Effect of pectin extraction method on properties of cellulose nanofibers isolated from sugar beet pulp

Abstract

In this study, the effect of pectin extraction method on the properties of cellulose nanofibers (CNFs) isolated from sugar beet pulp (SBP) was studied. Pectin was extracted by the industrially practiced method by sulfuric acid hydrolysis or by enzymatic hydrolysis using a cellulase/xylanase enzymes mixture. The CNFs were then isolated by high-pressure homogenization and investigated in terms of their chemical composition, crystallinity, size, degree of polymerization, and re-dispersion in water after freeze-drying. The mechanical properties and surface characteristics of CNF films were also studied. The results showed that fibrillation of the de-pectinated SBP was more efficient for the acid hydrolyzed SBP. CNFs from the acid-hydrolyzed SBP had a slightly wider diameter, higher crystallinity, viscosity, and α-cellulose content but a lower degree of polymerization than CNFs from the enzyme-hydrolyzed SBP. Owing to the presence of more residual hemicelluloses in the CNFs from the enzyme-hydrolyzed SBP, the CNFs had higher re-dispersion ability in water. CNF films from enzyme-hydrolyzed SBP displayed slightly better mechanical properties and higher water contact angle than acid-hydrolyzed CNF films. Graphic abstract

Cellulose Nanofibers/Pectin/Pomegranate Extract Nanocomposite as Antibacterial and Antioxidant Films and Coating for Paper

“…SBP pectin is characterized by a high ability to form micro- and nano-emulsion thanks to the presence of high content of acetyl groups at its polysaccharide chains [ 11 ]. In the current work, pectin could form nanoemulsions from the PGE, as shown in the TEM images in Figure 1 .…”

“…Nevertheless, the use of bio-based surfactants are preferred when it comes to food, food packaging, or cosmetic products. For this reason, maltodextrin and whey protein isolate [ 6 , 10 ], sodium carboxymethyl cellulose [ 7 , 11 ], and chitosan [ 9 ] have been used for preparation of PGE emulsions. In this aspect, sugar beet pectin in particular has high emulsifying activity when compared to pectin isolated from other food residues, such as citrus and apple peels, due to its specific chemical composition, the presence of a high degree of acetylation, and low molecular weight [ 11 ].…”

“…For this reason, maltodextrin and whey protein isolate [ 6 , 10 ], sodium carboxymethyl cellulose [ 7 , 11 ], and chitosan [ 9 ] have been used for preparation of PGE emulsions. In this aspect, sugar beet pectin in particular has high emulsifying activity when compared to pectin isolated from other food residues, such as citrus and apple peels, due to its specific chemical composition, the presence of a high degree of acetylation, and low molecular weight [ 11 ]. On the other hand, pectin from other resources, such as citrus and apple peels, have poor emulsifying properties but have other features such as thickening, gelling, and film forming properties thanks to their much higher molecular weight and much lower degree of esterification than that of SBP [ 12 , 13 ].…”

“…In addition to the specific properties of pectin isolated from SBP, CNFs with elementary fibrils (width ~5 nm) could be easily isolated from SBP after pectin extraction due to the unique cell wall structure of sugar beet where most of the tissue is parenchymal, which is characterized by only a very thin primary wall and loosely organized cellulose nano-size microfibrils embedded in a matrix of hemicelluloses and pectin [ 20 ]. Several publications have studied the isolation of CNFs from SBP using different methods and pretreatments [ 11 ].…”

Extraction and Characterization of Pharmaceutical Grade Microcrystalline Cellulose From Raphia Farinifera Inflorescence

“…Data were taken from 10 to either 75 or 90 degrees Celsius, 2θ at intervals of 0.2 seconds at 25 degrees Celsius. Following the "Segal method" 25,26 , the crystallinity index (CrI) was computed by dividing the height ratio between the intensity of the crystalline peak (I 200 -I am ) and the total intensity (I 200 ) after subtracting the background signal. Topas (v4.2, Bruker AXS) was used to perform nonlinear least-squares fitting of the data, with the crystalline component estimated from the cellulose I structure given by the American Chemical Society 27, 28 .…”