Concentration Of Chitosan Solution Research Articles

Enhancing hemp fiber performance: insights into chitosan treatment and structural evolution

Hemp fiber, recognized for its eco-friendliness, wide availability, and biodegradability, stands as a renewable resource with promising applications. To fully harness its potential, it is crucial to study the relationship between chitosan concentration and both the mechanical and thermal properties of hemp fiber. Understanding these effects can provide a direction to improve the properties and functionalities of hemp fiber, which are essential for many applications, including textiles and construction and automotive materials. Chitosan is known to enhance the antimicrobial and adsorption properties of fibers by changing the chemical properties of the fiber surface. However, up to now, a very limited number of studies have focused on the exact effect of chitosan on the mechanical and thermal stability properties of hemp fibers. Here, the effect of treatment with different concentrations of chitosan solutions is investigated to enhance the properties of hemp fibers and the treated hemp fibers are characterized. It is found that chitosan solution treatment can effectively improve the various properties of hemp fibers. The chitosan treatment improved the surface roughness of hemp fibers. The tensile strength and flexibility of hemp fibers were enhanced. The CSHF-1.5% sample exhibited the highest tensile strength of 616.11 MPa and the lowest tensile modulus of 15.61 GPa. The fiber swelling rate increased to 24.73% at a chitosan solution concentration of 1.5%. The results of thermogravimetric analysis and differential scanning calorimetry analysis demonstrated the effectiveness of chitosan solution treatment in enhancing the thermal stability of hemp fibers. These findings propose a promising method for a significant modification of hemp fiber's mechanical and thermal stability.

Tunable evaporation-induced surface morphologies on chitosan film for light management

The surface morphologies of polymer films have been used to improve the performance or enable new applications of films, such as controllable adhesion, shape morphing and light management. However, complicated and destructive methods were applied to produce surface morphologies on chitosan (CS) film. To overcome this challenge, we report an evaporation-induced self-assembly to form the tunable morphologies on the surface of short-chain chitosan film by varying the evaporation rates that influence the aggregation behavior of polymer chains between order and disorder. It enables the simple, tunable and scalable fabrication of surface morphologies on CS film (CS solution concentration: 2 wt%, drying from room temperature (RT) to 80 °C) that provides controllable haze (3–74 %) and high transmittance (>85 %) for the production of hazy and transparent window coatings. This simple approach to producing tunable surface morphologies could inspire the synthesis of multifunctional polymer films with different surface structures, whose applications can be extended to cell culture interfaces, flexible bioelectronic and optoelectronic devices.

Abstract 3188: Chitosan-glycerol injectable gel for intratumoral retention of immunotherapeutics

Abstract A novel, injectable chitosan-glycerol hydrogel was developed and characterized. Upon injection with co-formulated therapeutics, the gel vastly improved molecule retention at the injection site, as compared to molecule delivery in less viscous media. Methods. The hydrogel was formed through a centrifugation process. 70% deacetylated, medium viscosity chitosan was dissolved in 0.1M HCl. Glycerol was then added, followed by vortexing. Next, 1x PBS and 1M NaOH were added to neutralize the mixture, which induced gelation. After hydrogel centrifugation at 10,000 rpm for 5 minutes, a hydrogel was separated from precipitate. Several formulation parameters were tested, including chitosan:glycerol volume ratio, chitosan concentration, chitosan degree of deacetylation, and chitosan molecular weight. The retention of model therapeutics, formulated in hydrogel or saline vehicles, following injection in agar-based tumor phantoms was quantified via absorbance and fluorescence readings. To assess biocompatibility, a non-contact cell viability assay was performed utilizing 3T3 fibroblasts seeded in the bottom of transmembrane wells with hydrogels added to the upper chamber. After 48 hours, cells were collected and counted utilizing trypan blue. New Data. A hydrogel for intratumoral therapeutic delivery was constructed with several desirable qualities, including biocompatibility and injectability through a 25-gauge needle. Different relative glycerol to chitosan volumes, from 5 to 95 w/v % glycerol, were tested to determine a range of gelation conditions. Glycerol volume most significantly impacted gelation conditions independent of chitosan concentration, with gelation occurring between 70-85% relative volume glycerol. Increasing chitosan solution concentration and chitosan molecular weight increased the range of chitosan:glycerol ratios resulting in gelation. The hydrogel improved load retention at the agar tumor phantom injection site for various sizes of model therapeutics compared to less viscous solutions. Cytotoxicity testing of the hydrogel showed a statistically insignificant difference between the live:dead cell ratios of the experimental and negative control groups. Conclusion. An injectable, biocompatible hydrogel was created through the neutralization and centrifugation of a chitosan-glycerol solution. The hydrogel displays physiological pH, injectability through a 25-gauge needle, biocompatibility, and vastly improved therapeutic load retention at the injection site compared to less-viscous delivery media. Chitosan-glycerol hydrogels may be useful for intratumoral delivery and retention of immunomodulators within the tumor microenvironment. Citation Format: Robert L. Kobrin, Siena M. Mantooth, David A. Zaharoff. Chitosan-glycerol injectable gel for intratumoral retention of immunotherapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3188.

Characterization of the sensing properties of zinc oxide chitosan as an acetone sensor

In this review, the characterization and detecting properties of chitosan/zinc oxide as an acetone sensor has been effectively done in view of the information of the experimental outcomes. . In this study the sensors were fabricated using electrodeposition methods where by chitosan solution concentration of 1.75 % was added with 0.1 %, 0.5 %, 1 %, and 1.5% zinc oxide. The detecting properties were done by uncovering acetone gas with grouping of 1 ppm, 5 ppm, 20 ppm 100 ppm and 200 ppm. The result shows chitosan sensing properties improved with the addition of zinc oxide. The highest response was exhibited from 0.5% zinc oxide when exposed with 100 ppm acetone while the lowest response generated from chitosan 1.75% for 1 ppm. This result attributed to the SEM characterization result of chitosan and chitosan/zinc oxide and bigger pores. Thusly, the expansion of zinc oxide further developed the detecting properties of chitosan as acetone sensor.

Antimicrobial Active Chitosan-Based Cotton Yarns: Effect of Chitosan Solution Concentration

Using the exhaustion-pad-dry-rinse method, chitosan was applied to alkaline-scoured and bleached cotton yarns in a solution with concentrations ranging from 0.2–1% to achieve good antimicrobial activity against the bacteria Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Studied samples were also assessed by measuring the amount of introduced chitosan, amount of accessible amino groups, mechanical properties, whiteness index and the b* colour coordinate. Alkaline-scoured and bleached cotton yarns treated with all concentrations of the chitosan solution showed good antimicrobial activity against Escherichia coli and Staphylococcus aureus. Better antimicrobial activity was achieved against Escherichia coli. Increasing the concentration of chitosan solution deteriorated the mechanical properties of chitosan-treated cotton yarns. The optimal concentration of chitosan solution incorporated in the exhaustion phase to obtain chitosan-treated yarns with good antimicrobial activity and mechanical properties was 0.6%. The best antimicrobial treatment should minimise potential economic costs while providing functionality.

The influence of chitosan on the raspberry quality during the storage process

Raspberry is a perishable berry raw material with a high capacity for mechanical and microbiological damage, and therefore, after harvesting, it is necessary to use appropriate technologies to preserve its quality and extend the storage time. This work aimed to study the influence of different concentrations of chitosan solutions on the quality and duration of storage of raspberries under refrigerating conditions. Raspberries were picked at the consumer maturity stage in perforated plastic containers with a capacity of 500 grams. The berries were processed by spraying with 0.5%, 1.0%, and 2.0% chitosan solution, then removing residual moisture. The storage was carried out for twelve days in a refrigerating chamber at a temperature of 2 °С and relative humidity of 95%. The research was performed according to the physical, chemical, and organoleptic indicators, determining the changes in the mass fraction of ascorbic acid, the mass fraction of sugars during storage, taste, aroma, colour, etc. consistency and appearance at the end of storage. It was found that the loss of ascorbic acid in the processed berries was 1.5-3.9 times less than in the reference sample. A similar situation was observed with the mass fraction of sugars, which prevailed 0.9-2.5 times in the processed samples. According to the organoleptic indicators, the samples with a solution concentration of 1.0% and 2.0% were recognized as the best. According to the results of experimental investigations, it was established that pre-processing of berries with chitosan solutions is a promising method to slow down unwanted metabolic processes that take place after harvesting.

Synthesis of Chitosan-Silver Nanocomposite and Its Evaluation as an Antibacterial Coating for Mobile Phone Glass Protectors.

An easy and environment-friendly route for antibacterial coating suited for mobile phone glass protectors was successfully demonstrated. In this route, freshly prepared chitosan solution in 1% v/v acetic acid was added with 0.1 M silver nitrate solution and 0.1 M sodium hydroxide solution and incubated with agitation at 70 °C to form chitosan-silver nanoparticles (ChAgNPs). Varied concentrations of chitosan solution (i.e., 0.1, 0.2, 0.4, 0.6, and 0.8% w/v) were used to investigate its particle size, size distribution, and later on, its antibacterial activity. Transmission electron microscope (TEM) imaging revealed that the smallest average diameter of silver nanoparticles (AgNPs) was 13.04 nm from 0.8% w/v chitosan solution. Further characterizations of the optimal nanocomposite formulation using UV-vis spectroscopy and Fourier transfer infrared spectroscopy were also performed. Using a dynamic light scattering zetasizer, the average ζ-potential of the optimal ChAgNP formulation was at +56.07 mV, showing high aggregative stability and an average ChAgNP size of 182.37 nm. The ChAgNP nanocoating on glass protectors shows antibacterial activity against Escherichia coli (E. coli) at 24 and 48 h of contact. However, the antibacterial activity decreased from 49.80% (24 h) to 32.60% (48 h).

Biosynthesis and characterization of chitosan nanoparticles, determination of its antifungal and antiaflatoxigenic against Aspergillus flavus isolates

Aflatoxin is a mycotoxin generated mostly by the fungus Aspergillus flavus, which may be found in food and feed. It is a carcinogenic poison for both humans and animals. The goal of this investigation was to see if toxicogenic A. flavus strains might be found on nuts in the Kurdistan Region. A total of Fifty nut samples. The colony color of A. flavus and texture were used to identify macromorphological qualities, whereas the spore color, size, structure, conidiophore structure, and vesicle shape were used to assess micromorphological properties. Direct imaging of the UV fluorescence of A. flavus colonies on coconut agar media (CAM) was used to detect aflatoxin formation. Natural compounds, such as chitosan, have been suggested as a way to prevent fungal infection because of their extensive and well-known antibacterial action against a variety of microorganisms. The goal of this entry was to morphologically characterize and determine aflatoxigenic A. flavus isolates, characterize nanoparticles using UV–visible, X-ray diffraction (XRD), Energy-dispersive X-ray (EDX), and scanning electron microscope (SEM) analyses, and determine the formulations' in vitro antifungal activity on the treated fungus. Individual concentrations were created by altering the percentages of ingredients such chitosan solution, chitosan nanoparticles, glycerol, and canola oil. The final concentrations of chitosan solution and chitosan nanoparticles were 20% and 2% respectively. Chitosan nanoparticles completely inhibit the growth of A. flavus at 2%.

Preparation, Physicochemical Properties, and Structural Characterization of Resistant Starch-Aspirin-Loaded Microspheres.

BACKGROUND Resistant starch is a novel type of dietary fiber that can be considered as a natural polymer carrier with potential development prospects in the field of oral colonic release preparations since it can be degraded by bacteria in the large intestine. MATERIAL AND METHODS In this study, oral resistant starch-drug-loaded microspheres were prepared by spraydrying, and the response surface method was used to optimize the process based on the encapsulation efficiency. RESULTS The optimal preparation process conditions for the resistant starch-aspirin-loaded microspheres were as follows: core material: wall material ratio of 1: 1.98, chitosan solution concentration of 1.98%, and spray drying air inlet temperature of 130.45°C resulted in a reliable entrapment efficiency of 68.96%. Infrared spectroscopy analysis indicated that the encapsulated aspirin-starch microspheres did not differ significantly from the original resistant starch material. The ultrastructure of the drug-loaded microspheres was evenly wrapped with the capsule core and appeared as smooth spheres. The combination of resistant starch, aspirin, and chitosan resulted in a cross-linking reaction that reduced the overall gelatinization temperature compared with the original starch material alone. The light transmittance of the drug-loaded microspheres was slightly higher than that of the original resistant starch, while digestibility was similar to that of the resistant starch, indicating that the release would exist in the environment of the large intestine. CONCLUSIONS This study provides pivotal insights into the development of resistant starch in the field of colonic release preparations.

INFLUENCE OF CHITOSAN ON THE QUALITY OF RASPBERRIES DURING REFRIGERATED STORAGE

Raspberries is a perishable berry with a high capacity for mechanical and microbiological damage, therefore, after harvesting, it is necessary to use appropriate technologies to preserve its quality and extend the shelf life. The aim of the research is influence of different concentrations of chitosan solutions on the quality and shelf life of raspberry berries under cooling conditions. Physico-chemical and organoleptic methods of research and methodological principles of collection, accumulation, systematization, analysis, generalization, and synthesis of information were used in the research. Raspberry berries were collected in the consumer stage of ripeness in perforated plastic containers with a capacity of 500 g. Processing of berries was carried out by spraying 0.5 %; 1.0 % and 2.0 % chitosan solution followed by removal of residual moisture. Storage was carried out for twelve days in a refrigerating chamber at a temperature of 2º C and a relative humidity of 95 %. The research was carried out by determining changes in the mass fraction of ascorbic acid, sugars during storage, as well as taste, aroma, color, consistency and appearance at the end of storage. It was established that the treated berries had 1.5–3.9 times less loss of ascorbic acid than in the control sample. A similar situation was observed with the mass fraction of sugars, the content of which prevailed by 0.9–2.5 % in processed raspberry samples. According to organoleptic indicators, samples with a solution concentration of 1.0 % and 2.0 % were recognized as the best. Raspberries not treated with chitosan quickly lost their marketable appearance, taste and aroma. It was found that pre-treatment of berries with chitosan solutions is a promising way to slow down undesirable metabolic processes during storage, which are carried out after harvesting, which practically makes it possible to extend the consumer properties of the product.

Comparative Study of the Synergistic Antimicrobial Efficacy of Chitosan with Chlorhexidine, Silver, and Propolis in Human Saliva

Purpose: The aim of the study was to evaluate and compare the synergistic antimicrobial effects of chitosan with chlorhexidine, silver, and propolis in human saliva. Materials and method: High and low concentrations of chitosan solution were prepared and added to the chlorhexidine solution, silver nitrate, and propolis extract. Antimicrobial testing was performed using colony-forming units (CFU) and disc diffusion tests with chitosan solution in both concentrations as a positive control. Biofilms containing Streptococcus mutans (S. mutans) were grown on 56 enamel blocks and subjected to the treatment solutions then diluted and grown on specific S. mutans media for colony counting. Inhibition zones were measured by immersing filter paper discs in the treatment solutions and incubating them on agar plates inoculated with S. mutans bacteria. Results: Statistical analysis showed that 5% chitosan/ nanosilver mixture (Chit/AgNps) had the highest synergistic antimicrobial effect in both tests with a mean value of (8.571 CFU/mL) for CFU and (44 mm) for disc diffusion. Conclusion: 5% Chit/AgNps showed the most promising antimicrobial efficacy against S.mutans among all mixtures.

THE EFFECT OF CHITOSAN SOLUTION ADDITION ON THE SIZE OF NANO CERAMIC PARTICLES IN ZrO2-Al2O3-SiO2 SYSTEM THROUGH BOTTOM-UP METHOD AS DENTISTRY RAW MATERIAL

Ceramics is a dental material used often because of its relatively good strength and aesthetic properties. Ceramics such as zirconia, alumina, and silica have different characteristics and have been synthesized using a bottom-up method separately. Recently, many studies have used chitosan solution to help synthesize nanometer-sized ceramic materials processed using the bottom-up method. This study aims to produce ZrO2-A12O3-SiO2 nanoparticle ceramics, which were synthesized simultaneously using the bottom-up method, and to see the effect of volume concentration of chitosan solution on the resulting ZrO2-A12O3-SiO2 ceramic particles. The composition ratio of ZrO2:Al2O3:SiO2 used is 3:1:1 with a concentration of 0.05M and a total volume of 500ml. The chitosan solution was added with a volume percentage of 0%, 5%, 10%, 15%, and 20%, respectively, and was named samples A, B, C, D, and E. The XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy) characterization of the five samples showed nano-sized particles, which were 87 nm, 85 nm, 81 nm, 76 ran, and 76 nm. SEM characterization results show that sample A's particle distribution is not very visible; the particle distribution is only seen in samples B, C, D, and E, while the best particle distribution is seen in sample C. This study concludes that the optimal volume concentration of adding chitosan solution to produce nano-sized ZrO2-A12O3-SiO2 ceramics with good particle distribution is 10% by volume percentage.

THE EFFICACY OF CHIOSAN FROM WINDU SHRIMP SHELLS AS A PRESERVATIVE OF FRESH KENYAR FISH IN THE FORM OF DARNE DURING STORAGE AT ROOM TEMPERATURE

This study is about the efficacy of chitosan from windu shrimp shells (Panaeus monodon) as a preservative for fresh fish in the form of darne (steak), namely fresh kenyar fish (Sarda orientalis) during storage at room temperature. The chitosan solution used are chitosan solution with concentration of 1%, 1.5%, 2%, and 2.5%. The fish samples which soaked in that solutions are named T1, T2, T3, and T4, respectively .. The soaking time were 20, 40 and 60 minutes. As control were fish without treatment (C-0) and fish soaked in acetic acid (C-A). All samples stored at room temperature. The activity of chitosan as fish preservative was analyzed through pH and antimicrobial test. The pH test were made in the range of 0, 24, 48 and 72 h. The antimicrobial test was done on the storage period 24 h. The results showed that the greater the concentration of chitosan solution, the shorter the soaking time required to obtain the benefits of chitosan as an antimicrobial agent for fish preservation, especially kenyar fish in the form of darne. The fish that are still suitable for consumption for 24 hours of storage are fish that are soaked in a 2.5% (T4) chitosan solution at either 20, 40, or 60 minutes of soaking time.

Biopreservation of paneer using chitosan

The effect of chitosan on microbial, sensory, chemical, and textural characteristics of paneer was investigated for biopreservation and packaging alternatives. Five different concentrations of chitosan solution viz. 0.2%, 0.4%, 0.6%, 0.8%, 1% and three different temperatures viz. 3oC, 20oC and 37oC were selected for the study along with control. Paneer samples coated with 0.8% concentration of chitosan solution observed to bear the least total viable count when compared with other concentrations. Yeast, mold, and coliform count were found nil in all the samples under study. There was no significant difference in the overall acceptability of the paneer samples coated with chitosan solution of different concentrations when subjected to sensory analysis. The proximate compositional analysis viz. moisture, fat, protein, ash, and acidity of the coated pannier samples are reported. Textural analyses of 0.8% chitosan-coated paneer were carried out for the attributes viz. hardness, springiness, adhesiveness, cohesiveness, gumminess, and chewiness and compared with the market samples of paneer.

Effect of 1-Methylcyclopropene combined with chitosan-coated film on storage quality of passion fruit

Passion fruit is susceptible to pathogens attack and shriveling during storage. This study investigated the synergistic effect of 1-Methylcyclopropene (1-MCP) and chitosan on passion fruit. Passion Fruit treated with a combination of 1 μL/L 1-MCP and four different concentrations of chitosan solution (0, 0.5%, 1%, 1.5%, w/v), then stored at 4 °C. 1-MCP combined 1% (w/v) chitosan-coated film was more effective in improving the storage quality of passion fruit than treatment of 1-MCP combined with other concentrations of chitosan-coated. In addition, 1-MCP combined 1% (w/v) chitosan-coated film decreased the weight loss rate, shrinkage index, and respiratory rate. Furthermore, it inhibited the peroxidase (POD) and ascorbate peroxidase (APX) activity decrease. Therefore, 1-MCP combined with 1% (w/v) chitosan-coated treatment provides a new option for preserving passion fruit.

Application of Chitosan From Waste Gurami Fish Scales (Osphronemus goramy) and Clove Powder (Syzygium aromaticum) As Edible Coating on Chicken Meat

Chicken meat is a nutritious food that can increase immunity but has perishable food properties that are easily damaged so it is necessary to add preservatives, namely chitosan as an edible coating to protect the meat from microbial contamination. Gourami (Osphronemus goramy) scales have the potential to be processed as chitosan. Through 3 stages, namely deproteination, demineralization, and deacetylation. The purpose of this study was to determine the effect of adding chitosan with gourami fish scales and cloves as an edible coating on the quality of raw chicken meat at room temperature for 9 h. This study used a factorial completely randomized design (3×3), with factor A: concentration of chitosan solution (0%, 1%, and 2%) and factor B: concentration of clove solution (0%, 1%, and 2%) and repeated 3 times. The results showed that the control treatment without clove and chitosan after 9 h of storage at room temperature had a significant difference in effect on the treated samples. The best treatment was found in the interaction of 2% chitosan (K2) and 2% cloves (C2) with microbial contamination of 2×10 5 CFU/g so that it still meets the standards of the National Standardization Agency (BSN) namely, chicken meat has a maximum requirement of 1×106 CFU/g, which can maintain the quality of meat, both in terms of pH, water content, and acceptability of organoleptic values which are still favored by panelists.

UJI PELAPISAN CHITOSAN PADA BUAH NAGA ‘SUPER RED’ (Hylocereus costaricensis) UPAYAMEMPERTAHANKAN KESEGARAN BUAH DAN MEMPERPANJANG MASA SIMPAN

Chitosan coating on dragon fruit, until now has not been widely carried out, so research is needed using various concentrations of chitosan solution, in order to obtain optimal results. The aims of this research are to: 1). get the optimal concentration of Chitosan coating solution to maintain fruit freshness and extend shelf life, 2). Knowing the changes in the physical and chemical characteristics of super red dragon fruit with chitosan coating at room temperature storage. The experimental design used one factor RAK, namely the chitosan coating factor. Chitosan coating treatment consisted of 5 levels, namely without Chitosan coating (P0), Chitosan coating 1.0% (P1), Chitosan coating 2.0% (P2), Chitosan coating 3.0% (P3) and Chitosan coating 4.0% (P4). Each treatment was repeated 3 times and obtained 15 experimental units, each experimental unit consisted of 5 pieces (2 pieces were used for non-destructive observations, 3 pieces were used for destructive observations). The results of this study are 1). The chitosan coating treatment was effective in delaying the ripening phase of the fruit at room temperature so that the physical and chemical quality of the fruit was much better until storage of 10 HSP compared to the control, 2) The 2% chitosan coating treatment (P2) was an effective treatment that could maintain the quality of super red dragon fruit up to 10 HSP seen from the visual quality, namely a) changes in skin color dark red and slightly shiny, b) skin texture slightly wrinkled, c) has a fairly fresh condition, d) lowest weight loss (22.34 g), e) smallest decrease in skin hardness (1.09 kgf), f) has better chemical quality such as TPT content 12.73oBrix, TAT 0.64% and vitamin C content 10.27%, 3) Treatment without chitosan (P0) and too high concentrations (3.0% and 4.0% ) is not effective on dragon fruit because it produces poor physical and chemical qualities.

EXTRACTION, CHARACTERIZATION AND APPLICATION OF CHITOSAN DERIVED FROM MAGGOT (BLACK SOLDIER FLY) WASTE AS EDIBLE COATING FOR RED GRAPES (Vitis vinifera)

<p class="Abstrak"><span class="tlid-translation"><span lang="EN-GB">Black Soldier Fly (BSF) farming showed an increasing trend in the past 5 years. The production process generates a leftover, that is the exuviae which are still untapped. BSF exuviae contain chitin and chitosan which can be utilized in various fields, one of which is fruit preservatives. Grapes (<em>Vitis vinifera</em>) is known to have many benefits and has a content of vitamins A, B, C, and E but it has a short shelf life. The purpose of this study was to characterize chitosan from BSF exuviae and choose the best edible coating method to be applied to grapes to prolong the grape’s storage time. Characterization includes physical condition, percent solubility, degree of deacetylation, and yield of the chitosan. Then, edible coating tests were carried out with 2% acetic acid solvent followed by two different methods, namely dyeing method with 5, 10 and, 15 minutes immersion time and spray method with a chitosan solution concentration of 0,5%, 1%, 1,5%, 2 %, and 2,5%. The results showed that chitosan extracted from BSF exuviae produced a physical appearance in the form of white brown powder with 55% solubility and a degree of deacetylation of 91,88%. The chitin yield is 16,2%, followed by the chitosan yield of 4,8%. The best edible coating method which can maintain the physical appearance of grapes and inhibiting fruit decayed was obtained by dipping method at a concentration of 2,5% for 10 minutes. Based on the overall observations, however, the results obtained from the dip and spray method were not significantly different.</span></span></p>

PENGARUH PELAPISAN CHITOSAN TERHADAP DAYA SIMPAN BUAH MANGGA (Mangifera indica L.)

Mango (Mangifera indica L .) is a climacteric fruit, which is able to continue the process of ripening after harvest. The mangoes that have been harvested experience a spike in the respiration rate, which can reduce the shelf life of the fruit. Thus, efforts are needed to reduce the rate of fruit respiration. One method that can be used to reduce the respiration rate of fruit is chitosan coating. The purpose of this study was to determine the effect of the concentration of chitosan solution on the shelf life of mangoes. This research was conducted at the Postharvest Handling Laboratory, Faculty of Agriculture and Business, Satya Wacana Christian University. This study uses two types of mangoes, namely arum manis and kweni mangoes with three treatments, namely control, chitosan concentration of 1% and chitosan concentration of 2%. The results of this study are the coating of fruit with chitosan affects the rate of respiration, moisture content, and weight loss. Chitosan 1% treatment can suppress the respiration rate of sweet arum mango 0.034 CO 2 /g/minute and 0.022 CO 2 /g/minute on kweni mangoes. Chitosan 1% treatment can reduce the weight loss in sweet arum 6.15% and 11.33% in kweni mango. Chitosan 2% treatment can hold the water content in kweni mangoes up to 9.01%.

Preparation of Freeze-Dried Porous Chitosan Microspheres for the Removal of Hexavalent Chromium

Novel porous chitosan microspheres were successfully produced by a freezing–lyophilization drying method in this study and were then used as adsorbents to remove a toxic iron metal, hexavalent chromium (Cr(VI)). The effects of the concentration of the chitosan solution, syringe diameter, and freezing time on the morphologies of porous chitosan microspheres were characterized. The metal ion adsorption for Cr(VI) was also studied. Results showed that freezing chitosan hydrogel beads at a temperature of −20 °C and subsequently lyophilizing the frozen structure allowed to easily obtain the porous chitosan microspheres with rough surfaces and large pores, which were more suitable for adsorption materials to remove metal ions. A chitosan solution concentration of 3% (w/v) and a syringe diameter of 500 μm allowed the porous microspheres to have a good sphericity, thinner pore walls, and small pore sizes. The adsorption capacity of porous chitosan microspheres for Cr(VI) increased with the increase in freezing time. The pH of the initial adsorption solution ranged from 3.0 to 5.0 and was beneficial to the maximum adsorption efficiency for Cr(VI). The porous chitosan microspheres prepared with 3% (w/v) chitosan solution at −20 °C for a freezing time of 72 h had a higher adsorption capacity of 945.2 mg/g for Cr(VI) than the those at 24-h and 48-h freezing times. Kinetic study showed that the adsorption process could be described by a pseudo-second order (PSO) kinetic model. The equilibrium adsorption rate constant and the adsorption amount at equilibrium for the porous chitosan microspheres increased with an increase in the freezing time, and those for the porous microspheres prepared with 3% chitosan solution at −20 °C for a 72-h freezing time were 1.83 × 10−5 g mg−1 min−1 and 1070.5 mg g−1, respectively. The porous chitosan microspheres have good potential to facilitate the separation and recycling of expensive and toxic Cr(VI) from wastewater.