scholarly journals Chitin, Chitosan, and Submicron-Sized Chitosan Particles Prepared from Scylla serrata Shells

2020 ◽  
Vol 2 (2) ◽  
pp. 139-149
Keyword(s):  
Molecular Weight ◽  
Sodium Tripolyphosphate ◽  
Average Molecular Weight ◽  
Value Added ◽  
Scylla Serrata ◽  
Mud Crab ◽  
Practical Applications ◽  
Degree Of Acetylation ◽  
Wide Range ◽  
Chitin And Chitosan

Extraction of chitin from mud crab (Scylla serrata) shells, involving demineralization and deproteinization, and deacetylation of the extracted chitin to form chitosan were investigated. The mud crab chitin and chitosan were obtained with a good yield (16.8% and 84.7% based on dried weight basis). The physicochemical properties, functional groups, molecular weight, and degree of acetylation of the chitin and chitosan were characterized. The surface morphology, the orientation arrangement of polysaccharide strands, and crystallinity of the chitin and chitosan prepared from the mud crab shells were investigated. SEM, FTIR, and XRD analyses demonstrated that the chitin consists of micron-sized fibrils, belonging to α from with the crystallinity of 60.1%. The chitosan has a viscosity-average molecular weight of 6.83 kDa with the degree of acetylation being 9.6% and the crystallinity of 73.8%. The chitosan was successfully fabricated into submicron-sized particles using top-down ionotropic gelation, microwave, and microemulsion methods, employing sodium tripolyphosphate, potassium persulfate, and glutaraldehyde as reagents, respectively. Overall, the results indicated that the preparation of chitin, chitosan, and submicron-sized chitosan particles from mud crab shells could open the opportunity for the value-added seafood waste to be utilized in a wide range of practical applications.

scholarly journals Utilization of Food Processing By-products in Extrusion Processing: A Review

2021 ◽  
Vol 4 ◽  
Author(s):  
Debomitra Dey ◽  
Jana K. Richter ◽  
Pichmony Ek ◽  
Bon-Jae Gu ◽  
Girish M. Ganjyal
Keyword(s):  
Functional Properties ◽  
Low Cost ◽  
Value Added ◽  
Raw Material ◽  
Practical Applications ◽  
Extrusion Processing ◽  
High Production Rate ◽  
Wide Range ◽  
Extruded Products ◽  
By Products

The processing of agricultural products into value-added food products yields numerous by-products or waste streams such as pomace (fruit and vegetable processing), hull/bran (grain milling), meal/cake (oil extraction), bagasse (sugar processing), brewer's spent grain (brewing), cottonseed meal (cotton processing), among others. In the past, significant work in exploring the possibility of the utilization of these by-products has been performed. Most by-products are highly nutritious and can be excellent low-cost sources of dietary fiber, proteins, and bioactive compounds such as polyphenols, antioxidants, and vitamins. The amount of energy utilized for the disposal of these materials is far less than the energy required for the purification of these materials for valorization. Thus, in many cases, these materials go to waste or landfill. Studies have been conducted to incorporate the by-products into different foods in order to promote their utilization and tackle their environmental impacts. Extrusion processing can be an excellent avenue for the utilization of these by-products in foods. Extrusion is a widely used thermo-mechanical process due to its versatility, flexibility, high production rate, low cost, and energy efficiency. Extruded products such as direct-expanded products, breakfast cereals, and pasta have been developed by researchers using agricultural by-products. The different by-products have a wide range of characteristics in terms of chemical composition and functional properties, affecting the final products in extrusion processing. For the practical applications of these by-products in extrusion, it is crucial to understand their impacts on the qualities of raw material blends and extruded products. This review summarizes the general differences in the properties of food by-products from different sources (proximate compositions, physicochemical properties, and functional properties) and how these properties and the extrusion processing conditions influence the product characteristics. The discussion of the by-product properties and their impacts on the extrudates and their nutritional profile can be useful for food manufacturers and researchers to expand their applications. The gaps in the literature have been highlighted for further research and better utilization of by-products with extrusion processing.

scholarly journals Extraction, Characterization and Application of Cashew Nut Shell Liquid from Cashew Nut Shells

2019 ◽  
pp. 1-10 ◽  
Author(s):  
Sampson Kofi Kyei ◽  
Onyewuchi Akaranta ◽  
Godfred Darko ◽  
Uche J. Chukwu
Keyword(s):  
Chemical Characterization ◽  
Value Added ◽  
Industrial Applications ◽  
Physical Analysis ◽  
Cashew Nut Shell Liquid ◽  
Liquid Resin ◽  
Practical Applications ◽  
Cashew Nut ◽  
Wide Range ◽  
Cashew Nut Shell

In this study, cashew nut shell liquid has been extracted from cashew nut shells using an accelerated solvent extraction technique and was employed as a precursor for the synthesis of cashew nut shell liquid resin. The extract was a dark brown viscous liquid with an average yield of 30.61±0.200%. Results of the physical analysis showed a moisture content of 4.45±0.020% and a density of 0.95±0.300 gcm-3. The percentage brix and refractive index were 76.20±0.001 and 1.47 ±0.010 respectively. Chemical characterization showed a pH of 5.65±0.003; acid value of 8.25± 0.200 mg KOH/g; ash content of 1.80±0.6%; free fatty acid of 4.12±0.400 mg KOH/g; ester value of 247.01±0.100 mg KOH/g and a saponification value of 255.26±0.800 mg KOH/g. The FTIR spectra revealed that cashew nut shell liquid is polymeric. These findings confirm that higher phenolic compounds which can be used as potential precursors in industrial applications could be obtained from agro wastes. Practical Applications: Cashew nut shell liquid, an extract from cashew nut shell, an agro waste has a wide range of functional products. A practical application is synthesis of a high viscous, flexible cashew nut shell liquid resin with physical properties that are consistent with literature and could also be further used in other industrial applications. Further processing of cashew nut shell for the development of value added products like resin can be a better option.

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

2021 ◽  
Vol 934 (1) ◽  
pp. 012092
Author(s):  
R Karnila ◽  
S Loekman ◽  
S Humairah
Keyword(s):  
Moisture Content ◽  
Ash Content ◽  
Scylla Serrata ◽  
Crab Shell ◽  
Mud Crab ◽  
Degree Of Deacetylation ◽  
Randomized Design ◽  
Chitin And Chitosan ◽  
Two Stages

Abstract 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%.

scholarly journals Kefiran biopolymer: Evaluation of its physicochemical and biological properties

2018 ◽  
Vol 33 (5) ◽  
pp. 461-478 ◽  
Author(s):  
Hajer Radhouani ◽  
Cristiana Gonçalves ◽  
Fátima R Maia ◽  
Joaquim M Oliveira ◽  
Rui L Reis
Keyword(s):  
Molecular Weight ◽  
Photoelectron Spectroscopy ◽  
Average Molecular Weight ◽  
Structural Features ◽  
Biological Properties ◽  
Health Claims ◽  
Extrusion Force ◽  
Wide Range ◽  
Physicochemical And Biological Properties ◽  
Kefir Grains

Kefiran, an exopolysaccharide produced by lactic acid bacteria, has received a great interest due to a variety of health claims. In this study, we aim to investigate the physicochemical and biological properties of Kefiran polysaccharide extracted from Portuguese kefir grains. The kefir growth rate was about 56% (w/w) at room temperature and the kefir pH after 24 h was about 4.6. The obtained yield of Kefiran polysaccharide extracted from the kefir grains was about 4.26% (w/w). The Kefiran structural features were showed in the 1H nuclear magnetic resonance spectrum. The bands observed in the infrared spectrum confirmed that the Kefiran had a β-configuration; and the X-ray photoelectron spectroscopy analysis confirmed the structure and composition of Kefiran and revealed a C/O atomic ratio of 1.46. Moreover, Kefiran showed an average molecular weight (Mw) of 534 kDa and a number-average molecular weight (Mn) of 357 kDa. Regarding the rheological data obtained, Kefiran showed an interesting adhesive performance accompanied by a pseudoplastic behavior, and the extrusion force of Kefiran was 1 N. Furthermore, Kefiran exhibited a higher resistance to hyaluronidase degradation than hyaluronic acid. Finally, Kefiran showed a lack of cytotoxic response through its ability to support metabolic activity and proliferation of L929 cells, and had no effect on these cells’ morphology. Our research suggested that Kefiran polymer has attractive and interesting properties for a wide range of biomedical applications, such as tissue engineering and regenerative medicine.

Synthesis and Properties of a Novel Thermostable Polymer: Fluorinated Polycarbodiimide

1997 ◽  
Vol 9 (4) ◽  
pp. 385-395 ◽  
Author(s):  
Amane Mochizukiy ◽  
Michie Sakamotoy ◽  
Masahiro Yoshiokay ◽  
Yuji Hottay ◽  
Takahiro Fukuokay ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Decomposition ◽  
Dielectric Constant ◽  
Thermal Properties ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Thermostable Polymer ◽  
Lower Dielectric Constant ◽  
Wide Range ◽  
Solution Polycondensation

A new fluorinated linear polycarbodiimide (F-PCD) was synthesized by solution polycondensation of a new fluorinated diisocyanate monomer, 4″, 4″′-(hexafluoroisopropylidene) bis(4-phenoxyphenyl isocyanate) (HPI) in the presence of 3-methyl-1-phenyl-2-phospholene-1-oxide (PMO). HPI was prepared from 4″, 4″′-(hexafluoroisopropylidene)bis(4-phenoxyaniline) (HPA) by three steps. The reaction of HPA with phenyl chloroformate gave the corresponding carbamate, which upon reaction with trimethylsilylchloride (TMS-Cl)-triethylamine (TEA), followed by thermal decomposition, provided HPI. The polymer having a number average molecular weight up to 8400 was obtained in quantitative yield. Thermal properties were investigated and we found that the polymer has a higher glass transition temperature ( Tg)upto 230 °C, and a lower dielectric constant at 2.98 at 1 MHz than the conventional polycarbodiimides (PCDs). The linear F-PCD was soluble in a wide range of common organic solvents such as toluene and dichloromethane.

scholarly journals A Systematic Study on the Degradation Products Generated from Artificially Aged Microplastics

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1997
Author(s):  
Greta Biale ◽  
Jacopo La Nasa ◽  
Marco Mattonai ◽  
Andrea Corti ◽  
Virginia Vinciguerra ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Weight ◽  
Degradation Products ◽  
Average Molecular Weight ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Molecular Weight ◽  
Photo Degradation ◽  
Degradation Processes ◽  
Wide Range

Most of the analytical studies focused on microplastics (MPs) are based on the detection and identification of the polymers constituting the particles. On the other hand, plastic debris in the environment undergoes chemical and physical degradation processes leading not only to mechanical but also to molecular fragmentation quickly resulting in the formation of leachable, soluble and/or volatile degradation products that are released in the environment. We performed the analysis of reference MPs–polymer micropowders obtained by grinding a set of five polymer types down to final size in the 857–509 μm range, namely high- and low-density polyethylene, polystyrene (PS), polypropylene (PP), and polyethylene terephthalate (PET). The reference MPs were artificially aged in a solar-box to investigate their degradation processes by characterizing the aged (photo-oxidized) MPs and their low molecular weight and/or highly oxidized fraction. For this purpose, the artificially aged MPs were subjected to extraction in polar organic solvents, targeting selective recovery of the low molecular weight fractions generated during the artificial aging. Analysis of the extractable fractions and of the residues was carried out by a multi-technique approach combining evolved gas analysis–mass spectrometry (EGA–MS), pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS), and size exclusion chromatography (SEC). The results provided information on the degradation products formed during accelerated aging. Up to 18 wt% of extractable, low molecular weight fraction was recovered from the photo-aged MPs, depending on the polymer type. The photo-degradation products of polyolefins (PE and PP) included a wide range of long chain alcohols, aldehydes, ketones, carboxylic acids, and hydroxy acids, as detected in the soluble fractions of aged samples. SEC analyses also showed a marked decrease in the average molecular weight of PP polymer chains, whereas cross-linking was observed in the case of PS. The most abundant low molecular weight photo-degradation products of PS were benzoic acid and 1,4-benzenedicarboxylic acid, while PET had the highest stability towards aging, as indicated by the modest generation of low molecular weight species.

Can Ultrafiltration Occur with a Hypo-Osmolar Solution in Peritoneal Dialysis?: The Role for ‘Colloid’ Osmosis

1993 ◽  
Vol 85 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Chandra D. Mistry ◽  
Ram Gokal
Keyword(s):  
Molecular Weight ◽  
Peritoneal Dialysis ◽  
Polymer Solution ◽  
Corn Starch ◽  
Average Molecular Weight ◽  
Dialysis Solution ◽  
Wide Range ◽  
Glucose Polymer ◽  
Metabolic Correction

1. In peritoneal dialysis the removal of excess body water (ultrafiltration) is traditionally achieved by means of dialysis solution made hypertonic to plasma by the addition of an osmotic agent. In vitro, the osmotic flow may be directed against the osmolality gradient by using a hypo-osmolar solution, but this phenomenon has not previously been applied to clinical peritoneal dialysis. 2. The ultrafiltration performances of hypo-osmolar dialysis solutions containing a high-molecular-weight glucose polymer (weight average molecular weight 22 000), isolated by fractionation of hydrolysed corn starch, were compared with those of hypertonic glucose solutions over a 12 h exchange in 11 patients well established on continuous ambulatory peritoneal dialysis. 3. Five per cent (272 +1.1 mosmol/kg) and 7.5% (277 + 2.0 mosmol/kg) glucose polymer solutions produced net ultrafiltration of 243 +53 and 526 +59 ml that were significantly greater than the ultrafiltration of −48 +96 and 223 +84 ml associated with 1.36% (339 +1.9 mosmol/kg) and 2.27% (393 +3.2 mosmol/kg) glucose solutions, respectively. The net ultrafiltration with 10% glucose polymer (284 +2.0 mosmol/kg) and 3.86% glucose (482 + 1.6 mosmol/kg) solutions were similar (699 +48 versus 708 +82 ml). 4. The transperitoneal absorption of glucose polymer was substantially lower than that of glucose solutions as was the potential calorie load per millilitre of ultrafiltrate. 5. The addition of 0.35% glucose (molecular weight 180) to 7.5% glucose polymer solution raised the dialysate osmolality to an iso-osmolar level (299 +0.8 mosmol/kg) and produced ultrafiltration which was 29% greater than with 7.5% glucose polymer solution alone. 6. The demonstration of ultrafiltration with hypo-osmolar dialysate represents an important advance towards the formulation of a physiological iso-osmolar dialysis solution, which may have long-term benefits over the conventional hypertonic solutions. The iso-osmolar combination of ‘colloid’ and ‘crystalloid’ osmotic agents looks promising with a potential for a wide range of ultrafiltration capabilities as well as metabolic correction.

Extraction, Characterization and Physico Chemical Properties of Chitin and Chitosan from Mud Crab Shell (Scylla Serrata)

2011 ◽  
Vol 3 (8) ◽  
pp. 44-46 ◽  
Author(s):  
A. Kiruba A. Kiruba ◽  
◽  
V. Uthayakumar V. Uthayakumar ◽  
S. Munirasu S. Munirasu ◽  
V. Ramasubramanian V. Ramasubramanian
Keyword(s):  
Chemical Properties ◽  
Scylla Serrata ◽  
Crab Shell ◽  
Mud Crab ◽  
Physico Chemical ◽  
Chitin And Chitosan

A Comprehensive Kinetics Library for Simulating the Combustion of Automotive Fuels

2018 ◽  
Author(s):  
Chitralkumar V. Naik ◽  
Karthik V. Puduppakkam ◽  
Ellen Meeks
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Carbon Number ◽  
Diagnostic Methods ◽  
Specific Rate ◽  
Number Range ◽  
Wide Range ◽  
Reduction Methods ◽  
Ignition Quality ◽  
Fuel Components

With advanced engines pushing the limits of fuel efficiency, rapid development and improvement of engines increasingly rely on insights from simulations. Reliable simulations require fuel models that consist of a fuel surrogate and its kinetic mechanism. As complexity and sources of fuels vary, a good surrogate needs to be tailored for the specific test fuel. A simple surrogate, typically consisting of 1 to 3 components, can match a single property of the real fuel, such as ignition quality or average molecular weight. More complex surrogates with 4 to 7 components can capture many properties simultaneously. While simple surrogates are good for estimating ignition in engines they require some compensation for the mismatch of the fuels’s physical properties. Complex surrogates can be used to directly represent real fuels in both laboratory experiments and simulations. We have developed a surrogate blending methodology to identify surrogates with a desired degree of complexity. This involves methods that estimate properties for fuel blends, including ignition quality, sooting propensity, distillation curve, as well as other physical and chemical properties that are important to combustion behavior in simulations. We have assembled and developed a rich library of over 60 fuel components from which we can formulate surrogates to represent most gasoline, diesel, gaseous fuels, renewable fuels, and several additives. The components cover a carbon number range from 1 to 20, and chemical classes including linear and branched alkanes, olefins, aromatics with one and two rings, alcohols, esters, and ethers. As part of the library, we have assembled self-consistent and detailed reaction mechanisms for all the components. The mechanisms also include comprehensive NOx creation and destruction pathways, molecular weight growth kinetics leading to the formation of polycyclic aromatic hydrocarbons (PAH), and a detailed soot-surface mechanism. The mechanisms have been validated extensively using over 500 published sets of experimental kinetics data from a wide range of facilities and diagnostic methods. Over the past decade, the validation suite has been used to improve the kinetics database such that good predictions and agreement to data are achieved for the fuel components and fuel-component blends, within experimental uncertainties. This effectively eliminates the need to tune specific rate parameters when employing the kinetics mechanisms in combustion simulations. For engine simulations, the master mechanisms have been reduced using a combination of available reduction methods while strictly controlling the error tolerances for targeted predictions. These include several directed relation graph (DRG) based methods and sensitivity analysis. Iteratively using these reduction methods has resulted in small mechanisms for efficiently incorporating the validated kinetics into computational fluid dynamics (CFD) applications. The surrogate formulation methodology, the comprehensive fuel library, and mechanism reduction strategies suggested in this work allow the use of CFD to explore design concepts and fuel effects in engines with reliable predictions.

Sign in / Sign up

Export Citation Format

Share Document