Synthesis of Methyl Cellulose From Nang Lae Pineapple Leaves and Production of Methyl Cellulose Film

After harvesting Nang Lae pineapple fruits, their leaves remain as agricultural waste. The Nang Lae pineapple leaves contained moisture up to 82.91±0.22% and 32.21±0.67% (w/w) cellulose. Methyl cellulose, a well-known commercial product which is widely used in agriculture, food, and pharmaceutical industries, from Nang Lae pineapple leaves (MCpl) was synthesized with various NaOH concentrations (30%, 40%, and 50%) and their properties i.e., the degree of substitution (DS), color, viscosity, water solubility, and functional groups (FTIR) were determined. The use of 40% NaOH in the methylation of cellulose gave the highest yield (136.31±26.27%) and the highest DS (1.36±0.03). However, this DS value of MCpl was lower than the DS value (1.61±0.02) of commercial MC (MCc). This synthesized MCpl using 40% NaOH was found to have better properties than the MCpl from others such as the higher lightness (L* 75.17±0.28), higher viscosity (20.40±0.25cP), higher water solubility (86.00±2.00%), and showed the similar FTIR patterns as the MCc. Thus, the synthesized MCpl using 40% NaOH was selected to be applied in the film formation. The film produced from MCpl (2% w/v) showed higher tensile strength (58.30±10.78MPa) and water solubility but lower elongation (19.63±8.15%) than MCc film. There was no significant difference between water vapor transmission rate (WVTR) of MCpl and MCc films. Hence, MCpl film can be a good alternative for using as an edible film

Keywords: Nang Lae pineapple leaves, methyl cellulose, synthesis, edible film

*Corresponding author: Tel: 0-605-391-6754 Fax: 0-665-391-6737
E-mail: wirongrong.ton@mfu.ac.th