanostructured blends by the addition of nanosilica and compatibilizer agents

The effectiveness of combining silica nanoparticles (NS) and polypropylene grafted with maleic anhydride (PPgMA) to stabilize the morphology and improve the properties of an immiscible PP/Nylon 6 blend was investigated. Blends of 80% polypropylene (PP) and 20% polyamide 6 (PA6) with a fixed amount of PPgMA and decreasing NS content were prepared by melt mixing. Two PPgMA compatibilizing agents with different grafting level and two modified NS, one hydrophilic and other hydrophobic, were employed. Used together, PPgMA and ∼4.0% of NS nanoparticles strongly reduced the PA6 droplet size, as a result of the preferential location of the NS at the interface avoiding drop coalescence. The effect was more remarkable when hydrophobic NS was added. Owing to the reduced droplet size, a fractioned crystallization of the PA6 dispersed phase was observed by DSC measurements, and self-nucleation experiments were carried out to elucidate the nature of the phenomenon. Despite the PA6 reduced size, the blends exhibited unsatisfactory mechanical performance. Thus, the NS content was decreased. In the end, a PP/PA6 blend stabilized with 1.6% hydrophobic NS and compatibilized with high grafting level PPgMA exhibited a fine-tuned morphology with enhanced ductility and barrier properties. NS nanoparticles act as outstanding stabilizers but do not promote interfacial adhesion between the phases. Therefore, the use of an optimal content of NS along with a compatibilizer yields a synergistic effect on the PP/PA6 blend.

Characterizing the novel surfactant-stabilized nanoemulsions of stinging nettle essential oil: Thermal behaviour, storage stability, antimicrobial activity and bioaccessibility

Nanoemulsions stabilized with nonionic surfactants (Tween 40, 60, 80) at the different surfactant-to-oil ratios (SORs, 0.25–2.0) were performed and their thermal behaviour, droplet size, storage stability, antimicrobial (minimum inhibitory concentration; MIC) and biological (in vitro digestion extent and bioaccessibility rate) characteristics of stinging nettle essential oil were studied. Thermal stability of the nanoemulsions was studied through a controlled heating-cooling cycle and showed significant differences in their turbidity depending on the type of used surfactant. The Ostwald ripening rate as the main destabilization mechanism at 25°C was lower than that at 4°C after 28days storage, which was in agreement with the Lifshitz–Slezov–Wagner (LSW) theory. The developed nanoemulsions exhibited a much strong antimicrobial activity in particular against Gram-positive bacteria. A significant increase in the lipolysis extent and bioaccessibility rate was found with a reduction in droplet size at SORs ≥1.0.

A scattering methodology for droplet sizing of e-cigarette aerosols

Context: Knowledge of the droplet size distribution of inhalable aerosols is important to predict aerosol deposition yield at various respiratory tract locations in human. Optical methodologies are usually preferred over the multi-stage cascade impactor for high-throughput measurements of aerosol particle/droplet size distributions.Objective: Evaluate the Laser Aerosol Spectrometer technology based on Polystyrene Sphere Latex (PSL) calibration curve applied for the experimental determination of droplet size distributions in the diameter range typical of commercial e-cigarette aerosols (147–1361 nm).Materials and methods: This calibration procedure was tested for a TSI Laser Aerosol Spectrometer (LAS) operating at a wavelength of 633 nm and assessed against model di-ethyl-hexyl-sebacat (DEHS) droplets and e-cigarette aerosols. The PSL size response was measured, and intra- and between-day standard deviations calculated.Results: DEHS droplet sizes were underestimated by 15–20% by the LAS when the PSL calibration curve was used; however, the intra- and between-day relative standard deviations were < 3%. This bias is attributed to the fact that the index of refraction of PSL calibrated particles is different in comparison to test aerosols. This 15–20% does not include the droplet evaporation component, which may reduce droplet size prior a measurement is performed. Aerosol concentration was measured accurately with a maximum uncertainty of 20%. Count median diameters and mass median aerodynamic diameters of selected e-cigarette aerosols ranged from 130–191 nm to 225–293 nm, respectively, similar to published values.Discussion and conclusion: The LAS instrument can be used to measure e-cigarette aerosol droplet size distributions with a bias underestimating the expected value by 15–20% when using a precise PSL calibration curve. Controlled variability of DEHS size measurements can be achieved with the LAS system; however, this method can only be applied to test aerosols having a refractive index close to that of PSL particles used for calibration.

Structural and emulsifying properties of sodium caseinate and lactoferrin influenced by ultrasound process

Structural, physical and emulsifying properties of sodium caseinate and lactoferrin were investigated after these proteins were subjected to ultrasound treatment. Aqueous sodium caseinate or lactoferrin solutions were sonicated for 2–6 min using a power of 300 W. Protein properties as size, surface charge, molecular weight distribution, intrinsic viscosity, surface hydrophobicity and structural conformation from circular dichroism were evaluated. Sodium caseinate size was significantly reduced after ultrasound treatment while an opposite effect was observed for lactoferrin. Slight differences in molecular weight after ultrasound treatment were observed only for lactoferrin. Intrinsic viscosity and surface hydrophobicity was positively affected by the increase of sonication time. Circular dichroism spectra revealed no differences for sodium caseinate structure but slight changes were observed for lactoferrin. In addition, a fixed amount (1 wt%) of this ultrasound-treated protein was employed as an emulsifier to prepare oil in water emulsions (o/w). Emulsions were also produced using the same ultrasound conditions that aqueous protein solutions were subjected. They were evaluated in terms of droplet size, emulsifying activity, creaming index and emulsion stability. Emulsions showed reduced droplet size and improved stability with higher sonication times. Coarse emulsions stabilized by ultrasound-treated proteins showed a slightly higher stability when compared to coarse emulsions stabilized by non-treated proteins. However, completely stable emulsions were produced only by ultrasound emulsification of coarse emulsions, suggesting that the protein changes occurring simultaneously to the droplets size reduction contributed to the enhancement of emulsifying properties.

Steam injection impact on the performances of nozzle grid in wet-vapor stream

Results of experimental study of the efficiency of intra-channel steam injection on the surface of nozzle grids of steam turbines operating in the wet steam flow are presented. The main objective of this study was to determine the basic mechanisms of the steam injection impact on the kinematic characteristics of the liquid phase outside an isolated nozzle grid. The kinetic energy loss distributions of the liquid phase and sliding coefficients of droplets along the grid spacing depending on the injected steam pressure at different theoretical values of the Mach number and the initial wetness are presented. The efficiency index was determined taking into account the kinetic energy loss distribution for the liquid phase along the grid spacing, depending on the pressure reduction on the slot. The investigation was conducted using the total pressure probe placed behind the object under study. The average diameters of large droplets of erosion-hazardous liquid phase at a certain distance from the grid were determined. In measuring the characteristics of the liquid phase particles, a laser diagnostics system of streams was used, based on the “POLIS” complex. The main advantage of this complex is the fact that it is contactless, which allows one to measure characteristics of the liquid phase particles without any distortion of the results and aerodynamic influence on the main stream. It is established that an intra-channel steam injection promotes the destruction of liquid film that formed as a result of the condensation of liquid droplets on the surfaces of nozzle blades, as well as the alignment of the velocity field and the average size reduction of droplets behind the grid. The experimental results have shown that the efficiency of injection (relative to the reduction of the amount of erosion-hazardous droplets) of hot steam substantially depends on the flowing regime of wet steam.

Cyclodextrin and Meglumine-Based Microemulsions as a Poorly Water-Soluble Drug Delivery System

Cyclodextrins (CDs) and meglumine (MEG) are pharmaceutical excipients widely used to improve solubility of poorly water-soluble drugs. The purpose of this work was to study the effect of CDs or MEG on the internal microstructure of soya oil–based O/W microemulsions (MEs) and on the modulation of the solubility and release rate of Class II model hydrophobic drugs, sulfamerazine and indomethacin. The pseudoternary phase diagrams revealed that higher proportions of oil phase, as well as the presence of β-cyclodextrin (ßCD), methyl-ßCD, and MEG, favored the incorporation of the drugs. The conductivity studies, particle size, and zeta potential analysis showed that the O/W ME structure remained unaffected and that the ME presented reduced droplet sizes after the incorporation of the ligands. The drug-component interactions were assessed by proton nuclear magnetic resonance studies. The highest incorporations of sulfamerazine (35.6 mg/mL) and indomethacin (73.1 mg/mL) were obtained with the ME with W = 5%, MEG and W = 1.8% ßCD in a phosphate buffer solution of pH 8, respectively. In addition, the ligands in ME significantly enhanced the released amount of the drugs, probably due to a solubilizing effect that facilitates the drug to penetrate the unstirred water layer adjacent to membranes.

Mechanical and water barrier properties of isolated soy protein composite edible films as affected by carvacrol and cinnamaldehyde micro and nanoemulsions

Edible films may be used in food packaging, for which they must deliver good barrier and mechanical properties. Films based on proteins have good gas barrier and mechanical properties, but poor water barrier properties. Films made from lipids have good water barrier properties, but poor mechanical properties. Protein and lipids were then combined to form composite films, and the particle size of the lipid phase was reduced to evaluate its effect on the mechanical and barrier properties. Micro and nanodroplets of Acetem and Tween 60 were added into an isolated soy protein (ISP) solution. Oil-in-water droplets were formed by direct emulsification at 1300 rpm for 30 min (microdroplets) or 5 h (nanodroplets), dispersed into the ISP solution, and cast into films. Emulsified films showed reduced strength and increased elongation, indicating a plasticizing effect of emulsions. The water barrier properties were either unchanged or slightly improved by the addition of hydrophobic compounds. Reducing droplet size improved the barrier properties as surface area of the lipid increased. Carvacrol and cinnamaldehyde were also added, and they either improved or unaffected the mechanical and barrier properties of ISP films. Addition of emulsions and reduction of droplet size generally decreased total pore volume in the films as well as water vapor permeation, indicating that the microvoid model suitably explains the water barrier properties of ISP films. This work further clarifies possible differences in barrier properties by examining water diffusivity and adsorption/desorption kinetics.

Physicochemical Characterization and Clinical Evaluation of a Microemulsion System for Topical Delivery of Tazarotene in Psoriasis

The purpose of the present study was to evaluate the potential application of microemulsion as a dermal drug delivery system for a poorly water soluble drug-tazarotene and enhance its topical bioavailability. Various oils were screened based on solubility studies and isopropyl myristate was selected as the oil phase. Pseudo-ternary phase diagrams were developed for various microemulsion formulations composed of isopropyl myristate (oil phase), Tween 80 (surfactant), propylene glycol (cosurfactant) and water. The physicochemical properties and the permeability of tazarotene were investigated for the optimized microemulsion. This developed microemulsion was incorporated into Carbopol 934 based gel to facilitate its topical application. In-vitro drug diffusion of optimized formulation was studied using Franz diffusion cells. In-vitro drug diffusion after 8 h from the microemulsion incorporated gel was 72.01± 2.50%, while that from Tazret® (marketed product) was 61.59± 2.03%. Ex-vivo study using rat skin indicated that microemulsion incorporated gel had better skin deposition capacity (18.23± 1.00%) as compared to marketed formulation (7.23± 0.66%). The clinical efficacy of the test formulation was evaluated in psoriasis patients. Percent change in Psoriasis status after 6 weeks was 4.80± 1.74% and 17.36± 0.98% in treatment with ME incorporated gel and Tazret® respectively (p value < 0.05). The higher efficacy of the developed microemulsion system was attributed to the combined effect of increased solubility and reduced droplet size of microemulsion systems leading to increased deposition in the skin. The results suggest that microemulsions are potential vehicles for improved topical delivery of tazarotene to treat psoriasis. Keywords: Microemulsion, pseudo-ternary phase diagram, tazarotene, topical bioavailability, topical drug delivery.

Ultrasound-assisted encapsulation of annatto seed oil: Whey protein isolate versus modified starch

The objective of this study was to compare the performance of whey protein isolate (WPI) and modified starch (SF) based on their surface properties as adsorbents in the oil–water interface aiming the encapsulation of the annatto seed oil by ultrasound-assisted emulsification. We also analyzed the influence of WPI and SF on technological quality of the microparticles formed from the respective emulsions by freeze-drying (FD) and spray-drying (SD). The effects of ultrasonication power and processing time were assessed by the droplet size of the dispersed phase and creaming stability. The finer emulsions obtained with the evaluated biopolymers were subjected to the FD and SD processes. The obtained microparticles were characterized with respect to moisture content, size distribution and average diameter, morphology, surface oil, entrapment efficiency, encapsulation efficiency, X-ray diffraction patterns and thermal stability. Ultrasound-assisted emulsification of the oil led to the formation of fine kinetically stable emulsions. Intensification of the ultrasonication process had no positive effects on reducing droplet size, demonstrating the existence of a physico-chemical limit imposed by the characteristics of WPI and SF. The FD and SD techniques resulted in different microparticle sizes and morphologies; however, the microparticles formed using both techniques exhibited an amorphous state. Micrographs obtained by confocal laser scanning microscopy (CLSM) demonstrated encapsulation of the oil in all of the treatments; however, the WPI-FD microparticles showed greater entrapment efficiency, while the SF-SD microparticles showed greater encapsulation efficiency. The type of biopolymer and method used to form the microparticles had no effect on thermal stability because both microparticles showed high stability to thermal degradation.

Morphology and rheological behavior of poly(butylene terephthalate)/polypropylene blends filled by two types of organoclays

The present research investigates the morphology and rheological behavior of poly(butylene terephthalate)/polypropylene (PBT/PP) blends containing hydrophilic and hydrophobic organoclays. The distribution of nanoclays and morphology of nanocomposites were analyzed using X-ray diffraction (XRD) and transmission and scanning electron microscopies. The XRD patterns show that the level of intercalation structure in nanocomposites reinforced by hydrophilic nanoclay is significantly higher than nanocomposites filled by hydrophobic one. According to morphological analysis, both types of nanocomposites indicate the reduction of droplet size, whereas hydrophilic nanoparticles illustrate more compatibilization efficiency than hydrophobic. According to transmission electron microscopy, hydrophilic nanoclays are mainly localized in the PBT matrix and at the interface, whereas hydrophobic nanoparticles are confined in the PP-dispersed phase and at the interface. From the rheological point of view, the results show that nanocomposites with hydrophilic nanoclay show stronger pseudoplasticity, higher viscosity, and more elasticity than nanocomposites with the hydrophobic one. The localization of hydrophilic organoclay in the PBT matrix aids to finer morphology of the PBT/PP blend, whereas hydrophobic one resists the breakup of droplets by confinement in dispersed phase.

Eucalyptus oil nanoemulsion-impregnated chitosan film: antibacterial effects against a clinical pathogen, Staphylococcus aureus, in vitro.

Eucalyptus oil (Eucalyptus globulus) nanoemulsion was formulated using low-and high-energy emulsification methods. Development of nanoemulsion was optimized for system parameters such as emulsifier type, emulsifier concentration, and emulsification methods to obtain a lower droplet size with greater stability. The minimized droplet diameter was achieved using the high-energy method of ultrasonication. Tween 80 was more effective in reducing droplet size and emulsion appearance when compared to Tween 20. Stable nanoemulsion was formulated with Tween 80 as a surfactant, and the particle size was found to be 9.4 nm (1:2 v/v). The eucalyptus oil nanoemulsion was impregnated into chitosan (1%) as a biopolymer in varying concentrations. Further, the film was characterized by moisture content, microscopic study, X-ray diffraction, and Fourier transform infrared spectroscopy. Also, the film with and without nanoemulsion was evaluated against Staphylococcus aureus. The nanoemulsion-impregnated chitosan film showed higher antibacterial activity than chitosan film. These results support the inclusion of nanoemulsion-impregnated chitosan film in wound management studies.

Design for Two-Fluid Fine Nozzle with 50% Fill Ratio

Sufficient air insert by reduced liquid in flashing propellants are required to produce fine droplet size with symmetrical spray in an aerosol atomiser without swirling design. It is called novel matched valve-actuator with two-fluid fine nozzle. Two-fluid fine nozzle design is an arrangement between air-assist atomiser insert, air blast and effervescent atomiser insert. However, 50% fill ratio and 9bar on pressure can with a currently acceptable become “Benchmark Objective” in this research. The results shows a few measurement with the same volume flow rate and variable flow rate of two fluids atomiser which have been taken in the experimental. 50 ml/min for liquid flow rate and 150ml/min flow rate of insert gas could reduce droplet size less than 70μm SMD by modifying the insert to promote greater cone angle and droplet size distribution with differences on quantity of air, liquid supply and the atomising velocity. Validation of two-fluid fine nozzle results is also recommended to be carried out and compared with the experiment results which related to turbulence kinetic energy with the atomiser insert and droplet size. Further researches are concentrating on modelling droplet breakup downstream of the atomiser insert.Keywordaerosol atomiser, two-fluid fine nozzle, fill ratio, droplet size.

Whey protein edible films modified with almond and walnut oils

Whey protein isolate films with almond or walnut oils at low concentrations (0.5 and 1.0%) were prepared through emulsification in order to modify the functional properties of the films. Optical (colour and opacity), mechanical (tensile strength, Young's modulus, and elongation at break), barrier (water vapour, oxygen, and carbon dioxide permeability), surface (contact angle on both air and support film sides through time) properties and microstructure of whey protein emulsified films were determined. Bimodal distribution of oil droplets in film-forming solutions was observed by light scattering granulometry. The reduction of lipid droplet size upon increasing oil content caused weakened mechanical resistance of the films. Addition of oils leads to opaque films with heterogeneous microstructure, resulting in an increase in film opacity. The swelling, water vapour permeability, and surface hydrophilicity of the whey protein films were reduced due to the addition of the oils. An increase in oxygen and carbon dioxide permeability with increasing oil content was observed. Contact angle measurements through time showed the absorption of water droplets by the emulsified films, whereas the control film showed a swelling effect. Almond oil had a stronger plasticizing effect and was more effective in modifying the properties of whey protein films. The obtained results revealed that almond and walnut oils used at low concentrations enhanced the hydrophobic character of the whey protein films and have a good potential for incorporation into whey protein isolate to make edible films or coatings for some food applications.

Characterization of Effects of Silica Nanoparticles on (80/20) PP/PS Blends via Nonlinear Rheological Properties from Fourier Transform Rheology

Effects of silica nanoparticles with different natures (hydrophilicity and hydrophobicity) on (80/20) PP/PS blends were investigated via linear and nonlinear rheological properties. The hydrophilic silica nanoparticle was fumed silica OX50 while the two hydrophobic ones were precipitated silica D17 and fumed silica R202. SEM images revealed that hydrophilic OX50 could not improve morphological properties of the blends. On the other hand, the two hydrophobic silica nanoparticles (R202 and D17) improved morphological properties. TEM examination showed that OX50 silica nanoparticles aggregated inside PS droplets, thereby making breakup of PS (dispersed) phase into smaller sizes more difficult. D17 and R202 improved morphological properties regardless of the different droplet size reduction mechanisms, and rheological properties improved as a result. Both linear rheological properties from SAOS (small-amplitude oscillatory shear) tests and nonlinear rheological properties from LAOS (large-amplitude oscillator...

Process optimisation of rotating membrane emulsification through the study of surfactant dispersions

In this study, a rotating membrane emulsification setup incorporating a 6.1μm pore diameter Shirasu porous glass membrane was used to produce oil-in-water emulsions. The processing conditions varied between 0.2 and 1.5bar for the transmembrane pressure and shear rates at the membrane surface between 0.6s−1 and 104.6s−1 were generated. All emulsions consisted of 10vol.% of sunflower oil stabilised by one of four different surfactants (Tween 20, Brij 97, lecithin and sodium dodecyl sulphate) of either 0.1wt.% or 1wt.% concentration. A novel approach for emulsification processing was introduced which incorporates high hydrophilic–lypophilic balance, non-ionic surfactants within the dispersed phase rather than the continuous phase. A reduction in droplet size by at least a factor of 3 for the same formulation can be achieved without significant hindrance on disperse phase flux. This therefore suggests a possible strategy for further process optimisation.

Constitutive activation of Drosophila CncC transcription factor reduces lipid formation in the fat body

Accumulating evidence indicates that the vertebrate stress-response transcription factors Nrf1 and Nrf2 are involved in hepatic lipid metabolism. However, the underlying molecular mechanisms of Nrf1-and Nrf2-mediated lipid metabolism remain unclear. To elucidate the precise roles of Nrfs in this process, we analyzed the physiological role of CncC in lipid metabolism as a Drosophila model for vertebrate Nrf1 and Nrf2. We first examined whether CncC activity is repressed under physiological conditions through a species-conserved NHB1 (N-terminal homology box 1) domain, similar to that observed for Nrf1. Deletion of the NHB1 domain (CncCΔN) led to CncC-mediated rough-eye phenotypes and the induced expression of the CncC target gene gstD1 both in vivo and in vitro. Thus, we decided to explore how CncCΔN overexpression affects the formation of the fat body, which is the major lipid storage organ. Intriguingly, CncCΔN caused a significant reduction in lipid droplet size and triglyceride (TG) levels in the fat body compared to wild type. We found that CncCΔN induced a number of genes related to innate immunity that might have an effect on the regulation of cellular lipid storage. Our study provides new insights into the regulatory mechanism of CncC and its role in lipid homeostasis.