Mixture Of Glycerol Research Articles

Un recubrimiento comestible a base de colágeno prolonga la vida útil de tuna (Opuntia ficus indica) mínimamente procesada

The purpose of this research was to evaluate the effect of an edible coating formulated with a mixture of collagen and glycerol to prolong the shelf life of three varieties of minimally processed prickly pear under refrigerated conditions. In the first stage of the research, the raw material (prickly pears) was characterized physico chemically. In the second stage, a flow chart of the technological process of applying the edible coating was designed: reception of raw material, selection, and classification, washing and disinfection, cutting, immersion in edible coating, drying, packaging (PET) and storage (2 °C). In the third stage of the research, the study of the shelf life of the prickly pear was considered, storing the samples under refrigerated conditions for a period of 20 days, evaluating the variation in weight loss, °Brix, pH, titratable acidity percentage, firmness and vitamin C content, antioxidant activity and total polyphenols in prickly pear slices, using a 3x2 factorial statistical design which studied the effects of 2 factors in 9 runs, with 3 replications, concluding that the shelf life of minimally processed prickly pear is 12 days at 2 degrees temperature.

Biodegradable Packaging Made from Banana Peels

Given the increase in production, the excessive use of plastic, and the negative impact it has on the environment, sustainable alternatives are being sought to replace this material; that is why there is a great demand for the development of new materials that are friendly to our mother earth. The current work aims to prepare bioplastic sheets made from banana peel as the primary raw material. A mixture of glycerin, corn starch, and vinegar (acetic acid) was added, resulting in brown biodegradable containers and sheets, similar to the results of other research using this biological material, and with more time to show signs of deterioration compared to other bioplastics.

Predicting the Heat-Exchange Intensity in the Biogas Production

The intensity of the heat exchange between the internal thin-wall vessel and the experimental liquid medium has been studied. The mixture of the distilled glycerol, the substrate from the operating biogas plant, the fresh chicken manure with the moisture content of W = 90 %, chicken manure with the moisture content of W = 90 % aged for 5 days and the chicken manure with the moisture content of W = 90 % aged for 13 days was used as the experimental liquid medium. The experimental-calculative method was suggested to define the coefficient of the heat loss between the internal thin-wall vessel and the experimental liquid medium using the method of regular thermal mode. The main problems peculiar for the methods of the definition of the heat-exchange intensity in the multi-phase and multi-component media in the food industry and in the biogas production have been analyzed. The heat-exchange intensity prediction methods available for the food industry are of great importance for heat and power computations. These methods refute the characteristics of the media and it has a great effect on the computation of their thermal and physical properties. Food products subjected to the thermal processes of sublimation, evaporation, heating and crystallization have the properties of solid, liquid and gaseous bodies and transform from one aggregate state to another and it has a substantial effect on a change of their thermal and physical properties. Biogas technologies are used by the multi-tonnage production. These technologies use huge volumes of the substrate with unknown thermal and physical properties. Contemporary development of biogas technologies raises the problems relating to the thermal stabilization of the process and prediction of the heat-exchange intensity. The productions pay much attention to the problems of the stable temperature mode in the bioreactor. The operation of the biogas plant requires a stable temperature mode at different ambient temperatures. The main requirement to the bioreactor is that the temperature fluctuations should be within certain ranges. The waste treatment of different productions, in particular heating, cooling, thermal stabilization results in the anthropogenic load on the environment due to use of the outdated and not upgraded heat process equipment. It is rather difficult to solve this problem because the thermal and physical properties of the mixtures, liquids, substrates and their chemical compositions and molecular structure are limitedly known or unknown. It is also unknown how these are changed during the thermal treatment and how environmental factors affect their change. Relative errors of the main values, in particular the heat loss coefficient, heat transfer coefficient, specific heat capacity, heat exchange surface area, cooling (heating) rate, nonuniform temperature distribution factor, heat flow, temperature rush, temperature difference, mass of the experimental liquid media, experiment duration and table values have been determined.

Ag+ ion in choline chloride and glycerol mixture: Evaluation of electrochemical properties and molecular modelling approaches

The thermodynamic and electrochemical properties of the silver ions (Ag+) dissolved in choline chloride (ChCl) and glycerol (G) mixture at eutectic composition were investigated. In addition, a computational calculation was carried out using Molecular Dynamic (MD) and Density Functional Theory (DFT) methods to understand the prevailing interactions in the investigated system. Specific mass, speed of sound, viscosity, and refractive index were measured at temperatures between 293 and 343 K and 101.3 kPa. The electrochemical behavior of Ag+ ions was analyzed by cyclic voltammetry in the range of 313 and 343 K. Silver coatings were successfully electrodeposited on the gold (Au) surface without adding additives to the electroplating solution. Scanning Electron Microscopy (SEM) analyzed the surface morphologies of the electrodeposits. The computational calculation indicated that adding silver nitrate to the eutectic solvent provided a predominance of repulsive forces for 1ChCl:2G and had negligible influence on sound velocity and refractive index. Finally, MD simulations showed a strong interaction between the Ag+ ions with the Cl− ions.

Synthesis and Characterization of Banana Peel Starch-based Bioplastic for Intravenous Tubes Preparation

The work undertaken in this paper intends to reduce the negative environmental effects of single-use plastics especially to trim down the medical waste generated post-utilization of plastic intravenous tubes. The present study emphasises on the production, characterization of banana peel starch-based bioplastic with Glycerin as bioplastic adhesive or plasticizer. Single-use plastic medical wastes derived from petroleum-based sources continue to accumulate in landfills and leach into the environment. Managing plastics and medical wastes tends to be an urgent environmental crisis and poses a serious threat to the same, and switching to biodegradable plastics can help to alleviate the problem. Three assorted banana peel starch-based bioplastic samples were fabricated using assorted mixtures of Banana peel starch, Corn starch, Vinegar, Glycerin and distilled water. All the three samples were subjected to evaluation tests such as moisture content, water absorption, water solubility, alcohol solubility, Soil degradation, tensile strength study and FTIR analysis. In addition, the intravenous tube was simulated using ANSYS software, and its flow and velocity profiles were studied and tested. Obtained results evince that banana peel starch-based bioplastic sample-II has the necessary physiochemical and mechanical properties, which may be printed and moulded as intravenous tube in future, for infusion and transfusion applications.

Karakteristik Pola Aliran Air-Udara, Campuran Air+Gliserin (G20)-Udara, dan Campuran Akuades+Butanol 4%-Udara Pada Pipa Horizontal Berukuran Mini

This study aims to obtain information about the flow characteristics of Water-Air Flow, Mixture of Glycerin+Water(G20)-Air, and Mixture of Aquadest+Butanol 4%-Air. The two-phase flow characteristics in mini-sized pipes have significant differences with the two-phase flow characteristics in conventional pipes, so it will affect fluid distribution processes involving two-phase flow such as heat transfer processes. Therefore, it is necessary to conduct further studies on the two-phase flow pattern in mini-sized pipes. This research was conducted in a test section in the form of a glass pipe with a diameter of 1.6 mm in a horizontal position. The liquid fluid used is water which has a surface tension (σ) of 71 mN/m, a mixture of glycerin+water (G20) has a surface tension (σ) of 62.5 mN/m, and a mixture of distilled water+butanol 4% has a surface tension (σ) of 36.50 mN/m. Superficial velocity of gas (JG)=0.033–4.935 m/s, and superficial velocity of liquid (JL)=0.025–66.3 m/s. The results showed that stratified flow was not observed in the mini channel as can be found in conventional pipes. The detected flow patterns are: bubbly, slug, slug-annular, churn, and annular. The results of flow pattern maps compared with flow pattern maps from Triplett et al (1999a), Chung and Kawaji (2004) and Sudarja et al (2014), and Aqli et al (2015) show that the higher the viscosity, the higher the annular churn-slug flow transition line will be. decreases while the annular – slug annular transition line tends to be more sloping.

On the Stability of Particle–Particle Interaction during Gravitational Settling

The elevated energy demand and high dependency on fossil fuels have directed researchers’ attention to promoting and advancing hydraulic fracturing (HF) operations for a sustainable energy future. Even though previous studies have demonstrated that the proppant suspension and positioning in slickwater play a vital role during the shut-in stage of the HF operations, minimal experimental work has been conducted on the fundamental proppant–proppant interaction mechanisms, especially a complete mapping of the interactions. This study utilizes high-speed imaging to provide a 2D space- and time-resolved investigation of two-particle (proppant models: 2 mm Ø, 2.6 g·cm−3) interactions during gravitational settling in different initial spatial configurations and rheological properties. The mapping facilitates the identification of various interaction regimes and newly observed particle trajectories. Pure water results at a settling particle Reynolds number (Rep) ~ 470 show an unstable particle–particle interaction regime characterized by randomness while altering pure water to a 25% (v/v) water–glycerin mixture (Rep ~ 200) transitions an unstable interaction to a stable prominent repulsion regime where particles’ final separation distance can extend up to four times the initial distance. This indicates the existence of Rep at which the stability of the interactions is achieved. The quantified trajectories indicate that when particles are within minimal proximity, a direct relation between repulsion and Rep exists with varying repulsion characteristics. This was determined by observing unique bottle-shaped trajectories in the prominent repulsion regimes and further highlighted by investigating the rate of lateral separation distance and velocity characteristics. Additionally, a threshold distance in which the particles do not interact (or negligibly interact) and settle independently seems to exist at the normalized 2D lateral separation distance.

Optimization of the Formulation of Sago Starch Edible Coatings Incorporated with Nano Cellulose Fiber (CNF)

This study aimed to produce new edible coatings based on the mixture of sago starch, cellulose nanofiber (CNF), glycerol, and tween-80.The effect of sago starch (5–10 g of starch/100 ml of distilled water), CNF (0.5–20% w/w), glycerol (10–30% w/w), and tween-80 (0.5–10% w/w) based on sago starch concentration on contact angle (CA), water vapor permeability (WVP), oxygen permeability (PO2) and tensile strength (TS) properties of the edible coatings were optimized using factorial experimental design (2k).The result showed that the linear model for all independent variables was significant (<i>P</i><0.05) on all responses (dependent variable).The sago starch concentration depicted a significant (p < 0.001) positive effect on contact angle; CNF showed a statistically significant effect on WVP, PO2, and TS; tween-80 showed a significant effect on all dependent variables, whereas glycerol only affected WVP. The optimum concentrations of sago starch, CNF, glycerol, and tween-80 were predicted to be 5 g/100 ml distilled water, 20% w/w, 10% w/w, and 0.5% w/w based on sago starch, respectively to obtain the minimum contact angle, WVP, PO2, and the maximum TS. The predicted data for the optimized coating formulation were in good agreement with the experimental value. This work revealed that the potential of sago starch/CNF based coating formulation could be effectively produced and successfully applied for coating of food.

Synthesis of a new hydrophobic coating film from stearic acid of buffalo fat

This experiment involved the chemical conversion of pure stearic acid from buffalo adipose tissue to a waxy stearyl stearate, which was subsequently applied as a coating film to extend the shelf life of recently harvested fruits. Fat was extracted from minced adipose tissue using the dry rendering procedure, and it was then characterized. The extracted fat was hydrolyzed into a mixture of free fatty acids and glycerol. The supercritical CO2 extractor was used for stearic acid individual extraction in pure form from the free fatty acid mixture, and it was confirmed according to its melting point (69.2–70.0 °C), elemental analysis, GC–MS for esterified fatty acids. The isolated stearic acid was used for the synthesis of a new hydrophobic wax named stearyl stearate. The chemical structure of the prepared compound was established according to its elemental analysis and spectral data. The new hydrophobic wax was used as a coating film to enhance the shelf life of freshly harvested tomato fruits. Therefore, stearyl stearate solution (2.00% w/v diethyl ether) was used for tomato coating and compared to chitosan-coated tomatoes, where weight loss, pH, fruit firmness, ascorbic acid concentration, and total soluble solids were studied for a period of 15 days at 23 ± 1.0 °C and 65 ± 2.0% relative humidity. The results revealed that coating with stearyl stearate solution (2.00% w/v diethyl ether) could delay tomatoes’ ripening during the experiment condition. A sensory evaluation of the coated tomatoes was carried out and showed acceptable taste for the tomatoes that were coated with stearyl stearate. On the other hand, the acute oral toxicity of stearyl stearate using albino mice showed complete safety up to 25 g/kg mice weight.

Composites of thermoplastic starch/natural rubber blends for fertilizer-releasing in agriculture

Thermoplastic starch (TPS) based on the mixture of cassava starch and glycerol was prepared and blended with the natural rubber (NR) and epoxidized NR (ENR). The resulting blend was further filled with fertilizer grade 16–16–16. The effects of fertilizer concentration on the properties of the blends and the growthability of maize seedling were investigated and characterized. In case of the specific properties of the blends, it was found that the blends based on NR and ENR matrices exhibited a reduction in tensile properties upon increasing the fertilizer concentration, while the solubility, water absorption and biodegrability were improved. In particular, the blends of TPS/ENR with fertilizer showed better properties than that of the blend with NR due to the physical interaction of hydrogen bonding among the polymer molecules as confirmed from ATR-FTIR. Although both the blends were found to be decomposed within a period of two weeks, the releasing efficiencies significantly affected the growth of maize seedlings. According to the growthability based on count and greenness of leaves, shoot and root biomasses and phytotoxicity of fertilizers, the TPS/ENR with 80 phr of fertilizer represented the suitable one for growing the seedlings with proper release ability of fertilizer, especially the N, P and K elements during planting. Relating the water swelling of 180 %, it was found that the approximately 90 % of N, 70 % of P and 95 % of K were released before the complete decomposition degradation. This newly controlled release fertilizer (CRF) system can be applied for several plants by knowing the fertilizer concentration and ease of shape designing.

Experimental study of influence of liquid viscosity in horizontal slug flow

Slug flow is present in many industrial processes, including the ones related to the petroleum industry. Such flow pattern is characterized by the periodic passage of liquid slugs that may or may not be aerated and elongated bubbles that flow atop a liquid film. Most of the existing models for slug flow have been developed for two-phase water–air flows but, in oil and gas production, the liquid phase is often substantially more viscous than water. The aim of this article is to evaluate the effect of the liquid viscosity increase on slug flow. To achieve this goal, an experimental study on liquid–gas flows in a 26-mm ID, 8.65-m long horizontal pipe was developed. Water and mixtures of water and glycerin (μL≈5.46, 10.27, 15.39, 20.33 and 30.37 cP) made the working liquids. The experimental results from the high-speed camera and resistivity sensors enabled a detailed investigation of elongated bubble characteristics and slug flow parameters. The elongated bubble nose deformation, the appearance of plunging jets and the deformation of the dispersed bubbles are associated to dimensionless numbers. Experimental results show that the dispersed bubble deformation in the slug, the number of fragmented bubbles in the slug and the elongated bubble velocity increase as the mixture velocity and the liquid viscosity increase. The effects on the slug frequency and slug length depend on the superficial velocities of the fluids.

Application of residual cooking oil to improve the production of a low-toxic biosurfactants extract

Residual cooking oil (RCO) bioconversion into value-added products is one of the best options to manage this waste. Thus, the feasibility of producing lipopeptides by Pseudomonas syringae pv tabaci using this residue is reported for the first time. Surface activity, stability, and cytotoxicity of biosurfactants were explored by surface tension, emulsification indexes (EI24), and mammalian cell viability assays. It was demonstrated that a mixture of RCO and glycerol (1:1) as carbon source increased the production titer from 1.47 to 2.70 g/L, syringopeptin being the main component. The produced lipopeptides were able to reduce the water surface tension down to38 mN/m and emulsify effectively (EI up to 67 %) a wide variety of hydrophobic compounds at 0.10 g/L. Moreover, these lipopeptides at 1.0 g/L resulted to be highly compatible with mammalian cells (viability superior to 70 %), demonstrating that at the working concentrations are non-toxic and thus, adequate for food and pharmaceutical applications.

"EVALUATION OF PHYTOTOXICITY AND BIODEGRADATION OF CELLULOSE REINFORCED STARCH BIOCOMPOSITES "

With increasing environmental pollution, sustainable alternatives for packaging materials are important. This study aimed to evaluate the phytotoxicity and biodegradation of corn starch films reinforced with cellulose extracted from pineapple crowns. The films were produced by casting mixtures of corn starch, glycerol and cellulose at different concentrations (5%, 10% and 15%), along with a pure starch control film. The phytotoxicity assay showed that the addition of films to the soil does not negatively influence the germination and growth of lettuce seeds (Lactuca sativa). In the biodegradation assay, the films were completely degraded after 60 days, especially the film containing 15% cellulose, which experienced rapid biodegradation, with a high rate of initial mass loss. Analysis of the Fourier transform infrared (FTIR) spectra after degradation of the films showed no structural changes. These materials have no harmful effects on the environment and have great potential for application as rapid-use packaging.

Effective Thermal Conductivity of Nanofluids Containing Silicon Dioxide or Zirconium Dioxide Nanoparticles Dispersed in a Mixture of Water and Glycerol

The present study investigates the effective thermal conductivity of nanofluids containing crystalline or amorphous silicon dioxide (SiO2), or zirconium dioxide (ZrO2) nanoparticles dispersed in a mixture of water and glycerol with a mass ratio of 60:40. Such fluids are relevant as potential cutting fluids in tribology and feature a broad distribution of irregularly shaped non-spherical particles of dimensions on the order of (100 to 200) nm that were produced by comminution of larger particles or particle aggregates. A new steady-state guarded parallel-plate instrument was applied for the absolute measurement of the effective thermal conductivity of the nanofluids with an expanded uncertainty (coverage factor k = 2) of 3% for temperatures from (293 to 353) K and particle volume fractions up to 0.1. For a constant volume fraction of 0.03 for the three particle types, the measured thermal-conductivity ratios, i.e. the effective thermal conductivity of the nanofluids relative to the thermal conductivity of the base fluid, are less than 1.05 and not affected by temperature. In the case of the nanofluids with crystalline SiO2, with increasing particle volume fraction from 0.03 to 0.10 the thermal-conductivity ratios increase up to values of about 1.18 for all temperatures. A comparison of the measurement results with the Hamilton-Crosser model and an analytical resistance model for the effective thermal conductivity of nanofluids shows that the former one allows for better predictions for the present nanofluids with a relatively large viscosity. In this context, it could be shown that detailed knowledge about the sphericity and thermal conductivity of the dispersed nanoparticles is required for the modeling approaches.

Production of Polyhydroxyalkanoates through Soybean Hull and Waste Glycerol Valorization: Subsequent Alkaline Pretreatment and Enzymatic Hydrolysis

Alkaline pretreatment and sequential enzymatic hydrolysis of soybean hull were investigated to obtain fermentable sugars for polyhydroxyalkanoates production along with residual glycerol as low-cost carbon sources. Soybean hull is composed of approximately 32% cellulose, 12% hemicellulose, 6% lignin, and 11% protein. Alkaline pretreatment was carried out with 2% NaOH concentration, 10% (w/v) biomass loading, and 60 min incubation time in an autoclave at 120 °C. The response surface methodology (RSM) based on the central composite design (CCD) tool was employed to optimize the enzymatic hydrolysis process, where the variables of biomass loading, enzymes’ concentration, and time were considered. The maximum total reducing sugars concentration obtained was 115.9 g∙L−1 with an enzyme concentration of 11.5 mg protein/g dry substrate for enzyme preparation B1, 2.88 mg protein/g dry substrate for XylA, and 57.6 U/g dry substrate for β-glucosidase, after 42 h at 45 °C, and pH was 4.5. Subsequently, the saccharification step was conducted by increasing the processing scale, using a 1 L tank with stirring with a controlled temperature. Implementing the same enzyme concentrations at pH 4.5, temperature of 45 °C, 260 mL working volume, and incubation time of 42 h, under fed-batch operation with substrate feeding after 14 h and 22 h, a hydrolysate with a concentration of 185.7 g∙L−1 was obtained. Initially, to verify the influence of different carbon sources on Cupriavidus necator DSMz 545 in biomass production, batch fermentations were developed, testing laboratory-grade glucose, soybean hull hydrolysate, and waste glycerol (a by-product of biodiesel processing available in large quantities) as carbon sources in one-factor-at-a-time assays, and the mixture of soybean hull hydrolysate and waste glycerol. Then, the hydrolysate and waste glycerol were consumed by C. necator, producing 12.1 g∙L−1 of biomass and achieving 39% of polyhydroxyalkanoate (PHB) accumulation. To the best of our knowledge, this is the first time that soybean hull hydrolysate has been used as a carbon source to produce polyhydroxyalkanoates, and the results suggest that this agro-industrial by-product is a viable alternative feedstock to produce value-added components.

Effect of Electrical Conductivity on Atomization Characteristics of Electrospray

This study experimentally investigated various spraying modes in electrospraying, an atomization method in which a high voltage is applied to the auxiliary device at the tip of the nozzle. The spraying modes were generated depending on the experimental parameters (voltage, current, and flow rate) and characteristics of two test solutions (S and C), which were a mixture of ethanol, glycerol, citric acid, and water. Solution C had a higher electrical conductivity than solution S. Eleven spray modes were identified in the study. From a comparison of the spray modes, a maximum Sauter mean diameter (SMD) of the cone jet of solution S was 1.7 times that of solution S. The standard deviation of SMD for the unstable, rotating-jet, and pulsed-jet modes were more than two times that for the cone-jet mode. With an increase in flow rate in the cone jet, the SMD and SMD standard deviation of solution C increased linearly, and the SMD value of solution C was ~5% lower than that of solution B. The SMD standard deviations for both S and C solutions were small at low flow rates, and the standard deviation for solution C (with high conductivity) was smaller than that of solution S. For a given SMD, the current associated with solution C was higher than that associated with solution S. The study presented the comprehensive data for SMD, SMD standard deviation, and current in an electrospray system for the two fluids of different electrical conductivities under various experimental conditions.

Motion-based microwave tomographic measurement device for three-dimensional coverage in a magnetic resonance system.

We have developed a fully 3D data acquisition system for microwave breast imaging which can operate simultaneously inside a magnetic resonance imaging (MRI). MRI is used regularly for breast imaging to distinguish tumors from normal tissue. It generally has poor specificity unless used with a gadolinium contrast agent. Microwave imaging could fill this need because of the good endogenous tumor:normal tissue property contrast, especially in light of safety concerns for gadolinium. The antenna array consists of 16 monopole antennas positioned in a horizontal circle surrounding the breast which can then be moved vertically for 3D coverage of the breast. The tank system materials were chosen to minimize artifacts in the MR image within the specific shared imaging zone. The support rods are stainless steel, albeit positioned sufficiently far from the imaging target to have little effect. The mechanical motion parts are all 3D printed plastic. Unlike many conventional antennas, the monopoles consist of just the center conductor and insulator of the coaxial cable, making it one of the least possible metallic structures. Data were acquired both inside and outside of the MR bore to confirm that the MR bore did not have adverse effects on the microwave imaging process. The imaging tank was filled with a mixture of glycerin and water to both provide a reasonable property match to the phantom and to highly attenuate the fields which also acted to suppress multi-path signals. Microwave images were reconstructed using our Gauss-Newton scheme combined with a log transformation for a more linear convergence. MR images were also acquired to assess the effects of the microwave tank structures on the imaging. The microwave measurement data were acquired in log magnitude and phase format at 200 MHz increments from 700-1900 MHz. Each antenna acted sequentially as a transmitter while the complement of 15 acted as a receiver. The single frequency images were reconstructed using a Gauss-Newton iterative technique with a standard log transformation to linearize the process. The data showed that the signal strengths were between 7-10 dB lower for the case when the array was inside the MRI versus when not. Notwithstanding, the image quality was still high because of the significant signal to noise ratio. The reconstructed images in both situations demonstrated good 3D object recovery of the vertically size and shaped varying object. The MR images were not adversely affected by the presence of antennas or feed structures. We have demonstrated that our technique can recover high-quality images of a 3D varying object within an MRI system. Compatibility issues have been addressed for both the microwave and MRI systems. The reduced SNR for the case operating in the MRI did not adversely affect the images. To the best of our knowledge, this is the first example of a microwave imaging system operating in an MRI with full 3D volumetric capability.

Production and Characterization of Edible Film from A Mixture of Tapioca Flour, Yellow Pump (Cucurbita moschatal D), Chitosan, and Glycerine for Application as A Layer Cake Packing.

The experiment of production and characterization of an edible film by mixing tapioca starch, pumpkin (Curcubita moschatal D.), chitosan, and glycerine with applications as the wrapping of layer cake has been done. The edible film was produced by mixing 2.5 g of tapioca starch, 3.5 g of pumpkin, and 40 mL of aquadest, then adding 4 % of chitosan, and 2 mL of glycerine. After homogenous, it was poured into an acrylic pan and dried in an oven at 35-45°C degrees for 2 days. Characterization of an edible film physically obtained thickness was 0.25 mm, tensile strength was 0.06 kgF/mm2 and elongation was 22.77 %. Morphology test of SEM (Scanning Electron Microscopy) produces edible film have pores that were tight, flat, and a bit compatible surface. And the FT-IR spectrum analysis showed the spectrum at 2939.52 cm-1 for the Alkana group (CH) and 3402.43 cm-1 for the hydroxyl group (OH). The result of the nutrition analysis of edible film was 28.2 % of carbohydrate content, 8.23 % protein content, 1.49 % of fat content, 25.6 % of water content, and 0.36% of ash content. An edible film can also be used as a wrapping for a layer cake.

Selection and Optimization of Medium Components for the Efficient Production of L-Asparaginase by Leucosporidium scottii L115—A Psychrotolerant Yeast

This study reports the production of L-asparaginase (ASNase), an enzyme mainly used for the treatment of acute lymphoblastic leukemia, by Leucosporidiumscottii L115, a psychrotolerant yeast isolated from the Antarctic ecosystem. Focus was given to select the most appropriate medium components able to maximize the enzyme production by this yeast, as a first step for the development of a new process to produce ASNase. By combining knowledge in bioprocesses, statistical analysis and modeling, the medium composition that most favored enzyme production was established, which consisted of using a mixture of sucrose (28.34 g L−1) and glycerol (15.61 g L−1) as carbon sources, supplemented with proline (6.15 g L−1) and the following salts (g L−1): KCl, 0.52; MgSO4·7H2O, 0.52; CuNO3·3H2O, 0.001; ZnSO4·7H2O, 0.001; and FeSO4·7H2O, 0.001. By using this medium, enzyme production of 2850 U L−1 (productivity of 23.75 U L−1 h−1) was obtained, which represented a 28-fold increase in enzyme production per gram of cells (178 U gdcw−1) when compared to the control (non-optimized medium), and a 50-fold increase when compared to a reference medium used for ASNase production.

Effects of organic carbon sources on growth and oil accumulation by Desmodesmus subspicatus LC172266 under mixotrophic condition.

Energy crisis and environmental sustainability have attracted global attention to microalgal biofuels. The present study investigated the impact of organic carbon sources on growth and bio-oil accumulation by an oleaginous microalga Desmodesmus subspicatus LC172266 under mixotrophic culture condition. Glucose and glycerol supported higher growth rates and lipid productivities than sucrose, fructose, mannitol and acetate. Each of the organic carbon source tested supported significantly (P < 0.05) higher growth rates and lipid productivities than the photoautotrophic culture (without organic carbon source). The lipid productivity obtained with a mixture of optima concentrations of glucose and glycerol (5.0gL-1 glycerol + 10.0gL-1glucose) (0.14875 ± 0.002g/L/day) was about 25% and 66% higher than the values obtained with only 10.0gL-1glucose and 5.0gL-1glycerol, respectively. When a batch culture with 5gL-1glycerol was fed with 0.5gL-1glucose daily the cell growth and lipid productivity were lower than the values obtained in a batch culture with a mixture of glucose and glycerol. The lipid productivity obtained in a 4-L photobioreactor was 94% (0.217gL-1day-1), higher than the value obtained in a flask culture with 10.0g/Lglucose (0.112gL-1day-1) and 46% higher than the value obtained in a flask culture with 5.0gL-1glycerol (0.086gL-1day-1).