Effect of Drying Methods on the Powder and Compaction Properties of Microcrystalline Cellulose Derived from Cocos nucifera

Aim: This work aims at investigating the effect of drying methods on the powder and compaction properties of microcrystalline cellulose (MCC) obtained from the matured fruit husk of Cocos nucifera (CN).

Study Design: Experimental design.

Place and Duration of Study: University of Nigeria, Nsukka from March 2014 to September, 2016.

Methods: Dried CN husk chips were treated with sodium hydroxide to obtain α-cellulose which on further treatment with dilute hydrochloric acid gave MCC. One portion was lyophilized at - 45 ± 2°C for 3 h (coded MCCL-Cocos) while a second portion was fluidized dried at 60 ± 1°C for 2 h (coded MCCF-Cocos). The MCCs were characterized using standard methods. Avicel PH 102 was used as comparing standard.

Results: Physicochemical properties of the derived MCC such as degrees of polymerization DP and crystallinity, molecular weight, morphology and micromeritic properties were determined. The compaction properties were assessed using Kawakita and Heckel equation models. The MCCs had crystallinity index ranging from 81.25 to 82.12%, DP of 222. MCCF-Cocos had better flow indices than MCCL-Cocos. The powders exhibited good densification behaviors based on the Kawakita model assessment. Compacts of MCCL-Cocos were significantly (P = 0.01) harder than MCCF-Cocos compacts. Heckel analysis showed plastic behavior. The compaction properties - hardness and tensile strength of the CN MCCs were lower than that of Avicel PH 102.

Conclusion: Fluid bed dried MCC had better flowability while lyophilized MCC had superior densification and compaction properties. Thus drying methods had an effect on the powder and compaction behavior of C. nucifera MCC.