ABSTRACT
Objective: This study aim to obtain the optimum condition of preparation of hydroxypropyl methylcellulose (HPMC) produced from α-cellulose betung bamboo, physicochemical properties of HPMC powder and its characteristics in a gel formulation. Methods: HPMC of betung bamboo (HPMC BB) were optimized by central composite design (CCD) using three variables (sodium hydroxide concentration, dimethyl sulfate concentration, and temperature) and five levels (0,±1, and±α). The suggested optimum condition was subjected to further characterization. HPMC BB was characterized using Fourier transform infrared (FTIR) spectrometry, particle size analyzer (PSA), x-ray diffraction (XRD), scanning electron microscope (SEM) and compared to HPMC 60SH as the reference. Then, HPMC BB was used as a gelling agent in a gel formulation and the gel was evaluated, including appearance and homogeneity, pH, viscosity, and spreadability. Results: Optimum condition of preparation of HPMC BB was using sodium hydroxide 27.68% (w/v) and 1.26 ml dimethyl sulfate (based on 1 g α-cellulose) at 58.11 °C which resulted in molar substitution 0.21 and degree of substitution 2.09. The results showed that HPMC BB was a fine powder with yellowish-white color, odorless and tasteless, pH 7.02, residue on ignition 1.39%, methoxy groups content 28.56%, hydroxypropoxy groups content 7.09%, mean particle size 98.595 μm, loss on drying 3.62%, and moisture content 7.47%. Flow properties of HPMC BB classified in the fair category. The infrared spectrum and diffraction patterns were relatively similar to HPMC 60SH. The gel has a good homogeneity and spreadability and viscosity 142.5 mPa⋅s. pH 6.37. Conclusion: Based on the comparison to reference, HPMC BB showed relatively similar physicochemical and powder properties. However, HPMC BB is not recommended as a gelling agent in gel formulation because it has a low viscosity.
ABSTRACT
Objective: This study aimed to increase the yield of microcrystalline cellulose (MCC) from kapok pericarpium alpha-cellulose produced by enzymatic hydrolysis using purified cellulase from Termites (Macrotermes gilvus) and to compare the characteristics with the reference product. Methods: In this research, MCC was prepared from kapok pericarpium powder through the chemical isolation process of alpha-cellulose, followed by enzymatic hydrolysis with purified cellulase from Macrotermes gilvus. The yield was improved by using purified cellulase in optimized temperature, pH, and hydrolysis time. Identification was carried out by using ZnCl and infrared spectrophotometry, followed by characterization of MCC include particle size analysis (PSA) and diffractogram pattern (X-Ray Diffraction). The results were compared with Avicel PH 101 as the reference product. Results: Purified cellulase from Macrotermes gilvus showed high cellulose activity. Cellulose in the concentration of 11.743 U/ml formed 49 mm clear zone area with cellulolytic index 7.16 that similar to the formed clear zone area of Trichoderma reesei (50 mm), the optimum hydrolysis condition was achieved at 50 °C, pH 6.0, in 2 h, which produced 80% yield of MCC. Produced MCC was analyzed with ZnCl and FTIR spectrum resulting in positive results, similar to reference. The results of the organoleptic test, particle size analysis, and diffractogram pattern (X-Ray Diffraction) showed crystalline characteristics of MCC is similar to the reference (Avicel PH 101). Conclusion: Cellulase Macrotermes gilvus yielded 80% MCC and higher enzymatic activity than Trichoderma reesei. Based on the organoleptic test, particle size analysis, and diffractogram pattern observation, MCC from kapok pericarpium has shown similar characteristics to reference (Avicel pH 101) and might be potential to be further developed.