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PEMBUATAN FILM KOMPOSIT KITOSAN â€“TAPIOKA : PENGARUH KOMPOSISI TERHADAP KARAKTERISTIK FILM Rokhati, Nur Rokhati; Pramudono, Bambang; Widiasa, I. Nyoman
METANA Vol 9, No 01 (2013): Juli 2013
Publisher : Universitas Diponegoro

Abstract Cassava starch can readily be cast into films. However, the cassava starch film is brittle and weak leading to inadequate mechanical properties. Therefore it is necessary blending with other biopolymers that can overcome these drawbacks. In this study, composite film prepared by blending of cassava starch and chitosan solutions with ratio 2:8, 3:7, 4:8, and 5:5. The results show that the mechanical strength of the film increase with increasing the chitosan content. The significant decline in both permeability and degree of swelling with increasing the content of chitosan in the composite film. The hydrophobic acetyl groups of chitosan caused a notable reduction of wettability as well as water permeability. The degree of swelling experiments showed that the films have the highest degree of swelling in water followed by technical ethanol (Â±95%) and pure analysis ethanol (>99.9%). SEM photographs of the surface of film with the ratio 5:5 have more homogeneous than the ratio 2:8. The amino group peak in IR spectrum of chitosan molecule shifted from 1581 to 1587 cmâˆ’1 with the incorporation of starch. These results suggested that these two film-forming components were compatible and an interaction existed between them. Keywords: Chitosanâ€“starch films; composition, characterization

Membrane Technology Application for Fractionation Process to Obtain High Quality Glucosamine Rokhati, Nur; Istirokhatun, Titik; Hamada, Nur ?Aini; Apriyanti, Dwi Titik
Reaktor Volume 20 No.2 June 2020
Publisher : Dept. of Chemical Engineering, Diponegoro University

Glucosamine, monosaccharide from chitosan obtained from the chitin deacetylation process, has been used widely in various fields such as nutrition, pharmacy, and cosmetics. Glucosamine can be obtained from the hydrolysis of chitosan. Enzymatic hydrolysis provides the advantage of mild reaction conditions, environmentally friendly, and high yield. But until now, the separation of glucosamine from the chitosan hydrolysis fraction has been an obstacle. Ultrafiltration membranes offer an efficient filtration process because they do not require additional chemicals. The performance of ultrafiltration membranes was analyzed from the fractionation process of chitosan hydrolysis. The PES membranes in 10, 25, and 50 kDa were used to filter hydrolyzed Low Molecular Weight Chitosan (LMWC) in varied concentrations. The experiment was carried out in crossflow membrane module for flat sheet at room temperature in 1 bar. The permeate flux during filtration decreased rapidly at the initial and gradually over time because of fouling and concentration polarization. The more concentrated hydrolyzed LMWC solution resulted higher percentage of rejection up to almost 20% at the same membrane MWCO while higher MWCO resulted lower rejection percentage for the same hydrolyzed LMWC concentration. The FTIR spectrum of the used membranes of all types had absorption bands of glucosamine which proved that the fractionation process occurred. The time retention in HPLC chromatograms of glucosamine produced were similar with standard glucosamine. Thus, ultrafiltration could be applied for hydrolyzed LMWC fractionation process.Keywords: fractionation; glucosamine; LMWC; MWCO; ultrafiltration

Layer by Layer Composite Membranes of Alginate-Chitosan Crosslinked by Glutaraldehyde in Pervaporation Dehydration of Ethanol Rokhati, Nur; Istirokhatun, Titik; Samsudin, Asep Muhamad
International Journal of Renewable Energy Development Vol 5, No 2 (2016): July 2016
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.5.2.101-106

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.Â Article History: Received April 12nd , 2016; Received in revised form June 25th , 2016; Accepted July 1st , 2016; Available onlineHow to Cite This Article: Rokhati, N., Istirokhatun, T. and Samsudin, A.M. (2016) Layer by Layer Composite Membranes of Alginate-Chitosan Crosslinked by Glutaraldehyde in Pervaporation Dehydration of Ethanol. Int. Journal of Renewable Energy Development, 5(2), 101-106.http://dx.doi.org/10.14710/ijred.5.2.101-106Â

Produksi Glukosamin melalui Hidrolisis Kitosan Menggunakan Irradiasi Microwave Nur Rokhati; Titik Istirokhatun; Reisa Novita Marpaung; Ananda Dwi Utomo
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2017: PROSIDING SNTKK
Publisher : Seminar Nasional Teknik Kimia Kejuangan

Show Abstract | Download Original | Original Source | Check in Google Scholar

Glucosamine (2-amino-2-deoxy-glucose) is an amino-monosaccharide from chitosan, which has many usesin the field of health, especially for the joints, bones, and teeth. Glucosamine can be obtained by the completehydrolysis of chitosan. The influence of microwave irradiation on the chitosan hydrolysis with catalyzed byhydrochloric acid was studied. The hydrolyzed chitosan was characterized by reducing sugar measurement,and FT-IR analysis. The results were compared between hydrolysis using conventional heating andmicrowave irradiation. Microwave irradiation can increase the reaction rate of glucosamine formation.Under the condition of microwave irradiation, the yield of glucosamine is 72.67% after 20 min hydrolysis.While to obtain yield glucosamine 70% required 2 hours for hydrolysis using conventional heating.Chemical structure by FTIR and the reducing sugar content of the glucosamine produced not different withthe glucosamine purchased from Sigma-Aldrich.

Peningkatan Mutu Simpan Buah dengan Coating Film Komposit Tapioka-Kitosan Nur Rokhati
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2015: Prosiding SNTKK 2015
Publisher : Seminar Nasional Teknik Kimia Kejuangan

Show Abstract | Download Original | Original Source | Check in Google Scholar

In the tropics, damage of fruit after harvest is a major problem that must be solved. This damage is usually caused by metabolic activity in progress at the fruit. If the respiration process involving oxygen from the environment is not controlled then it will accelerate maturity and decay of the fruit. Besides that, horticulture very risky contaminated by fungi and microbes. The results of the analysis of Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) showed that the mixing of chitosan and starch solution can produce a homogeneous film due to the interaction between the hydroxyl groups of starch and the amine groups of chitosan. Application of coating films on strawberries for the shelf life of 10 days was found that the lowest weight loss occurs in pure films of the high molecular weight chitosan (± 200 kDa), whereas the composite films of chitosan and starch which produces the lowest weight loss is the medium molecular weight chitosan (± 100 kDa). The low molecular weight chitosan (± 50 kDa) have the best antimicrobial activity. The addition of tapioca can reduce the antimicrobial activity of chitosan films.

Application of Glyoxal Acrylamide Modified Κ-Carrageenan as A Superabsorbent Polymer in Drug Delivery System Aji Prasetyaningrum; Al Farrel A. Raemas; Nur Rokhati; Bakti Jos
Reaktor Volume 20 No.3 September 2020
Publisher : Dept. of Chemical Engineering, Diponegoro University

The hydrogel is superabsorbent polymers (SAP) that are biodegradable and can be obtained from polysaccharides, lipids, and proteins. Polysaccharides include cellulose, starch and their derivatives, seaweed extracts such as carrageenan, alginate, pectin, and chitosan. Carrageenan is the result of the extraction of red seaweed sap with an alkaline solution. The main objective of this study was to simultaneously increase the strength and properties of κ-carrageenan SAP film with the addition of glyoxal and acrylamide as crosslinkers. The addition of acrylamide (variated from 1 to 7 % b/v) into the k-Carrageenan based SAP hydrogel compound and the presence of glyoxal as crosslink agent (variated from 0 to 1,0 % v/v). The physical properties of the SAP films were analyze using swelling degree and tensile strength. The structural and morphological properties of composite films were analyzed using Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). In addition, the effect of pHs on the releasing drug Poly(vinylpyrrolidone)-Iodine was investigated. This research shows that the addition of acrylamide and glyoxal can improve the physical properties of the modified κ-carrageenan film. Characterization using SEM shows that the addition of glyoxal causes the formation of tissue fibers in SAP. FTIR spectra indicated the formation of cross bonds in modified SAP film at 3294.42 cm-1 (carboxylic acid). The treatment under alkaline conditions will increase drug release ability.Keywords: κ-carrageenan; hydrogels; acrylamide; glyoxal; drug delivery

HIDROLISIS ENZIMATIK KITOSAN DENGAN KOMBINASI ENZIM ENDO-GLUCANASE DAN CELLOBIOHYDROLASE Nur Rokhati; Bambang Pramudono; Titik Istirokhatun; Mohammad Sulchan; Dyah Ayu Kresnianingrum; Luthfi Kurnia Dewi
Reaktor Volume 15 No.4 Oktober 2015
Publisher : Dept. of Chemical Engineering, Diponegoro University

Abstract CHITOSAN ENZYMATIC HYDROLYSIS USING A COMBINATION OF ENDO-GLUCANASE AND CELLOBIOHYDROLASE. Chitosan is very promising in various fields including medicine, pharmacology, and the food industry. However, the application of this polysaccharide is limited by its high molecular weight resulting in its low solubility in aqueous media. In this respect, the chitosan with shorter chain length, display a reduced viscosity and are soluble in aqueous media at pH values close to neutrality. The aim of this study is the hydrolysis of chitosan to obtain a low molecular weight chitosan using enzymes endo-glucanase and cellobiohydrolase. The hydrolysis of chitosan was carried out under a temperature of 40° C and pH 5. Chitosan degradation was monitored by the analysis of reducing sugars and viscosity, whereas the chemical characterization of chitosan is done by using test FTIR (infrared spectroscopy). The results showed that enzyme treatment resulted in a substantial loss in viscosity of the chitosan solution shows depolymerization. Depolymerization using endo-glucanase took place very quickly during the initial 15 minutes. The rate of viscosity decrease on chitosan degradation using cellobiohydrolase is lower than using endo-glucanase. When the reaction time was 4 h, the lowest viscosity is showed by cellobiohydrolase, and the highest solubility is showed by combination of endo-glucanase and cellobiohydrolase. Keywords: endo-glucanase; cellobiohydrolase; chitosan; hydrolysis Abstrak Kitosan dapat dimanfaatkan di berbagai bidang seperti kedokteran, farmasi dan industri makanan. Aplikasi kitosan sering dibatasi oleh berat molekul kitosan yang tinggi sehingga viskositasnya tinggi dan kelarutannya rendah. Kitosan dengan rantai polimer pendek, akan mempunyai viskositas rendah, dan mudah larut pada larutan/air dengan pH mendekati netral. Penelitian ini bertujuan untuk menghidrolisis kitosan secara enzimatis menggunakan enzim endo-glucanase dan cellobiohydrolase. Hidrolisis kitosan dilakukan pada suhu 40 °C dan pH 5. Degradasi kitosan dipantau melalui analisa gula reduksi dan viskositas, sedangkan karakterisasi kimia kitosan dilakukan dengan menggunakan uji FTIR (infra red spectroscopy). Hasil penelitian menunjukkan bahwa hidrolisis enzimatis kitosan dapat menyebabkan terjadinya penurunan berat molekul yang ditandai dengan adanya penurunan viscositas larutan kitosan. Pada 15 menit awal hidrolisis terjadi penurunan viskositas yang sangat besar. Laju penurunan viskositas enzim cellobiohydrolase lebih rendah dibanding dengan enzime endo-glucanase. Setelah waktu reaksi 4 jam, viskositas terendah diperoleh pada enzime cellobiohydrolase, sedangkan kelarutan tertinggi diperoleh pada kombinasi enzime endo-glucanase dan cellobiohydrolase. Kata kunci: endo-glucanase; cellobiohydrolase; kitosan; hidrolisis

Membrane Technology Application for Fractionation Process to Obtain High Quality Glucosamine Nur Rokhati; Titik Istirokhatun; Nur ‘Aini Hamada; Dwi Titik Apriyanti
Reaktor Volume 20 No.2 June 2020
Publisher : Dept. of Chemical Engineering, Diponegoro University

Glucosamine, monosaccharide from chitosan obtained from the chitin deacetylation process, has been used widely in various fields such as nutrition, pharmacy, and cosmetics. Glucosamine can be obtained from the hydrolysis of chitosan. Enzymatic hydrolysis provides the advantage of mild reaction conditions, environmentally friendly, and high yield. But until now, the separation of glucosamine from the chitosan hydrolysis fraction has been an obstacle. Ultrafiltration membranes offer an efficient filtration process because they do not require additional chemicals. The performance of ultrafiltration membranes was analyzed from the fractionation process of chitosan hydrolysis. The PES membranes in 10, 25, and 50 kDa were used to filter hydrolyzed Low Molecular Weight Chitosan (LMWC) in varied concentrations. The experiment was carried out in crossflow membrane module for flat sheet at room temperature in 1 bar. The permeate flux during filtration decreased rapidly at the initial and gradually over time because of fouling and concentration polarization. The more concentrated hydrolyzed LMWC solution resulted higher percentage of rejection up to almost 20% at the same membrane MWCO while higher MWCO resulted lower rejection percentage for the same hydrolyzed LMWC concentration. The FTIR spectrum of the used membranes of all types had absorption bands of glucosamine which proved that the fractionation process occurred. The time retention in HPLC chromatograms of glucosamine produced were similar with standard glucosamine. Thus, ultrafiltration could be applied for hydrolyzed LMWC fractionation process.Keywords: fractionation; glucosamine; LMWC; MWCO; ultrafiltration

PEMBUATAN RESIN PHENOL FORMALDEHID TERHADAP APLIKASINYA SEBAGAI VERNIS Nur Rokhati; Aji Prasetyaningrum
Reaktor Volume 12, Nomor 1, Juni 2008
Publisher : Dept. of Chemical Engineering, Diponegoro University

Phenol formaldehid termasuk kelompok resin sintetis yang dihasilkan dari reaksi polimerisasi antara phenol dengan formaldehid. Ada dua jenis resin phenol formaldehid yaitu : novolak yang bersifat termoplast dan resol yang bersifat termoset. Phenol formaldehid dapat diaplikasikan sebagai vernis karena dapat membentuk lapisan film yang kering.Penelitian dilakukan dengan mereaksikan phenol dan formaldehid dengan pH dan perbandingan mol bervariasi. Jenis novolak dibuat pada suasana asam dengan penambahan HCl, suhu 900C, dan waktu reaksi 5 jam, sedangkan jenis resol dibuat pada suasana basa dengan penambahan NaOH, suhu 800C dan waktu reaksi 3 jam. Hasil resin phenol formaldehid diaplikasikan sebagai vernis pada kayu jati. Hasil penelitian menunjukkan bahwa dengan bertambahnya pH dan perbandingan reaktan, waktu kering semakin lama. Kondisi optimum jenis novolak diperoleh pada pH 2,5 dan perbandingan reaktan 1 : 0,8, sedangkan untuk jenis resol dicapai pada pH 10 dan perbandingan mol reaktan 1 : 2. Aplikasi jenis novolak sebagai vernis kayu menghasilkan warna yang lebih cerah (tingkat gloss tinggi) dibanding dengan jenis resol

PENGARUH DERAJAT DEASETILASI KHITOSAN DARI KULIT UDANG TERHADAP APLIKASINYA SEBAGAI PENGAWET MAKANAN Nur Rokhati
Reaktor Volume 10, Nomor 2, Desember 2006
Publisher : Dept. of Chemical Engineering, Diponegoro University

Industri pengolahan udang banyak menimbulkan hasil samping berupa limbah kulit udang yang belum dimanfaatkan secara optimal, yaitu hanya dijadikan tepung dan campuran makanan ternak. Hal itu kurang memiliki nilai ekonomis dibandingkan dengan mengolahnya menjadi khitin dan khitosan. Khitosan banyak digunakan di berbagai industri. Salah satu penerapan khitosan yang penting dan dibutuhkan dewasa ini adalah sebagai pengawet bahan makanan pengganti formalin. Kualitas khitosan sering dinyatakan dengan besarnya nilai derajad deasetilasi. Penelitian ini bertujuan untuk menentukan kondisi operasi optimum proses deasetilasi khitin serta mempelajari pengaruh derajat deasetilasi terhadap khitosan sebagai bahan pengawet makanan. Proses deproteinisasi dengan larutan NaOH (3.5 % w/v) selama 2 jam pada suhu 65 oC dan proses demineralisasi dalam larutan HCl (1N) selama 30 menit pada suhu kamar. Proses deasetilasi dilakukan dengan memanaskan khitin dengan larutan NaOH (20%, 30%, 40%, 50%, 60%, 70%, 80% w/v) pada suhu (50 oC, 60 oC, 70 oC, 80 oC, 90 oC, 100 oC, 110 oC) selama (1, 2, 3, 4, 5, 6, 7 jam). Parameter respon adalah derajat deasetilasi khitosan. Produk khitosan diaplikasikan untuk pengawet tahu dan analisa mikroba dilakukan dengan menggunakan metode TPC untuk mengetahui pengaruh derajat deasetilasi terhadap kemampuannya mengawetkan makanan. Hasil penelitian menunjukkan bahwa kondisi optimum proses deasetilasi khitin menjadi khitosan adalah pada konsentrasi NaOH 50% dan suhu 100oC selama 1 jam yang memberikan derajat deasetilasi sebesar 71,2%.. Total bakteri pada perendaman tahu selama 3 hari dalam larutan asam asetat ditambah chitosan 6,8.104, dalam larutan asam asetat saja 9,9. 105, dan dalam blangko 8,6. 107, sehingga bisa disimpulkan bahwa khitosan dapat menghambat pertumbuhan bakteri. Namun meningkatnya derajad deasetilasi tidak begitu berpengaruh terhadap penurunan jumlah bakteri.

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