The purpose of this research is to study the effect of concentration and temperature on the cellulose and lignin content, and the reducing sugars produced in the enzymatic hydrolysis of coconut coir. In this research, the coconut coir is pretreated using 3%, 7%, and 11% NaOH solution at 60oC, 80oC, and 100oC. The pretreated coir were assayed by measuring the amount of cellulose and lignin and then hydrolysed using Celluclast and Novozyme 188 under various temperature (30oC, 40oC, 50oC) and pH (3, 4, 5). The hydrolysis results were assayed for the reducing sugar content. The results showed that the alkaline delignification was effective to reduce lignin and to increase the cellulose content of the coir. The best delignification condition was observed at 11% NaOH solution and 100oC which removed 14,53% of lignin and increased the cellulose content up to 50,23%. The best condition of the enzymatic hydrolysis was obtained at 50oC and pH 4 which produced 7,57 gr/L reducing sugar. © 2013 BCREC UNDIP. All rights reserve

Biomass waste utilization for biofuel production such as bioethanol, has become more prominent currently. Coconut coir is one of lignocellulosic food wastes, which is abundant in Indonesia. Bioethanol production from such materials consists of more than one step. Pretreatment and enzymatic hydrolysis is crucial steps to produce sugar which can then be fermented into bioethanol. In this research, ground coconut coir was pretreated using dilute sulfuric acid at 121 o C. This pretreatment had increased the cellulose content and decreased the lignin content of coconut coir. The pretreated coconut coir was hydrolyzed using a mix of two commercial cellulase enzymes at pH of 4.8 and temperature of 50 o C. The enzymatic hydrolysis was conducted at several initial coconut coir slurry concentrations (0.1-2 g/100 mL) and reaction times (2-72 hours). The reducing sugar concentration profiles had been produced and can be used to obtain reaction rates. The highest reducing sugar concentration obtained was 1,152.567 mg/L, which was produced at initial slurry concentration of 2 g/100 mL and 72 hours reaction time. In this paper, the reducing sugar concentrations were empirically modeled as a function of reaction time using power equations. Michaelis-Menten kinetic model for enzymatic hydrolysis reaction is adopted. The kinetic parameters of that model for sulfuric acid-pretreated coconut coir enzymatic hydrolysis had been obtained which are V m of 3.587x10 4 mg/L.h, and K M of 130.6 mg/L.

Texturing by instantaneous controlled pressure drop is used to modify texture of banana slices, which was aimed to improve properties of banana flour. Texturing step is inserted between initial and final hot air drying steps. The aim of this research is to investigate the effect of the texturing on the dehydration kinetic, physical properties and nutritional characteristic of banana. Some impacts of the texturing have been identified. The results of this work showed that the texturing increased the effective moisture diffusivity and the water holding capacity, but reduced the oil holding capacity of banana. This work also showed that the banana texturing inhibited the transformation of banana starch to reduction of sugar that might be attributable to enzyme deactivation during the texturing process. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.

Agricultural solid wastes present abundantly on earth as crops harvesting as well as processing are countinuesly run. Banana peels are one of agricultural solid wastes produced anywhere the banana processing presents. The peels present abundantly in tropical countries such as Indonesia. The carbohydrate content of banana peels make it useful for the production of many chemicals, including feed. Meanwhile the large need in feed in farming including fish farming could prevent farmer to obtain substantial profit. This research studied the possibility of banana peel as one of abundant Indonesian agricultural solid waste to be utilized as fish feed which is known requiring certain level of protein content. This was done by fermenting the peels in fixed bed reaction mode using surface aeration and non-aeration. The fermentation was conducted using yeast Saccharomyces cerevisiae Y1536 and Rhizopus Oryzae FNCC 6157. The reaction time was varied for 1, 3, and 5 days. The important parameters studied were protein contents, and amylase activity of the fermented banana peels. Despite aeration indicated more operational cost, it showed significant impact on the fermentation of banana peels. The best condition for fermentation using Saccharomyces cerevisiae Y1536 were 5 day fermentation with surface aeration which result in the increase of protein content up to 4.05%, the decrease of fiber content up to 1.08%, and amylase activity of 9.99 DP. Whilst the fermentation using Rhizopus Oryzae FNCC 6157 obtained its best result at 1 day fermentation with aeration, which are protein content increase up to 4.04% and fiber content decrease up to 0.69%. However, the fermentation using this mold showed its best amylase activity result of 12.75 DP at 5 day surface aerated fermentation.

No abstract

No abstract

Coconut husk is classified as complex lignocellulosic material that contains cellulose, hemicellulose, lignin, and some other extractive compounds. Cellulose from coconut husk can be used as fermentation substrate after enzymatic hydrolysis. In contrary, lignin content from the coconut husk will act as an inhibitor in this hydrolysis process. Therefore, a pretreatment process is needed to enhance the hydrolysis of cellulose. The objective of this research is to investigate the production of the glucose through dilute acid pretreatment and to obtain its optimum operating conditions. In this study, the pretreatment was done using dilute sulfuric acid in an autoclave reactor. The pretreatment condition were varied at 80 C, 100 C, 120 C and 0.9%, 1.2%, 1.5% for temperature and acid concentration respectively. The acid pretreated coconut husk was then hydrolyzed using commercial cellulase (celluclast) and β-glucosidase (Novozyme 188). The hydrolysis time was 72 hours and the operating conditions were varied at several temperature and pH. From the experimental results it can be concluded that the delignification temperature variation has greater influence than the acid concentration. The optimum operating condition was obtained at pH 4 and 50 C which was pretreated at 100 C using 1.5% acid concentration. Copyright © 2012 by BCREC UNDIP. All rights reserved. (Selected Paper from International Conference on Chemical and Material Engineering (ICCME) 2012)

Received: 28th September 2012, Revised: 2nd October 2012, Accepted: 4th October 2012

[How to Cite: R. Agustriyanto, A. Fatmawati, Y. Liasari. (2012). Study of Enzymatic Hydrolysis of Dilute Acid Pretreated Coconut Husk. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2): 137-141. doi:10.9767/bcrec.7.2.4046.137-141]

[How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4046.137-141 ]

| View in <...

No abstract