Food grade carboxymethyl cellulose preparation from African star apple seed (<i>Chrysophyllum albidum</i>) shells: optimization and characterization

Abstract

α-cellulose isolated from African star apple seed shell (ASASS) was used as the raw material for the production of food-grade carboxymethyl cellulose (CMC). Preparation of CMC from ASASS cellulose was carried out by an etherification process, using sodium hydroxide and monochloroacetic acid (MCA) at various temperature. The cellulose and CMC were characterized by FTIR, XRD and SEM techniques. Degree of substitution (DS) was determined using potentiometric titration. Solubility increased with DS of CMC increased together with varied conditions but decreased at a certain level. The optimum results of varied conditions were 0.8015 DS for 30% NaOH concentrations; 0.6259 DS for 50℃ temperature and 0.9254 DS for the amount of MCA. The FTIR spectra revealed the functional group modification of native cellulose to CMC, with absorptions at-1-1 1409.49 cm and 1640.05 cm indicating ether and carboxyl functional group respectively. The results of XRD analysis showed that crystallinity of isolated cellulose decreased in the CMC and SEM showed the elongated long fibres in cellulose while the fibrils in CMC are short and rough. The obtained product is well suited for pharmaceutical and food additives.

Recent Developments of Carboxymethyl Cellulose

“…In particular, the value of DS can be fine-tuned by the concentration of reagents like isobutanol, ethanol, NaOH, and etherification agent (MCA). For example, depending on the varying concentration of NaOH, V. Pushpamalar (2006) [ 5 ]; P. Rachtanapun et al (2012) [ 9 ]; A. H. Saputra et al (2014) [ 140 ]; M. S. Yeasmin et al (2015) [ 119 ]; and Ibikunle et al (2020) [ 141 ] reported a range of DS of 0.51–0.82 (for sago waste) [ 5 ]; 0.56–0.87 (for durian rind) [ 9 ]; 0.14–1.76 (for water hyacinth) [ 140 ]; 0.1–2.41 (for corn husk) [ 119 ]; and 0.15–0.93 (for African star apple seed shell) [ 141 ], respectively. A higher DS value was determined mostly against 30% NaOH [ 116 , 119 , 141 ] and negligible at 25% and 10% NaOH [ 5 , 140 ].…”

Micro-/Nano-Carboxymethyl Cellulose as a Promising Biopolymer with Prospects in the Agriculture Sector: A Review

“…Cellulose neither melts nor dissolves readily in hot or cold water solvents due to its strong inter- and intramolecular hydrogen bonds to nearby oxygen [ 44 ]. It has other undesirable properties, such as moisture sensitivity and low resistance to microbial attacks [ 44 , 45 , 46 ]. Therefore, this polymer should ideally be converted into more amenable derivatives.…”

Potentials of African Star Apple (<i>Chrysophyllum albidum)</i> Fruit Shell Adsorbent in Recovery of Valuable Hydrocarbons for Spent Engine Oil

“…About 0.2 mg of sample and 2 mg of potassium bromide were mixed and ground finely before the mixture was compressed to pellet. The infrared spectra of these samples were measured in the transmission of a wavelength -1n umber range between 4000 and 400 cm [27] .…”