Palm Kernel De-Oiled Cake: A Potential Source of Cellulose for the Production of Carboxylmethyl Cellulose for Industrial Uses

Abstract

The problem of over dependence on foreign raw materials such as Carboxylmethyl cellulose for Nigerian industries has been a big threat to the country’s economy. In order to curtail the menace, this work aims at the production of Carboxylmethyl cellulose which serves as a thickening agent, emulsifier, stabilizer, extender etc. from palm kernel de-oiled cake. Palm kernel de-oiled cake was converted to Carboxylmethyl cellulose (CMC), a derivative of cellulose by two reaction steps, mercerization and etherification. Some quality control parameters were assayed on the produced CMC. Fourier Transform Infra-red Spectroscopy (FT-IR) was used to characterize the produced Carboxylmethyl cellulose and the commercial grade CMC as control. Paint formed using CMC was assessed in terms of viscosity, pH, and compared with paint formed using commercial CMC. Carboxylmethyl cellulose is a highly specific substrate for the endo-acting cellulase and its catalytic product (glucose) was assayed using a simple reducing sugar assay such as 3,5-dinitrosalycylic assay. The results of the CMC at the first etherification gave a degree of substitution and kinematic viscosity of 0.65 ± 0.02 and 70.46± 1.20, while at second etherification, the values obtained were 1.0 ± 0.01 and 80.0 ± 1.00 against the values obtained from the commercial grade which were given as 1.7 ± 0.05 and 95.0 ± 0.04 respectively. The result of the FT-IR of the CMC (test) and the commercial CMC shows similarities at a wave-length of 600 - 4000 cm−1 with slight differences. The presence of CMC was quantitatively confirmed by the activity of cellulase enzyme on the product which was estimated by colour development using 3, 5-dinitrosalicyclic acid and read at 540 nm. The results of the CMC showed no significant differences with the commercial grade using a one-way test (ANOVA) p > 0.05. The results showed that palm kernel cake can be a better source of cellulose for the production of CMC which would find many applications in food, drug, paint, paper and allied industries.