Antioxidant and UV-Blocking Properties of a Carboxymethyl Cellulose–Lignin Composite Film Produced from Oil Palm Empty Fruit Bunch

Abstract

Oil palm empty fruit bunch (EFB) pulp with the highest cellulose content of 83.42% was obtained from an optimized process of acid pretreatment (0.5% v/v H 2 SO 4 ), alkaline extraction (15% w/w NaOH), and hydrogen peroxide bleaching (10% w/v H 2 O 2 ), respectively. The EFB cellulose was carboxymethylated, and the obtained carboxymethyl cellulose (CMC) was readily water-soluble (81.32%). The EFB CMC was blended with glycerol and cast into a composite film. Lignin that precipitated from the EFB black liquor was also incorporated into the film at different concentrations, and its effect on the UV-blocking properties of the film was determined. Interestingly, the EFB CMC film without lignin addition completely blocked UV-B transmittance. The incorporation of lignin at all concentrations significantly enhanced the UV-A blocking and other physical properties of the film, including the surface roughness, thickness, and thermal stability, although the tensile strength and water vapor permeability were not significantly affected. Complete UV-A and UV-B blocking were observed when lignin was added at 0.2% (w/v), and the film also exhibited the highest antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals with an half-maximal inhibitory concentration (IC 50 ) value of 3.87 mg mL –1 .

A Comprehensive Review of Food Hydrogels: Principles, Formation Mechanisms, Microstructure, and Its Applications

“…Carboxymethyl cellulose derived from pineapple plants is an effective vehicle for papain immobilization and forms a strong hydrogen bond between the employed materials [77]. Although CMC can be easily extracted from biomass resources [78], bagasse [79] and empty fruit bunch [80] have also been used to produce carboxymethyl cellulose. Every type of biomass resource imparts unique characteristics to CMC, such as exceptional absorption and adsorption, a high swelling ability, and superior optical properties.…”

Xylooligosaccharides produced from sugarcane leaf arabinoxylan using xylanase from Aureobasidium pullulans NRRL 58523 and its prebiotic activity toward Lactobacillus spp.

“…The structure of obtained SLX was analyzed by Fourier Transform Infrared (FTIR) Spectrophotometer (Nicolet 6700, Thermo Nicolet Corp, Madison) in the range of 4000-400 cm −1 using a KBr that was mixed with a sample at a ratio of 10:1 (by weight) comparing with that of commercial beechwood xylan (Megazyme, Ireland) [ 34 ]. For analysis of sugar composition, SLX was completely hydrolyzed with 4 % (v/v) H 2 SO 4 according to Peng et al [ 35 ].…”

Efficient Protection of Silver Nanowire Transparent Electrodes by All-Biorenewable Layer-by-Layer Assembled Thin Films

“…Raw lignin is water insoluble, but it can be converted into water-soluble derivatives with many phenol and hydroxyl groups with alkali treatment . This alkali-treated lignin has been widely explored for incorporation into polymer films to enhance their UV blocking and antioxidant, thermal, and mechanical properties. , Thus, CNFs and AL can be assembled onto arbitrary substrates by a layer-by-layer (LBL) assembly process through hydrogen bonding and electrostatic interactions based on their oppositely charged surfaces from amine and phenol groups, respectively. LBL assembly is compatible with solution and high-controllable processes by alternate deposition of oppositely charged materials onto arbitrary substrates .…”