Storage Stability Analysis Research Articles

Interfacial structure modification and enhanced emulsification stability of microalgae protein through interaction with anionic polysaccharides

Microalgae protein (MP) have emerged as a focal point of research within food processing due to its nutritional value and foaming properties. However, its isoelectric point around pH 4 leads to it susceptible to collision, binding, and precipitation. Additionally, MP has poor emulsification properties and only shows stability under strongly alkaline conditions. This study investigated the effects of food-grade anionic polysaccharides (guar gum (GG), gum arabic (GA), low acyl gellan gum (LG), and pectin (PT)) on the molecular structure and emulsification properties of MP. Results indicated that these anionic polysaccharides enhanced the UV absorption of MP near 620 nm, especially at 14 % content, while fluorescence intensity decreased due to amino acid residues masking without structural changes. The addition of polysaccharides resulted in bimodal or multimodal particle size distributions, with LG and PT showing larger particle sizes. At pH 4, negatively charged polysaccharides formed stable complexes with near-neutral MP, improving solution stability via electrostatic repulsion and diminishing turbidity. The droplet distribution analysis indicated that higher anionic polysaccharide ratios (1:4, 1:2, and 1:1) correlated with smaller droplet sizes and increased emulsion stability. Zeta-potential measurements revealed negative charges for emulsions, with LG-MP and PT-MP complexes displaying higher absolute values (15.0 to 20.7 mV) compared to GG-MP and GA-MP complexes, indicating superior stability. Storage stability analysis showed that LG-MP and PT-MP complexes stabilized emulsions had minimal delamination over two weeks. Rheological assessments showed that increasing GG and GA contents from 14 % to 50 % had negligible effects on apparent viscosity, while LG-MP (1:1) complexes stabilized emulsion displayed higher viscosity compared to PT-MP emulsions. Frequency sweep results showed that GG-MP, GA-MP, and LG-MP emulsions had greater elastic moduli (G') than viscous moduli (G"), indicating elastic behavior, whereas PT-MP emulsions transitioned from liquid-like to solid-like behavior as frequency increased. This study illustrates the advantages of high LG and PT content in preventing particle aggregation and enhancing emulsion stability, providing a theoretical and practical foundation for MP applications in food processing.

Impact of reduced sucrose content on processed cheese: Sensory, textural, and storage stability analysis

The present study examines the impact of varying sucrose concentrations (12%, 6%, and 0%) on the sensory qualities and storage stability of processed cheese. Our findings reveal that sucrose is crucial for enhancing color depth, modulating flavor, and improving texture. Specifically, higher sucrose levels impart a caramel color, increase sweetness, and maintain a harmonious balance between salty and sour tastes, thereby mitigating the intensification of unwanted flavors (P < 0.05). Furthermore, sucrose acts as a structural element that bolsters viscoelastic properties and prolongs storage stability; increased sucrose content slows flavor degradation and preserves textural consistency over time. While reductions in sucrose do not significantly compromise the texture of fresh samples (P > 0.05), they necessitate adjustments in flavor profiles. This research highlights the essential role of sucrose in processed cheese and sets the stage for further studies on sugar reduction strategies and the potential use of alternative fillers, marking a significant step forward in the development of processed cheese products.

Asimina triloba seeds as a feedstock for energy conversion: Optimizing yield rate and characterizing fuel properties

In the present study, waste Asimina triloba seeds are proposed as a potential feedstock for biodiesel production, with the optimization of transesterification process parameters aimed at achieving higher yield rates. While previous studies have explored the use of Asimina triloba biodiesel for engine applications, this study stands out as the first to optimize transesterification process parameters for increased yield and to conduct comprehensive fuel characterization alongside storage stability analysis. The transesterification process parameters such as the methanol-oil molar ratio, catalyst volume concentration, reaction process temperature, and reaction process time are optimized by employing the response surface methodology. The response surface methodology analysis revealed that the proposed model is highly significant, with a coefficient of determination approaching unity. To achieve maximum biodiesel yield, the recommended parameters are a methanol-oil molar ratio of 14.7:1, a catalyst concentration of 2.4%, a reaction temperature of 81.3?C, and a reaction time of 138.8 minutes. Under these optimal conditions, the projected yield is 94.35%, aligning closely with experimental observations of 94.4%. The Fourier-transform infrared spectroscopy analysis underscored the substantial presence of carbon-based constituents in biodiesel, while the gas chromatography-mass spectrometry analysis revealed octadic-9,12-dienoic acid as the primary contributor. Furthermore, the stability profile demonstrates an extended stability period, complemented by physicochemical properties that align with the biodiesel standards specified by ASTM.

Cross-linked arginine deiminase aggregates for enhanced production of nutraceutical citrulline

Arginine deiminase (ADI) has been widely employed for the biological production of nutraceutical citrulline. However, sub-optimal enzyme properties, operational instability, and difficulty in reuse impede its industrial usage as well as increase the production cost. The present study describes a simple, cost-effective carrier-free immobilization technology that can circumvent these limitations. ADI was precipitated and cross-linked with glutaraldehyde to obtain novel cross-linked arginine deiminase aggregates (ADI-CLEA). A neural network-based multiobjective genetic algorithm (MOGA-NN) was employed to optimize the immobilization of ADI. MOGA-NN optimization yielded ADI-CLEA with 0.30 IU/mL activity and 61 % recovery. Structural characterization using TEM, SEM, FTIR, DLS/ZETA revealed that the developed ADI-CLEA were monodisperse, ultra-porous, and highly stable. ADI-CLEA showed an improved pH /temperature profile and resistivity against denaturants than free enzyme. The efficiency of ADI-CLEA in the industrial production of nutraceutical citrulline was also studied. ADI-CLEA produced 215.4 g/L citrulline in first cycle of usage. Reusability and storage stability analysis further showed that ADI-CLEA could be reused for more than seven consecutive cycles and stable for up to 50 days. In conclusion, this novel formulation increases the stability/robustness of ADI, eases the product separation process and could be reused for economically viable bioproduction of nutraceutical citrulline in industries.

Physicochemical properties and storage stability of commercial breads available in Tangail, Bangladesh

The research was conducted to examine the nutritional composition, physical attributes, organoleptic acceptability, and microbial quality for shelf life during storage of various commercial bread samples in Tangail, Bangladesh. A total of seven samples of several brands were purchased from retail shops for investigation. Results show the percentage of protein, moisture, ash, and fat content of the sample ranged between 7.66 ± 0.011–9.86 ± 0.005, 29.65 ± 0.005–32.18 ± 0.004, 0.73 ± 0.009–0.93 ± 0.012, and 1.55 ± 0.009–5.96 ± 0.01 respectively, significant at p < 0.05. The color measurement of all samples ranged from 71.91 to 77.22, − 4.91 to − 0.81, and 19.40–36.01 of L* , a* , and b* , respectively. In storage stability analysis, the hardness of all samples was increased (4.15 ×104 N/m2) and springiness was decreased (0.312) significantly (p < 0.05). The results of the microbial analysis found a total viable count 1 × 104 to 2.43 × 106 cfu/g and a total fungal count 1 × 104 to 1.46 × 106 cfu/g respectively, with storage time. According to the ICMSF, the microbiological quality of all bread was below acceptable levels after the third day of storage. Besides, texture and overall acceptability of bread were correlated with hardness and springiness and also related to storage. During five days of storage at room temperature, crumb hardening and springiness of the collected sample progressed. Finally, bakery owners as well as consumers should be concerned about hygiene and quality to make safe food products.

Effects of homogeneous and ultrasonic treatment on casein/phosphatidylcholine complex-emulsions: Stability and bioactivity insights

Casein (CAS), a typical protein emulsifier, has functional properties limited by its chemical structure in practical production applications. This study aimed to combine phosphatidylcholine (PC) and casein to form a stable complex (CAS/PC) and improve its functional properties through physical modification (homogeneous and ultrasonic treatment). To date, few studies have explored the effects of physical modification on the stability and biological activity of CAS/PC. Interface behavior analysis showed that compared to homogeneous treatment, PC addition and ultrasonic treatment could decrease the mean particle size (130.20 ± 3.96 nm) and increase the zeta potential (−40.13 ± 1.12 mV), indicating the emulsion is more stable. The chemical structural analysis of CAS showed that PC addition and ultrasonic treatment promoted changes in its sulfhydryl content and surface hydrophobicity, exposing more free sulfhydryl groups and hydrophobic binding sites, thereby enhancing its solubility and improving the stability of the emulsion. Additionally, storage stability analysis revealed that the incorporation of PC with ultrasonic treatment could improve the root mean square deviation value and radius of gyration value of CAS. These modifications resulted in an increase the binding free energy between CAS and PC (−238.786 kJ/mol) at 50 °C, leading to an improvement in the thermal stability of the system. Furthermore, digestive behavior analysis indicated that PC addition and ultrasonic treatment could increase the total FFA release from 667.44 ± 22.33 μmol to 1250.33 ± 21.56 μmol. In conclusion, the study underscores the effectiveness of PC addition and ultrasonic treatment in enhancing the stability and bioactivity of CAS, offering novel ideas for designing stable and healthy emulsifiers.

Absorption of oenothein B nanoparticles constructed using casein phosphopeptide and chitosan

The Oenothein B (OEB) rich in eucalyptus is a kind of extremely development of prospects of antioxidant activity, but low oral bioavailability limits its application. The novel polyelectrolyte nanoparticle was designed for OEB delivery through the self-assembly of casein phosphopeptides (CPP) and natural active polysaccharides-chitosan (CS). The OEB nanoparticle with small particle size and high embedding rate were constructed to solve the problem of low oral bioavailability of OEB, and its stability as well as in vivo absorption were investigated. The storage stability analysis, digital inverted fluorescence microscopy and emission field scanning electron microscopy showed that the particle size and total amount of OEB nanoparticles did not vary significantly after 96 h of continuous storage at room temperature, and the particle size distribution was uniform, and the particles kept their integrity pH 1.2. The maximum release rate of OEB nanoparticles was only 0.72% in artificial gastric fluid and 21.77% in artificial intestinal fluid. It greatly reduces the risk of its decomposition and plays a better protective role. The results of in vivo absorption showed that OEB nanoparticle gavage mice did not detect OEB in blood and its metabolites except for OEB in gastric juice, indicating that OEB changes in vivo after release. Therefore, although OEB nanoparticles can effectively protect their decomposition in gastrointestinal fluid, it is best to achieve sustained release at the target location in order to improve the absorption and utilization effect.

Ultrasound-assisted natural deep eutectic solvent extraction of anthocyanin from black carrots: Optimization, cytotoxicity, in-vitro bioavailability and stability

In the present study, natural deep eutectic solvent-based ultrasound-assisted extraction was introduced for the extraction of cyanidin-3-O-glycoside from black carrots. Response surface methodology (RSM) with central composite design with 27 experimental runs were used for the optimization studies. The analysis of variance indicated that the solid/solvent ratio and ultrasound power had a significant effect on the responses. The measured parameters corresponded to the predicted results. Cytotoxicity analyzes were performed after the verification of the data obtained as a result of the optimization. Based on the results of cytotoxicity analysis, the inhibitory effect of the extracts was proven on Caco-2 and HUH7 cell lines. Microencapsulation was achieved with the complex coacervation with three different wall materials to provide ease of use and to extend the shelf life. The pH, temperature and storage stability analysis results of the samples showed that +4 °C was the best storage temperature and the total monomeric anthocyanin content of the samples decreased with increasing storage time. Based on the findings, an eco-friendly, high efficient and green metholodology alternative was offered to extract anthocyanin from food matrices.

Effect of enzymatically hydrolyzed potato powder on quality characteristics of stirred yogurt during cold storage

This study evaluated the effect of supplemented enzymatically hydrolyzed potato powder (EHPP) for quality characteristics and the storage stability of stirred type yogurt in refrigerator storage. Six treatments of varying quantity of EHPP and whole milk powder (WMP) along with one control were prepared. The results revealed that the addition of EHPP significantly (p < .05) increased water holding capacity (WHC) and acidity, while pH and rheological properties (storage modulus and loss modulus) were decreased in comparison with control yogurt. However, treatment with 25 g EHPP/100 g WMP having 3% sugar (T4) improved physicochemical, textural, and rheological properties of stirred yogurt. The study presented the successful addition of the EHPP as ingredient for a new dairy product with ameleiorated functional and sensorial characteristics. However, a high amount of EHPP can negatively affect the desirable characteristics, especially WHC, texture, and rheological properties. Sensory scores including taste appearance and overall acceptance showed reduction trend in samples containing a high level of EHPP. The sensory analysis revealed that the optimized product showed better acceptability when compared with control yogurt during storage. The results suggested that an optimized product containing 25 g EHPP/100 g of WMP with 3% sugar (T4) has the potential for developing a new dairy product with high values added and consumer acceptance. Practical applications It is recommended that the addition of enzymatically hydrolyzed potato powder (EHPP) increases the yogurt acceptability which could be scaled up further at commercial scale, providing a reference for dairy products with the addition of starch-based ingredients as well as added market value because of potential functional properties of potato powder. The storage stability analysis revealed that the product could be used up to 21 days with preserved taste, aroma, and other quality characteristics without any additional preservative. Moreover, the novel EHPP not only improves the quality but also has numerous health benefits after combining with milk powder proteins.This study also highlights on the increased consumer’s acceptability and prolonged commercialization of dairy products.

The quest for reusability: The facile and stable immobilization of papain on cysteine functionalized iron oxide nanoparticles activated glass surface

The study displays the immobilization of papain on cysteine functionalized iron oxide nanoparticle coated glass beads. Glass beads were treated with (3-mercaptopropyl) trimethoxysilane and iron oxide nanoparticles capped with cysteine, to create a layer of cysteine on the surface of glass bead. This functionalized glass bead surface was further used to immobilize papain through glutaraldehyde treatment. The average size of cysteine capped iron oxide nanoparticles were found to be 50 nm. The binding of cysteine through the iron oxide nanoparticles was validated by Fourier transform infra-red spectroscopy. The activity of enzyme was found to be stable at variable temperature and pH conditions. The covalently immobilized enzyme on the glass bead sustained high enzyme activity and could be reused for 5 times without losing its activity. The immobilized papain retained 81% of its initial activity after 5 consecutive cycle. The storage stability analysis of the immobilized system revealed that it is stable for 6 months without loss in its activity. An average of 1.8 mg papain was successfully immobilized per gram of glass beads. In this case cysteine emerges as a new and effective medium for immobilizing biomolecules as it provides high efficiency towards immobilization.

Hydrothermal liquefaction of Chlorella pyrenoidosa and effect of emulsification on upgrading the bio-oil

This work studied the hydrothermal liquefaction of Chlorella pyrenoidosa and effect of emulsification on upgrading the bio-oil. The fuel properties and storage stability characteristics of emulsion fuels were explored. The combustion characteristic analysis showed that the ignition temperatures of emulsion fuels (139.6–151.3 °C) were lower than that of bio-oil (176.9 °C). Besides, emulsion fuels had higher comprehensive combustion indexes (7.24–14.08 × 10−6 × min−2 × C−3) than bio-oil (1.51 × 10−6 × min−2 × C−3), indicating that emulsion fuels had better combustion performance. The kinetic analysis showed that emulsification could effectively reduce the activation energy, resulting in less energy input for combustion. Based on chemical composition evolution during the storage process, a possible stability mechanism was proposed. The storage stability analysis indicated that the diesel-solvable fractions in bio-oil had better stability. Overall, this work provides a feasible way for bio-oil upgrading through emulsification. In addition, a better understanding of the stability property of emulsion fuel was provided.

SPR nanosensor based on molecularly imprinted polymer film with gold nanoparticles for sensitive detection of aflatoxin B1

Aflatoxins which are highly toxic, immunosuppressive and carcinogenic secondary metabolites produced naturally by Aspergillus flavus fungal species have a harm effect on human and animal health. Label free and rapid sensing of aflatoxin B1 (AFB1) has drawn the increased interest of highly sensitive and selective research. A highly sensitive and selective plasmonic sensing method was developed for the detection of AFB1 based on enhance-surface plasmon resonance nanosensor. Firstly, AFB1 and N-methacryloyl-l-phenylalanine were pre-complexed as a template molecule and functional monomer. Molecularly imprinted polymers with gold nanoparticles were coated onto surface plasmon resonance (SPR) gold chip surface. The AFB1 imprinted nanosensor shown a wide linear range, between 0.0001 ng mL−1 and 10.0 ng mL−1, and the limit of detection is 1.04 pg mL−1. Compared to the non-imprinted nanosensor, the imprinting factor was found to be 5.91. Also, detection studies of AFB1 were performed using various food samples. Finally, SPR nanosensors were performed selectivity, reusability and storage stability analysis.

Degradation of Sesame Oil Phenolics Using Magnetic Immobilized Laccase

Phenolic compounds exhibit toxic effects and there are still many challenges to find an efficient way for degradation and removal of phenol especially from food. In the present study, magnetically immobilized laccase was prepared and applied as an efficient heterogeneous biocatalyst for biodegradation of phenol from sesame oil. Laccase was attached covalently to magnetic Fe3O4 nanospheres and nanorods, and the characteristics of the immobilized enzyme were studied. The magnetic supports were analyzed by scanning electron microscopy, X-ray diffraction, vibrating sample magnetometry, and Fourier-transform infrared spectroscopy. Storage stability analysis of immobilized enzyme showed that more than 70% of initial activity was kept after 15 days at 4 °C. More than 70% phenol degradation was achieved and a 60% decrease in the activity of immobilized laccase was observed after 20 independent cycles. The development of enzyme immobilization techniques on magnetic supports may expand the potential applications of heterogeneous biocatalysts in food industries.

SYNTHESIS AND OPTIMIZATION OF GEMCITABINE-LOADED MIL-101NH2 (Fe) NANOCARRIERS: RESPONSE SURFACE METHODOLOGY APPROACH

Objective: The objective of the present study is to synthesize and optimize gemcitabine (GEM)-loaded MIL-101NH2 (Fe) nanocarriers. The design of experiments is used to optimize the formulation for higher encapsulation efficiency (EE) for effective drug delivery.&#x0D; Materials and Methods: MIL-101NH2 (Fe) was synthesized by microwave-assisted hydrothermal method. Central composite design (CCD) under response surface methodology was used for the optimization of GEM encapsulation into the MIL-101NH2 (Fe). The most influential variable that affects the EE was investigated by Perturbation plot. Validation of the design was carried out by performing the experiments under optimal conditions. Further optimized formulation was physicochemically characterized for particle size, surface charge, and surface morphology using zetasizer and scanning electron microscopy (SEM), respectively. Structural integrity of the optimized formulation was carried out by Powder X ray crystallography (PXRD). Fourier-transform infrared (FTIR) spectroscopy was used for the confirmation of GEM loading. Accelerated storage stability analysis was also performed to find out the related parameters.&#x0D; Results: Here in this work, crystalline MIL-101NH2 (Fe) has been successfully synthesized by microwave radiation method. The optimization result revealed that process variables such as GEM concentration, pH, and time significantly affect the desired constraint, EE. Perturbation plot evidenced that among all the variables, pH is the most significant factor followed by drug concentration and time. The optimized formulation exhibited 76.4 ± 7% EE and average particle size of 252.9 ± 9.23 nm. PXRD and SEM results demonstrated that the optimized formulation was crystalline in nature. FTIR spectroscopy confirms the presence of drug inside the MIL-101NH2 (Fe). In vitro release profile revealed that MIL-101NH2 (Fe)-GEM exhibited the sustained release up to 72 h in comparison to the native GEM. Storage-stability studies also indicate that MIL-101NH2 (Fe)-GEM has a shelf life of 6 months.&#x0D; Conclusion: The EE of GEM in MIL-101NH2 (Fe) can be altered by varying the drug concentration and pH during the impregnation.

Production of highly uniform Pickering emulsions by novel high-intensity ultrasonic tubular reactor (HUTR)

The current work proposed an alternative ultrasound (US) technology, namely the high-intensity ultrasonic tubular reactor (HUTR) for preparing Pickering emulsions. Using the non-toxic and environmentally friendly cellulose nanocrystal (CNC) as a solid stabilizer, Pickering emulsions were produced using the HUTR and the results showed that Pickering emulsions as small as 1.5 µm can be produced using HUTR at the US power and sonication time of 300 W and 15 min respectively. Additionally, the sizes of Pickering emulsion obtained are found to remain the same upon 30 days of storage. The performance of HUTR in emulsion preparation is compared to conventional US horn system at the same US power. It was observed that the use of HUTR allowed generation of Pickering emulsion that is significantly smaller (around 7.40 μm) and with better droplet size distribution (Coefficient of variation, CV = 31%) as compared to those prepared with US horn method (12.75 µm, CV = 36%). This is owing to the better distribution of cavitation activity in the treatment chamber of HUTR as compared to those in the horn, according to the sonochemiluminescence (SCL) study. From the 30-days storage stability analysis, the CNC-PE prepared using HUTR was found to more stable against droplet coalescence in comparison to those prepared using US horn. Our findings suggested that the HUTR possessed superior Pickering emulsification capacity when compared to conventional US horn. Further work will be necessary to evaluate the feasibility of such intensifying tubular reactor technology for larger scale emulsification and other process intensification applications.

Stability studies of enzyme aided anthocyanin extracts from Prunus nepalensis L

Prunus nepalensis L. (Sohiong) is an important indigenous fruit crop in Meghalaya (India). The purple coloured fruit has high anthocyanin content which can be tapped for its colouring attributes and therapeutic benefits. Physicochemical characteristics, thermal and storage stability analysis of freeze dried extracts obtained by enzyme assisted extraction (EAE) and conventional solvent extraction (CSE) from P. nepalensis L. were investigated. The physicochemical characteristics, viz. colour (L, a, b and ΔE) and hygroscopicity, showed a significant (p ≤ 0.05) difference between the two extracts. Stability studies (temperature, pH and light) demonstrated that the extract obtained by EAE was comparatively more stable (p ≤ 0.05) than the extract obtained by CSE. These results indicate that enzyme assisted extraction can be used as an alternative method for extracting anthocyanins for potential applications in food industry as biocolourant besides improving the therapeutic index of food.

DESIGN, FORMULATION, AND CHARACTERIZATION OF LIPOSOMAL-ENCAPSULATED GEL FOR TRANSDERMAL DELIVERY OF FLUCONAZOLE

Objectives: The present objective for the study was to prepare proliposomal gel bearing an antifungal agent, fluconazole (FLZ) intended for topical application.Methods: Various proliposome formulations were prepared using thin-film hydration technique by varying the lipid phase composition (phosphatidylcholine/cholesterol). Proliposome formulations were characterized for vesicle size, vesicle size distribution, vesicle morphology, drug content, entrapment efficiency, percentage yield value, storage stability analysis, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), in vitro diffusion study, release kinetic studies, and antifungal activity. Topical proliposomal gels were prepared by incorporation of lyophilized proliposome into a structured vehicle carbopol 934 (2.5%).Results: A spherical shape of reconstituted FLZ liposome with an average vesicle about 5–8 μm was observed in photomicrographs. The percentage entrapment of drug was increased with increase in phospholipid composition in the range of 55.13–69.61%. The FTIR and DSC studies showed no possible drug-excipient interaction. Proliposomal gel showed the prolonged release of FLZ than the lyophilized liposomes. The release kinetic values of regression coefficients confirmed the diffusion-dependent release of the drug. Stability studies indicated that product is stable and should be stored at low temperature.Conclusion: The proposed FLZ proliposomal gel showed sustained release with enhanced antifungal activity implicating its potential in effective transdermal delivery for the topical pharmacotherapy.

Disruption of Phaffia rhodozyma cells and preparation of microencapsulated astaxanthin with high water solubility.

A novel process was developed for encapsulation of astaxanthin from Phaffia rhodozyma. The yeast cells were disrupted by glass beads and the high shearing force partially emulsified the astaxanthin in aqueous phase. The enzymolysis method was then adopted to prepare the yeast extract for a full use of the cells. The gelatin and porous starch were used to microencapsulate the emulsified astaxanthin. Under optimized conditions, the recovery of amino nitrogen and solid reached 3.68 ± 0.32% and 49.22 ± 2.34%, respectively. The microencapsulation conditions were optimized through orthogonal experiment and the encapsulation efficiency, loading astaxanthin, and amino-nitrogen reached 88.56%, 1.55mg/g, and 1.35 ± 0.14%, respectively. The water solubility of microcapsules reached 81.5 ± 0.35%. Color and storage stability analysis showed that microencapsulation of astaxanthin possessed higher thermal stability. The results demonstrated that the established process was effective and practical.

Effect of solvent ph, microwave power and extraction time on microwave-assisted extraction of hibiscus rosa-sinensis

The objectives of the study were to evaluate the effect of solvent extraction pH, microwave extraction power and time on the yield of total anthocyanin and colour of Hibiscus rosa-sinensis (H. rosa-sinensis) extract and to evaluate the storage stability of total anthocyanin content and antioxidant activity of these extracts during storage. The factors studied were solvent pH (1.0 and 4.0), microwave power (400 W and 800 W) and extraction time (1 min and 3 min). Results showed that the highest total anthocyanin extracted was 9.56 ±0.001 g cyanidin-3-glucoside when extraction was performed using solvent of pH 4 at 800 W and 3 min and followed by 8.33 ± 0.001 g cyanidn-3-glucoside using solvent of pH 2 at 800 W and 3 min. H. rosa-sinensis extract in pH 2 was in red while the extract in pH 4 was in dark red. For the 10 d storage stability analysis, H. rosa-sinensis extract of pH 2 and pH 4 at 800 W and 3 min were selected. During storage, the extract in pH 4 showed an increase in total anthocyanin content and radical scavenging inhibition percentage. On contrary, the total anthocyanin content and radical inhibition percentage for pH 2 extraction sample decreased during storage.

Dissolving polymer microneedle patches for rapid and efficient transdermal delivery of insulin to diabetic rats

This study presents a dissolving microneedle patch, composed of starch and gelatin, for the rapid and efficient transdermal delivery of insulin. The microneedles completely dissolve after insertion into the skin for 5min, quickly releasing their encapsulated payload into the skin. A histological examination shows that the microneedles have sufficient mechanical strength to be inserted in vitro into porcine skin to a depth of approximately 200μm and in vivo into rat skin to 200–250μm depth. This penetration depth does not induce notable skin irritation or pain sensation. To evaluate the feasibility of using these dissolving microneedles for diabetes treatment insulin-loaded microneedles were administered to diabetic rats using a homemade applicator. Pharmacodynamic and pharmacokinetic results show a similar hypoglycemic effect in rats receiving insulin-loaded microneedles and a subcutaneous injection of insulin. The relative pharmacological availability and relative bioavailability of insulin were both approximately 92%, demonstrating that insulin retains its pharmacological activity after encapsulation and release from the microneedles. Storage stability analysis confirms that more than 90% of the insulin remained in the microneedles even after storage at 25 or 37°C for 1month. These results confirm that the proposed starch/gelatin microneedles enable stable encapsulation of bioactive molecules and have great potential for transdermal delivery of protein drugs in a relatively painless, rapid, and convenient manner.