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Novel Research on Porous Polymers Using High Pressure Technology
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Porous Polymer Science and Applications, 2022
Fernanda Wariss Figueiredo Bezerra, Jhonatas Rodrigues Barbosa, Lucas Cantão Freitas, Marielba de Los Angeles Rodriguez Salazar, Rafael Henrique Holanda Pinto, Giselle Cristine Melo Aires, Raul Nunes de Carvalho Junior, Jorddy Neves da Cruz
Finally, pectin, a biopolymer formed by different esterified residues of galacturonic acid, is found mainly in citrus fruits and some different food residues. Depending on the degree of esterification, pectin is divided into high methoxyl pectin and low methoxyl pectin and still forms high viscosity gels, even at room temperature (Pierce et al. 2020). Pectin can form an intermolecular junction zone through ionic bonds between divalent cations when the pK is equal to or greater than (3–3.5). Porous polymers based on pectin are biodegradable, have a diversified chemical structure and can be modified by various techniques such as oxidation, copolymerization and carboxymethylation, which help to improve structural and mechanical properties (Pierce et al. 2020).
Molecular substrates of ethanol feedstocks
Published in Ruben Michael Ceballos, Bioethanol and Natural Resources, 2017
Pectin comprises approximately <10% of the total biomass in selected lignocellulosic materials (O’Neill and York, 2003). Pectin-rich biomass generated as waste products from industrial processing of fruits and vegetables has low lignin and high pectin concentrations (Table 1.2), ranging from 12% to 35% of dry weight biomass (Edwards and Doran-Peterson, 2012) (Figure 1.2). Pectins are a family of covalently linked galacturonic acid-rich polysaccharides found in plant cell walls (Albersheim et al., 1996). Galacturonic acid comprises at least 65% of pectin and typically features high levels of methyl esterification (Phatak et al., 1988; Food & Agriculture Organization of the United Nations, 2009; Yapo and Koffi, 2014). All pectin polysaccharides contain galacturonic acid linkages at the O-1 and O-4 positions. Pectin polysaccharides are composed of four major subclasses: homogalacturonan (HG), rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II), and xylogalacturonan (XGA) (Yapo, 2011). HG is a simple structured linear homopolymer of α-1,4-linked galacturonic acid residues and comprises about 65% of pectin (Mohnen, 2008; Wang et al., 2012a). Galacturonic acid residues within this backbone can be methyl esterified at the carboxyl groups at the C-6 position (Gee et al., 1959; Mort et al., 1993; Petersen et al., 2008) and/or O-acetylated at the hydroxyl groups at the O-2 or O-3 positions (Perrone et al., 2002). The degree of methylation and acetylation varies significantly between sources (Wang et al., 2012a; Wang et al., 2014a). Other pectin polysaccharides are considerably more complex. RG-I represents approximately 20%–35% of all pectin. It is composed of a backbone of alternating rhamnose and galacturonic acid subunits that can consist of more than 100 repeating subunits (McNeil et al., 1980; Mohnen, 2008). The rhamnose molecules are often substituted with a variety of side chains mainly composed of arabinans, galactans, and arabinogalactans (Tharanathan et al., 1994; Nakamura et al., 2002; ØBro et al., 2004).
Pistachio hull as an alternative pectin source: its extraction and use in oil in water emulsion system
Published in Preparative Biochemistry & Biotechnology, 2023
Sehra Barış, Aysel Elik, Fahrettin Göğüş, Derya Koçak Yanık
Pectin is a complex hetero-polysaccharide and mainly contains α-(1→4) linked D-galacturonic acid (at least 65% galacturonic acid).[2] It is found in the cell membrane of plants, between the cells, or in the middle lamella region.[3] The most widely used pectin extraction method is the conventional acid extraction method in which hot water acidified with a mineral acid is used. Although the acid extraction method is considered economically advantageous, new methods are being explored in the extraction to reduce the harmful effect of mineral acid uses. Microwave-assisted extraction,[4] ultra-sonication,[5] ultrahigh pressure,[6] and super-high frequency electromagnetic field[7] are some of these methods.
Corrosion inhibition of ferrite bainite AISI1040 steel in H2SO4 using biopolymer
Published in Cogent Engineering, 2021
P.R. Prabhu, Deepa Prabhu, Ayush Chaturvedi, Priyank Kishore Dodhia
The inhibitor used in our experiments is commercially available pectin. It is a structural acid heteropolysaccharide that is found in the medium and primary lamellar cell walls of terrestrial plants. The main constituent is galacturonic acid, which is a sweet acid (a derivative of galactose).
Graphene oxide-reinforced pectin/chitosan polyelectrolyte complex scaffolds
Published in Journal of Biomaterials Science, Polymer Edition, 2021
P. R. Sivashankari, K. Krishna Kumar, M. Devendiran, M. Prabaharan
Polyelectrolyte complexes (PECs) are formed due to the electrostatic interactions between a polycation and a polyanion. Preparation of PECs is gaining popularity due to their versatile applications in the field of waste-water treatment, pharmaceutical and food industries, drug delivery, and tissue engineering. PECs produced from natural polymers are non-toxic, biocompatible, and exhibit unique characteristics that cannot be observed in their polymer counterparts [1]. Among the several natural polymers available, chitosan is highly considered for PEC formation as it is the only pseudo-natural cationic polymer. Chitosan is a linear, semi-crystalline polysaccharide consisting of (1→4)-2-acetamido-2-deoxy-β-D-glucan (N-acetyl β-glucosamine) and (1→4)-2-amino-2-deoxy-β-D-glucan (D-glucosamine) residues [2]. It is obtained by the partial deacetylation of chitin that is present in the exoskeleton of crustaceans like shrimps and lobsters. Chitosan is a highly desirable material for biomedical applications due to its non-toxicity, antibacterial activity, biodegradability, biocompatibility, hemostatic and mucoadhesive properties [3, 4]. Chitosan needs to be crosslinked to impart good chemical and physical stability. A variety of crosslinking agents such as glutaraldehyde, genipin, tripolyphosphate have been used for crosslinking chitosan, but many of these crosslinking agents cause toxicity and may affect the biological application of the resulting chitosan-based composite [5]. PEC formation between chitosan and other polyanionic polymers can increase the stability and suitability of the resulting complexes for biomedical applications without the need for any crosslinking agents [6]. A variety of anionic polymers such as alginate [7], hyaluronic acid, pectin [8], carboxymethyl cellulose [9] and polyglutamic acid [10] have been employed for the fabrication of chitosan-based PECs. Among the polyanionic polymers, pectin is considered to form a PEC more effectively with chitosan when compared to other polymers. Pectin is present in the cell walls of higher plants, and it comprises partially esterified galacturonic acid, rhamnose and several sugar residues. It is used extensively in the food industry as a thickening and gelling agent. In the pharmaceutical industry, pectin is employed as a prophylactic agent, colon-specific drug delivery carrier and inhibitory agent against cancer cell metastasis and survival [11]. Due to the hydrophilic nature, gelling behavior in presence of divalent metal ions and anti-inflammatory properties, pectin has been considered for healing burn wounds and chronic diabetic wounds. The highly esterified galacturonic acid residues of pectin were found to favor the anti-inflammatory activity by suppressing the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) enzymes that are mainly responsible for inflammation reaction [5].