Screening factors affecting chitosan extraction from mud crab (Scylla sp.) shell using microwave irradiation for the Response Surface Approach

Extracting chitosan from crab shell using conventional method requires processing in strong acid and alkali conditions under high temperature with long reaction time. Microwave-based extraction proposes shorter processing time, and hence energy and cost efficient. This study intended to screen factors affecting the extraction of chitosan from mud crab shell using microwave irradiation. The factors would be used in Response Surface Methodology (RSM) approach to obtain the optimum conditions for chitosan extraction. Microwave irradiation was employed in all of the three steps of chitosan extraction, the demineralization, deproteination, and deacetylation processes. A fractional factorial design was used to screen eight independent factors to determine the most significant ones to be optimized to determine the maximum value of four responses, which were yield, mineral removal, degree of deacetylation and moisture content. The results show that all of the main independent variables were significant in affecting minimal one of the 4 responses (P < 0.05). Mud crab chitosan had the degree of deacetylation of 87.72 – 95.13 %. Results of the screening analysis concluded, the main independent factors that are going to be applied in the optimization study are NaOH concentration, microwave oven power, and reaction time in deacetylation process.

Comparison of Chitosan Characterization from Mussel Shell Waste Using Varying Concentration of Solvents

Massive amounts of mussel shell waste are generated and wasted from the aquaculture processing sectors, resulting in environmental pollution. This material contains chitosan as a valuable compound characterized as a non-toxic structural component with several food processing applications or medicinal applications. In this research, mussel shells were processed using different solvents concentrations in several stages: demineralization, deproteination, decolourization, and deacetylation. Our result showed that the C2 samples gained a high degree of deacetylation (31.8±0.21%) with low moisture and ash content and medium weight of yield. Further research is recommended to purify chitosan using various instrumentation and assess its bioactivity.

Comparison of the Physicochemical Properties of Chitin Extracted from Cicada orni Sloughs Harvested in Three Different Years and Characterization of the Resulting Chitosan

Chitin and its derivative chitosan are among the most used polysaccharides for biomedical and pharmaceutical applications. Most of the commercially available chitin is obtained from seafood wastes. However, the interest in alternative renewable sources of chitin and chitosan, such as insects, is growing. When new sources are identified, their stability over time has to be evaluated to allow for their commercialization. The aim of this study is to compare the physicochemical properties of chitin extracted from Cicada orni sloughs harvested in three different years (2017, 2019 and 2020) in order to assess the stability of the source and the repeatability of the extraction process. Chitin and its derivative chitosan were characterized by simple techniques such as Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Results suggest that the physicochemical properties of the extracted chitin varied from year to year, and that these differences are not due to the extraction process, but rather to intrinsic differences within the source. We showed that these differences could already be detected by analyzing the raw material (i.e., cicada sloughs) using the above-mentioned simple methods. The chitosan obtained from deacetylation of chitin had a low degree of deacetylation (66.2±1.6%). This low degree of deacetylation can be attributed to the deacetylation process, which is probably not appropriate for this source of chitin.

The Use of Different Deacetylation Temperature Toward Quality of Chitosan Mud Crab Shell (Scylla serrata)

This research aims to determine the chemical composition (proximate) of chitosan and chitin, The best deacetylation temperature for obtaining chitosan, and the yield of chitosan and chitin from mud crab. This research was conducted in two stages, that is: 1) Preparation of mud crab flour and 2) Extraction and analysis of chitin and chitosan. The experimental design used for chitosan isolation was Completely Randomized Design (CRD). The process of deacetylation chitin becomes chitosan by using 50% NaOH with varying heating temperatures (120, 130, and 140°C). Parameters observed were yield, moisture content, ash content, and degrees of deacetylation. The result showed that the best chitosan was obtained by chitin deacetylation process into chitosan using a temperature of 130°C (KO2). Characteristics quality of the chitosan mud crab shell produced are KO1: yield 61.00%, moisture content 6.47%, ash content 17.18% (db), and degree of deacetylation 49.63%. KO2: yield 59.94%, moisture content 6.48%, ash content 14.85% (db) with degree of deacetylation 51.13%. KO3: yield 53,97, moisture content 6.54%, ash content 14.66% (db) and degree of deacetylation 52.63%. Characteristic quality of chitin included yield was 27.81%, moisture content 7.29%, ash 44.05%, and degree of deacetylation 33.09%.

Influence of Deacetylation Process in Chitosan Extract From Shrimp Shell Waste

The increasing production of shrimp commodities in Bangka Belitung Island can cause shrimp shell waste and polluting the environment. Shrimp shell waste can further proceed into chitosan which has a wide range of functions in various fields. This current study aims to find out the influence of the deacetylation process in chitosan extracts from shrimp shell waste. The method of chitosan extraction by varying repetition of deacetylation process. The characterization of chitosan extracts by FTIR analysis to determine functional group and degree of deacetylation (DD). Based on FTIR spectra, repetition in the deacetylation process in chitosan extraction still produces chitosan extracts that do not fully transform into chitosan. However, it able to increase DD with the highest DD of chitosan extract constitutes 86,78% and can be used in the further application.

Effect of Ultrasonic Assisted on The Degree of Deacetylation of Chitosan Extracted from Portunus Pelagicus

The technology for extracting chitin from shell and other materials needs to be continuously improved, including its conversion to chitosan. Chitosan is a biocompatible polymer, biodegradable, non-toxic, water-soluble at pH below 6.5, and it has protonated amino groups. The benefits of chitosan in industry, food and medicine make it necessary to fully study an efficient chitosan synthesis method and the results can be applied on an industrial scale. This study examined the effect of ultrasonic-assisted in increasing the degree of deacetylation of chitosan produced from Portunus pelagicus shell waste. The production process of chitosan goes through the stages of deproteination, demineralization and deacetylation. All these steps are ultrasound assisted processes with a frequency of 40 kHz through a digital ultrasonic cleaner. Ultrasonic-assisted chitin and chitosan were examined using FTIR spectrometry. The results showed that the ultrasonic method was able to increase the deacetylation degree of chitin with a value of 68.45±0.11% compared to 62.52±0.08% without ultrasonic. Application of ultrasonic assisted deacetylation gave a deacetylation degree of 85.35 ± 0.20%, higher than without ultrasonic 80.24 ± 0.19%. Physically, ultrasonic-assisted chitosan is smoother and brighter in color. The ultrasonic-assisted chitosan manufacturing method could increase the deacetylation degree and produce high grade chitosan.

Determination of indicators allowing to evaluating the hemostatic activity of chitosan without a biological experiment

The biopolymer chitosan is widely used for the development of local hemostatic agents. However, the physicochemical parameters of chitosan that determine its hemostatic properties have not yet been determined. Standard quality control of chitosan-containing raw materials and medical products on its basis do not allow us to make a conclusion about the effectiveness of their use for stopping bleeding. The most reliable method for assessing hemostatic activity remains in vivo experiment on large animals. The aim of this study was to determine additional physicochemical parameters of chitosan, which would make it possible to predict its hemostatic activity without conducting a biological experiment. In this work, using the methods of nuclear magnetic resonance spectroscopy, spectrophotometry and viscometry, it has been shown that the ability to initiate hemostasis is depending of the molecular weight and degree of deacetylation of chitosan, but not enough linearly. The hemostatic properties in vitro increases in a series of samples with a relatively constant molecular weight with an increase in the degree of deacetylation. As well as in a series with the same degree of deacetylation with an increase in molecular weight. However, at molecular weight values more than 300 kDa, the viscosity of the polymer causes the opposite effect: with an increase in the degree of deacetylation, the hemostatic activity decreases. The best ability to initiate hemostasis have chitosan samples with a degree of deacetylation of 90.0%–97.4% and molecular weight 145.7–284.7 kDa, in which at pH of solution close to physiological, a significant part of the molecules transitioned from conformation state rigid rod to state globule. It was accompanied by an abrupt change in light transmission of the solution. It was concluded, that it is possible to study conformational states by spectrophotometry to assess the hemostatic activity of chitosan samples without performing biological experiment.

Synthesis of New Chitosan from an Endemic Chilean Crayfish Exoskeleton (Parastacus Pugnax): Physicochemical and Biological Properties

Chitin is one of the most abundant natural polysaccharides in the world and it is mainly used to produce chitosan by a deacetylation process. In the present study, the extraction of chitin and chitosan from the Parastacus pugnax (P. pugnax) crayfish exoskeleton was studied for the first time. Thus, the P. pugnax crayfish exoskeleton was converted to chitosan following the steps of depigmentation, deproteinization, and deacetylation. The produced chitosan (Chitosan-CGNA) was characterized in terms of the protein content, solubility, degree of deacetylation, viscosity, molecular weight, FTIR, SEM, XRD, antimicrobial, and antioxidant activity. The results showed that the obtained chitosan had a high degree of deacetylation (91.55%) and a medium molecular weight (589.43 kDa). The antibacterial activity of the chitosan was tested against bacterial strains relevant for the food industry and the lowest minimum inhibitory concentration (MIC) values were evidenced with Salmonella tiphymurium (S. typhimurium), Staphylococcus aureus (S. aureus), Enterococcus faecalis (E. faecalis) and Listeria. Monocytogenes (L. monocytogenes). Moreover, the Chitosan-CGNA showed an effect on DPPH radical scavenging activity, and its antioxidant activity was dependent on concentration and deacetylation degree. These results suggest that P. pugnax exoskeleton could be an excellent natural source for the production of chitosan with potential applications in the health system, and to prevent infections associated with pathogens strains.

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>