The presence of water hyacinth (Eichhornia crassipes) as an aquatic plant in many lakes or other basins causes many conservation problems. Many efforts have been devoted to overcome these problems such as by utilization of water hyacinth for energy production, for water treatment, etc. In this research, cellulose was isolated from water hyacinth and further used for membrane preparation. Cellulose isolation was performed by extraction followed by acetylation resulting cellulose diacetate. The membranes were prepared by phase separation methods. The resulting membranes were then characterized by measuring water flux and surface chemistry (by FTIR). In addition, the membranes were examined for filtering humic acid solution as a model of surface water. The results show that cellulose can be isolated from water hyacinth and can further be processed into cellulose diacetate with the yield of 5,6 %. The membrane preparation shows that the concentration of polymer and evaporation time influence the performance of the membrane, where the greater concentration of the cellulose polymer and the longer of the evaporation time results in the denser and the smaller membrane pores.

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Abstract. The coastal areas in Indonesia often have a problem of clean water lack, because the water is classified as brackish water. Therefore, this research investigated the fabrication of CA membranes using phase inversion method for brackish water treatment. Investigation was conducted to study the effect of combination dope composition and evaporation time on separation performance and morphology of the memrbane. Membrane was fabricated by dry-wet phase inversion technique with variation of polymer concentration 17, 18 and 20 wt% in the total solid and evaporation time of 5, 10 and 15 seconds, respectively. The asymmetric membranes were characterized by permeability test through rejection and flux measurements using brackish water as feed. The experimental results from SEM images analysis showed that all the membranes have a thin small porous layer and thicker sub-structure of larger porous layer formed asymmetric membrane. Moreover, the greater polymer concentration is resulting smaller pore size and smaller membrane porosity. The longer evaporation time was also resulted in denser membrane active layer. The best membrane performance was observed at the composition of 20 wt% CA polymer, 1 wt % polyethylene glycol with the solvent evaporation time of 15 seconds.

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Less attention has been paid for the effects of surfactant on

Abstract. Food quality is an important factor in food sector. One way to increase the quality of food is by applying edible coating to slow down the degradation of foods quality. Combination of chitosan and green tea extract is one of the types of edible coating which many function as food preservative Green tea extract is chosen because of its high antioxidant contents. The goal of this research is to make a film from the composite of chitosan and green tea extract as a food coating and to observe the effect of chitosan concentration and the addition of green tea extract to the phenolic contents and antioxidant activity of the film. Moreover, this research also aims to apply chitosan film and green tea extract to foods, especially strawberries, and observing the effect of chitosan concentration and the addition of green tea extract to the shrinking of the fruit's weight as well as its antimicrobial activities. Strawberries were coated with five different coating formula including one set as blank (uncoated fruit). The result of this research showed that the increasing of chitosan concentration and the volume of green tea extract addition also increase the antioxidant activity on the film. The phenolic contents on the green tea extract addition will also increase its phenolic contents as well. However, the increasing number of chitosan concentration can reduce the phenolic content on the film. Meanwhile, during the application to strawberries, it is found that 3% chitosan concentration which is combined with the addition of 2.5% green tea extract will minimize the shrinking of the fruit's weight. Also 3% chitosan concentration will give a better antimicrobial activity. In the other side the addition of green tea extract will increase antioxidant activity, the addition of green tea extract also causing a decrease in antimicrobial activity. INTRODUCTIONEdible film is a thin layer of a material that can be consumed and placed between products. Edible films can be either their own sheets or for coatings on food [4,17,21]. This layer serves to protect food products from mechanical damage by reducing the transmission of water vapor, smell, and fat. Edible coatings can be made from materials capable of forming a layer [4,23]. One of the materials that can be used as raw material for edible coating is chitosan Chitosan can be used as a basic material for edible coating because it is one of the non-toxic and edible materials. The advantages compared to other materials are chitosan has a positive amine group that makes it able to form a good layer and its antimicrobial properties [4,17].In edible coatings of chitosan can be added with other additives. One of them is by adding green tea extract. Green tea is known to contain many polyphenolic compounds. Polyphenol compounds are known to function as excellent antioxidants. Therefore, green tea extract will give its own value when added in the manufacture of edible coating. The purpose of this research is (1) Making edible coating of combination of chitosan and green tea ext...

Hydrophilicity of membrane causing only water can pass through membrane. Pervaporation process using organophilic membrane has been offered as alternative for ethanol dehydration. This paper investigate pervaporation based biopolymer composite membrane from alginate-chitosan using layer by layer method prepared by glutaraldehyde as crosslinking agent and polyethersulfone (PES) as supported membrane. Characterization of crosslinked of composite membrane by FTIR helped in identification of sites for interaction between layers of membrane and support layer (PES). The SEM showed a multilayer structure and a distinct interface between the chitosan layer, the sodium alginate layer and the support layer. The coating sequence of membranes had an obvious influence on the pervaporation dehydration performance of membranes. For the dehydration of 95 wt% ethanol-water mixtures, a good performance of PES-chitosan-alginate-chitosan (PES/Chi/Alg/Chi) composite membrane was found in the pervaporation dehydration of ethanol.

The low solubility in common solvent and high viscosity resulting from its high molecular weight (MW) with fiber-like structure prevents a more widespread use of chitosan. This paper presents a performance comparison of nonspecific, commercially available enzymes, α- and β-amylases, for the hydrolysis of chitosan to lower its MW. The results showed that both enzymes demonstrate the ability to be used as catalysts in chitosan hydrolysis with β-amylase having better performance than α-amylase. The chitosan hydrolysis was influenced by not only the enzyme and the chitosan characteristics but also the hydrolysis condition. The optimum pH solution was 4 for α-amylase and 5 for β-amylase. The hydrolysis temperature was found to be optimal at 90 and 50°C for α- and β-amylases, respectively.