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Abstrak :
Telah dilakukan sintesis dan karakterisasi polimerisasi oksidasi kimia dari monomer pirol menggunakan oksidan amonium persulfat (APS) dalam media pelarut air, melalui teknik polimerisasi emulsi metode batch selama 4 jam dengan kecepatan agitasi 900 rpm dalam temperatur ruang. Surfaktan yang digunakan diantaranya, surfaktan anionik: Sodium dedocyl sulfate (SDS) dan surfaktan nonionik: Nonylphenol Ethoxylate (NP.EO) dengan 10 mol EO. Senyawa PPy dalam penelitian ini berbentuk padatan (serbuk) berwarna hitam. Terbentuknya PPy dapat diindentifikasi berdasarkan hasil spektra FTIR terlihat munculnya serapan puncak polimer konduktif PPy dengan intensitas yang kuat pada bilangan gelombang 3001 cm-1, 1503 cm-1, 1428 cm-1, 1175 cm-1 dan 1087 cm-1. Berdasarkan profil perubahan temperatur dan perubahan warna selama proses polimerisasi terlihat polimerisasi emulsi relatif lebih lama kecepatan reaksinya dibandingkan dengan polimerisasi sedimentasi. Nilai pH sistem reaksi polimerisasi dengan surfaktan lebih tinggi (penambahan larutan SDS pH sistem 3.3) dibandingkan polimerisasi tanpa surfakan (1.8). Nilai konduktifitas (σ) PPy dengan surfaktan lebih tinggi (mencapai 186 kali) dibandingkan tanpa surfaktan. Polimerisasi emulsi menggunakan surfaktan anionik, SDS sangat efektif meningkatkan nilai konduktivitas PPy. ...... A conductive Polypyrrole (PPy) has been successfully synthesized and characterized. The PPy was prepared through oxidative chemical polymerization using ammonium persulfate (APS) as an oxidizing agent in aqueous media. Anionic and non-ionic emulsifiers, sodium dodecyl sulfate (SDS), nonylphenol (NP) ethoxylate (EO) with 10 mole EO were respectively used during polymerization to increase the electrical conductivity. In this research is produced PPy which is formed as black powder. The FTIR spectrum of PPy indicates a change in the absorbance peaks of pyrrole monomer, emergence of strong absorbtion peaks specially at 3001 cm-1, 1503 cm-1, 1428 cm-1, 1175 cm-1 and 1087 cm-1 which is indicating the conductive polymer polypyrrole is formed. Based on color changing and temperature changing during the polimerization process, the reaction rate of emulsion polymerization is shown relatively slower than sedimentation polymerization. The pH value of SDS added solution was 3.3 higher than that of SDS free solution (1.8). The final characteristic of PPy was carry out by measuring the electrical conductivity (σ) value. It is concluded that the presence of surfactant in a polymerization reaction increased the electrical conductivity of PPy (reached 186 times higher) compared with that obtained of emulsifier free solution. Anionic surfactant, SDS is more effective to enhance the electrical conductivity value of PPy.

Abstrak :
Pada penelitian ini dilakukan sintesis ester asam lemak hasil hidrolisis minyak jarak dan ester asam risinoleat secara kimiawi dengan menggunakan variasi alkohol yaitu metanol, etanol, 2-propanol, dan 1-butanol serta katalis ZnCl2. Perbandingan mol antara asam lemak dengan alkohol yang digunakan dalam reaksi esterifikasi adalah 1:2. Selain itu reaksi esterifikasi dilakukan variasi waktu pada 4, 6, 8, 10 dan 12 jam. Hidrolisis dari minyak jarak menghasilkan 87% kadar asam lemak. Waktu optimal untuk reaksi esterifikasi adalah 10 jam. Persen konversi paling tinggi diperoleh pada produk metil ester asam risinoleat yaitu sebesar 68%. Hasil karakterisasi menggunakan FTIR menunjukkan adanya serapan gugus C=O ester pada rentang 1750-1735 cm-1 dan C-O ester pada 1210-1163 cm-1. Hasil uji emulsifier produk esterifikasi menunjukkan bahwa setelah 24 jam emulsi yang terbentuk masih cukup stabil, dengan tipe emulsi air dalam minyak (w/o). Kemampuan sebagai emulsifier paling baik ditunjukkan oleh metil ester asam lemak hasil hidrolisis minyak jarak, Hasil uji aktivitas antimikroba terhadap bakteri Propionibacterium acnes dan Staphylococcus epidermidis memberikan hasil positif untuk beberapa jenis ester. Zona hambat terbesar diperoleh dari butil ester asam lemak hasil hidrolisis minyak jarak untuk bakteri P. acnes sebesar 20 mm dan butil ester asam lemak risinoleat untuk bakteri S. epidermidis sebesar 18 mm.

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In this research, synthesis of fatty acid esters from hydrolyzed castor oil and ricinoleic acid ester using various alcohol, namely methanol, ethanol, 2-propanol, and 1-butanol and ZnCl2 as catalyst was performed. The fatty acids to alcohols mole ratio used in the esterification reaction was 1 : 2. Esterification reaction was carried out with a time variation 4, 6, 8, 10 and 12 hours. Hydrolysis of castor oil produced 87% of fatty acid. The optimal time for the esterification reaction was 10 hours. The highest conversion percentage was obtained for ricinoleic acid methyl esters product, which was 68%. Characterization using FTIR showed the presence of group absorption of C = O esters at wavenumber 1750-1735 cm-1 and C-O esters at 1210-1163 cm-1. Emulsifier test result on esterification product showed that after 24 hours the emulsion formed was still quite stable, with the type of water-in-oil (w/o) emulsion. Methyl ester of castor oil fatty acid showed its ability as the best emulsifier among the other esters Antimicrobial activity assays against Propionibacterium acnes and Staphylococcus epidermidis showed positive results for several types of esters. The largest inhibition zone was obtained from butyl ester of castor oil fatty acid against P. acnes (20 mm) and butyl ester of ricinoleic acid against S. epidermidis (18 mm).

Abstrak :
Dalam konversi minyak kelapa sawit menjadi biodisel, minyak kelapa sawit melalui proses transesterifikasi dengan methanol untuk membnentuk biodisel dan gliserol. Namun utilitas gliserol tidak dapat dimaksimalkan dikarenakan gliserol memiliki sedikit kegunaan dibandingkan dengan biodisel. Gliserol dapat di sintesis untuk meningkatkan nilai ekonomisnya membentuk Gliserol Monostearat (GMS) sebagai agen pengemulsi. Dalam proses esterifikasi gliserol, terdapat beberapa variabel yang mempengaruhi hasil akhir seperti temperatur, dan jenis katalis yang digunakan yaitu NaOH. Riset ini dilaksanakan nutuk memahami pengaruh temperature dan jumlah katalis untuk memproduksi produk GMS dan kemampuannya untuk mengemulsi. Proses sintesis dimulai dengan mereaksikan gliserol dengan asam stearat menggunakan NaOH sebagai katalis dan variasinya jumlah 4%, 7%, dan 9%. Temperatur yang digunakan untuk reaksi menggunakan variasi 210⁰C, 220⁰C, dan 230⁰C. Untuk uji performa, produk GMS akan di bandingkan dengan agen pengemulsi komersil yaitu lecithin dan uji performa dinilai berdasarkan variasi jumlah 1.0, 2.0, dan 3.0 grams per agen pengemulsi untuk mencampurkan air dan minyak dan waktu yang dibutuhkan untuk kedua fasa terpisah Kembali. Dari riset ini dapat di konklusikan bahwa GMS dapat disintesiskan melalui observasi proses esterifikasi, membandingkan hasil FTIR, dan properti fisik produk. Hasil GMS secara kualitatif dan quantitatif dapat terbaik ditemukan pada temperature 220⁰C dan jumlah katalis NaOH 7%. GMS juga dapat mengemulsi air dan minyak, dan dibandingkan dengan lecithin, GMS dapat mengemulsi campuran air dan minyak dari lemak hewan lebih baik. ......In the reaction to convert crude palm oil into biodiesel, it undergoes the process of transesterification of the triglycerides with methanol to form biodiesel and glycerol. The utility of glycerol is not maximized since glycerol itself is considered to have less use than its primary product of biodiesel. Glycerol itself can be synthesized further to increase its economic value, to the form of Glycerol Monostearate (GMS) as an emulsifying agent. Through the process of esterification of glycerol, there are many variables at play including the operating condition of temperature, and using the catalyst of NaOH. This research is conducted to understand the effect of temperature and amount of catalyst on the production of GMS product and its ability as an emulsifier. The process of synthesis occurs with reacting glycerol and stearic acid using NaOH as a catalyst with the variation amount of 4%, 7%, and 9%. The temperature for the operating system occurs with the variation of 210⁰C, 220⁰C, and 230⁰C. For the performance test, the GMS product is compared with a commercial emulsifier, lecithin and is tested based on the amount of 1.0, 2.0, and 3.0 grams per emulsifier used to the time after oil and water mix and how long will it take until both phases separate. From this research, the conclusion of the synthesis for GMS can be done through observation of the process, the comparison of FTIR analysis, and the product physical properties. The temperature at 220°C and amount of 7% catalyst gives the highest yield, low temperature and amount of NaOH will affect the quality of the yield and high temperature and amount of NaOH will affect the quality and quantity of the yield. The product GMS can emulsify water and oil, and in comparison, with lecithin, the product itself is better at the emulsification of water to animal fat oil.

Abstrak :
Produk emulsifier lesitin merupakan agen penstabil yang baik digunakan untuk industri makanan, farmasi dan kosmetik. Dalam industri makanan, sebagain besar egen pengemulsi yang digunakan merupakan tipe emulsi minyak dalam air. Dalam penelitian ini, lesitin yang telah diekstrak dari kuning telur, dimodifikasi melalui reaksi hidrolisis enzimatik menggunakan enzim papain. Modifikasi ini akan merubah struktur molekulnya yang menjadikan lesitin lebih stabil dalam tipe emulsi minyak dalam air O/W. Penelitian ini dilakukan untuk menentukan kondisi reaksi hidrolisis yang optimum, meliputi waktu reaksi dan jumlah enzim papain yang digunakan. Penentuan hasil lesitin termodifikasi dilakukan dengan beberapa pengujian seperti uji stabilitas, bilangan saponifikasi, bilangan asam, tegangan permukaan dan zeta potensial. Dari hasil uji yang telah dilakukan, diperoleh yield lesitin tertinggi sebesar 10,42 melalui ekstraksi menggunakan pelerut etanol absolut. Stabilitas emulsi untuk jenis O/W dicapai pada lesitin dengan waktu reaksi selama 40 menit yang mampu stabil hingga 43 jam dan lesitin dengan pemakaian enzim papain sebanyak 4 yang stabil hingga 31 jam. Tegangan permukaan terendah dicapai pada lesitin hasil hidrolisis selama 40 menit dengan nilai sebesar 48,52 dyne/cm serta lesitin hasil hidrolisis dengan 2 enzim papain dengan nilai tegangan permukaan sebesar 48,68 dyne/cm. Nilai zeta potensial dari lesitin hasil hidrolisis selama 40 menit memiliki nilai 99,2 mV dan pada lesitin hasil hidrolisis dengan 2 enzim papain memiliki nilai 94,8 mV. Hasil tersebut diperoleh sebagai akibat dari putusnya rantai asam lemak tunggal pada struktur senyawa lesitin yang dapat ditunjukkan dengan instrumentasi FTIR.

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The lecithin emulsifier product is a good stabilizer agent used for food, pharmaceutical and cosmetic industries. In the food industry, most of the emulsifying emulsifier used is a type of oil in water emulsion. In this study, lecithin extracted from egg yolk was modified by enzymatic hydrolysis reaction using papain enzyme. This modification will change the molecular structure which makes lecithin more stable in the type of oil in water emulsion O W. This study was conducted to determine the optimum hydrolysis reaction conditions, including reaction time and amount of papain enzyme used. Determination of modified lecithin yield was performed by several tests such as stability test, saponification number, acid number, surface tension and potential zeta. From the results of tests that have been done, obtained the highest lecithin yield of 10,42 through extraction using absolute ethanol solvent. Emulsion stability for the O W type was achieved in 40 minute hydrolyzed lecithin which stable up to 43 hours and hydrolyzed lecithin using 4 papain enzyme with stable up to 31 hours. The lowest surface tension was achieved in 40 minute hydrolyzed lecithin with value of 48,52 dyne cm and hydrolyzed lecithin using 4 papain enzyme with surface tension value 48,68 dyne cm. The potential zeta value of 40 minute hydrolyzed lecithin has a value of 99.2 mV and on hydrolyzed lecithin using 4 papain enzyme has a value of 94,8 mV. The results are obtained as a result of the breaking of a single fatty acid chain from the structure of lecithin which can be demonstrated by FTIR instrumentation.

Abstrak :
Asam risinoleat merupakan asam lemak tak jenuh yang banyak terkandung dalam minyak jarak. Asam risinoleat dalam bentuk ester diketahui dapat dimanfaatkan sebagai emulsifier dan antimikroba. Pada penelitian ini, dilakukan esterifikasi gugus hidroksil hasil oksidasi asam lemak minyak jarak dan asam risinoleat dengan pereaksi asam laurat. Hidrolisis minyak jarak dengan katalis basa menghasilkan % randemen sebesar 86,77%. Proses oksidasi dilakukan dengan oksidator KMnO4 encer dalam suasana basa dan menghasilkan penurunan bilangan iod dari 7,02 mg/g menjadi 4,30 mg/g untuk asam lemak minyak jarak dan dari 7,02 mg/g menjadi 4,30 mg/g untuk asam risinoleat komersial. Esterifikasi dilakukan dengan bantuan katalis ZnCl2 dan rasio molar 3:1. Karakterisasi dengan LC-MS/MS menunjukkan bahwa produk ester yang terbentuk merupakan monoester. Produk ester yang diperoleh dapat berperan sebagai emulsifier setelah pengamatan selama 24 jam dengan jenis emulsi air dalam minyak. Aktivitas antibakteri dari produk ester yang diperoleh terhadap Propionibacterium acnes dan Staphylococcus epidermidis tergolong lemah. Konsentrasi sampel terkecil dari uji MIC yang dilakukan (25%), belum menunjukkan hambatan minimum terhadap kedua bakteri uji. ......Ricinoleic acid is an unsaturated fatty acid contained in castor oil. Risinoleic acid in the form of esters is known to be used as an antimicrobial and emulsifier. In this research, esterification of hydroxyl groups of oxidized castor oil fatty acids and ricinoleic acid with lauric acid was carried out. Hydrolysis of castor oil with base catalysts produces 86,77% yields of fatty acids. The oxidation process was carried out using KMnO4 in an alkaline solution and resulted in depression of iodine value from 7.02 mg/g to 4.30 mg/g for castor oil fatty acids and from 7.02 mg/g to 4.30 mg/g for commercial ricinoleic acid. Esterification was carried out using ZnCl2 as catalyst with molar ratio of 3:1. Characterization with LC-MS/MS showed that the products formed were monoester. Ester products can act as an emulsifier. The emulsion formed stable up to 24 hours and the type of emulsion was water-in-oil emulsion. The antimicrobial activity of the ester products against Propionibacterium acnes and Staphylococcus epidermidis was classified as weak. The smallest concentration applied for the MIC test (25%), has not provided minimum inhibition to both bacteria.

Abstrak :
Asam risinoleat dalam bentuk ester diketahui dapat dimanfaatkan sebagai emulsifier dan antimikroba. Pada penelitian ini, dilakukan sintesis ester asam risinoleat teroksidasi. Proses oksidasi dilakukan dengan oksidator KMnO4 encer dalam suasana basa dan menghasilkan penurunan bilangan iod untuk asam risinoleat komersial dari 7,34 mg/g menjadi 4,63 mg/g. Esterifikasi dilakukan pada asam risinoleat teroksidasi dengan pereaksi gliserol dan etilen glikol serta katalis ZnCl2 dengan rasio molar 3:1, diperoleh persen konversi ester gliserol dan ester etilen glikol sebesar 87,6% dan 82%. Karakterisasi dengan KLT menunjukkan spot pemisahan produk ester dengan nilai Rf pada rentang 0,18-0,87. Karakterisasi dengan FT-IR menunjukkan terdapatnya gugus fungsi OH, C=O dan C-O ester. Produk ester yang diperoleh dapat berperan sebagai emulsifier setelah pengamatan selama 24 jam dengan tipe emulsi air dalam minyak (w/o). Selain itu, dilakukan pula analisis mengenai potensi antimikroba pada produk ester asam risinoleat teroksidasi terhadap bakteri Gram positif Propionibacterium acnes dan Staphylococcus epidermidis menggunakan metode dilusi. ...... Ricinoleic acid in the form of an ester is known to be used as an emulsifier and antimicrobial. In this research, the synthesis of oxidized ricinoleic acid ester was carried out. The oxidation process was carried out with a thin oxidizer KMnO₄ in an alkaline solution and resulted in depression of iodine number for commercial ricinoleic acid from 7.34 mg/g to 4.63 mg/g. Esterification was carried out on oxidized ricinoleic acid with glycerol and ethylene glycol as well as ZnCl₂ catalyst with a molar ratio of  3: 1, the percent conversion of glycerol and ethylene glycol esters was 87.6% and 82%. Characterization with TLC showed the spot separation of the ester product with Rf value in the range 0.18-0.87. Characterization with FT-IR shows the functional groups OH, C=O, and C-O esters. The obtained ester product can be an emulsifier after 24 hours of observation with a water-in-oil (w/o) type emulsion. Besides, an analysis of the antimicrobial potential of ricinoleic acid esters was oxidized against Gram-positive bacteria Propionibacterium acnes and Staphylococcus epidermidis using the dilution method.

Abstrak :
Lecithin is needed as a bioemulsifier product in stabilizing agents for the food, pharmaceutical and cosmetic industries due to its renewability and as it is environmentally friendly. In the food industry, most of the emulsifiers used are the oil-in-water (O/W) type. Lecithin can be seen as a promising emulsifier product because it is extracted from egg yolk and modified by enzymatic hydrolysis reaction using the papain enzyme. This modification will change the molecular structure of the compound, which makes lecithin more stable in the oil-in-water type of emulsion. This study aims to determine the optimum amount of papain enzyme used in the hydrolysis reaction to achieve the most stable O/W lecithin emulsion type. The results show that the breaking of a single fatty acid chain from the structure of lecithin can be demonstrated by FTIR instrumentation. The fatty acids detected from the lecithin structure are shown at wavenumber 1699.45 cm-1 (C=O), 1231.44 cm-1 (C-O), 1422.45 cm-1 (C-O-H), 1092.85 cm-1 (C-C), 665.89 cm-1 (CH2), and 3400.57 (-OH in carboxylate). Determination of the modified lecithin yield was made by several tests, namely a stability test, and tests for acid value, surface tension and zeta potential. From the results of tests, the emulsion stability for the O/W type was achieved in modified-lecithin using a 4% papain enzyme dosage, with a stability duration of up to 31 hours. The lowest acid number was achieved in modified-lecithin using a 2% papain enzyme dosage with value of 10.40. The lowest surface tension was obtained in modified-lecithin using a 2% papain enzyme dosage with a surface tension value of 48.68 dyne/cm. The zeta potential of the modified-lecithin using a 2% papain enzyme had a value of -94.8 mV. These results show that the enzymatic hydrolysis of lecithin using a papain enzyme is clearly able to enhance the emulsifier properties of the lecithin produced.

Abstrak :
Ester beberapa asam lemak dengan asam risinoleat epoksida telah berhasil disintesis pada penelitian ini. Proses epoksidasi asam risinoleat dilakukan dengan asam format dan hidrogen peroksida yang membentuk asam performat secara in situ, menghasilkan penurunan angka iodium sebesar 6,47 mg/g. Proses esterifikasi dilakukan pada beberapa asam lemak yaitu asam laurat atau asam dekanoat dengan asam risinoleat epoksida menggunakan katalis ZnCl2. Rasio molar asam risinoleat epoksida dan asam lemak yang digunakan adalah 3:1. Identifikasi dengan KLT menunjukkan nilai Rf untuk ester asam laurat dengan asam risinoleat epoksida sebesar 0,64. Sedangkan nilai Rf untuk ester asam dekanoat dengan asam risinoleat epoksida sebesar 0,62. Karakterisasi dengan FTIR menunjukkan adanya pita serapan pada vibrasi ulur OH, C=O ester, dan C-O ester. Uji emulsifier menunjukkan kestabilan emulsi yang cukup baik pada pengamatan hingga 24 jam, dengan tipe emulsi water in oil (w/o). Selain itu, dilakukan analisis potensi produk ester beberapa asam lemak dengan asam risinoleat epoksida sebagai senyawa antibakteri terhadap bakteri Propionibacterium acnes dan Staphylococcus epidermidis. ......In this research, some esters of fatty acids with epoxide ricinoleic acid have been successfully synthesized. The epoxidation process of ricinoleic acid is carried out with formic acid and hydrogen peroxide which produces the in situ performic acid, resulting a decrease in iodine number of 6.47 mg/g. The esterification process was carried out on several fatty acids namely lauric acid and decanoic acid with epoxide ricinoleic acid using ZnCl2 as catalyst. The molar ratio of epoxide ricinoleic acid and fatty acid used is 3: 1. Identification with TLC shows the Rf value for lauric acid esters with epoxide ricinoleic acid of 0.64. While the Rf value for decanoic acid esters with epoxide ricinoleic acid is 0.62. Characterization with FTIR showed the presence of absorption bands on stretching OH, C=O ester, and C-O ester vibrations. Emulsifier test shows the stability of the emulsion is quite good at observations up to 24 hours, with the type of water in oil emulsion (w/o). In addition, an analysis of the antibacterial potential of several fatty acid ester products with epoxide ricinoleic acid against Propionibacterium acnes and Staphylococcus epidermidis was carried out.

Abstrak :
Pada penelitian ini dilakukan sintesis enzimatik ester asam lemak hasil hidrolisis minyak kelapa maupun asam dekanoat dengan gliserol menggunakan pelarut n-heksana dan buffer fosfat 0,05 M pH 8. Dalam reaksi ini digunakan katalis lipase Candida rugosa. Minyak kelapa dihidrolisis menggunakan KOH dalam alkohol dan asam lemak hasil hidrolisis diisolasi dan digunakan untuk reaksi esterifikasi dengan gliserol. Juga dilakukan esterifikasi asam dekanoat dengan gliserol. Perbandingan mmol antara asam lemak dengan gliserol yang digunakan pada reaksi esterifikasi berturut-turut sebesar 1:1, 1:2, 1:3, dan 1:4. Persen konversi tertinggi yang diperoleh pada perbandingan mol 1:4 yaitu 78,5 untuk ester gliserol dekanoat dan 55,4 untuk ester hidrolisat minyak kelapa. Karakterisasi produk esterifikasi dengan FTIR menunjukkan bahwa ester gliserol asam lemak hasil hidrolisis minyak kelapa maupun asam dekanoat telah berhasil terbentuk, yang ditandai dengan terdapatnya gugus C=O ester pada bilangan gelombang 1750-1739 cm-1. Terhadap produk ester yang dihasilkan dilakukan uji aktivitas antimikroba terhadap bakteri Propionibacterium acnes dan Staphylococcus epidermidis dengan metode difusi cakram. Hasil uji aktivitas antimikroba kedua sampel ester dan asam lemaknya menunjukkan adanya aktivitas antimikroba dengan diameter hambatan tertinggi sebesar 17 mm pada variasi perbandingan mol 1:4. Dilakukan pula uji emulsifier dengan mencampurkan minyak dan air dalam variasi volume tertentu. Hasil uji emulsifier menunjukkan kedua ester dapat menyatukan minyak dengan air. Kestabilan emulsi yang terbentuk lebih tinggi untuk penggunaan ester gliserol hidrolisat asam lemak minyak kelapa dibandingkan dengan ester gliserol dekanoat.

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In this research, enzymatic synthesis of fatty acid esters obtained by hydrolysis of coconut oil and decanoic acid with glycerol using n hexane solvent and phosphate buffer 0,05 M pH 8. In this reaction was used Candida rugosa lipase catalyst. Coconut oil is hydrolyzed using KOH in alcohols and the fatty acid of the hydrolysis product is isolated and used for the esterification reaction with glycerol. The esterification of decanoic acid with glycerol was also carried out. The mmol ratio between fatty acid and glycerol used in the esterification reaction was 1 1, 1 2, 1 3, and 1 4, respectively. The highest conversion percentage obtained at the mole ratio of 1 4 was 78.5 for the glycerol ester and 55.4 for the coconut oil hydrolysate ester. The characterization of esterification product with FTIR indicates that fatty acid glycerol ester from hydrolyze of coconut oil and decanoic acid has been successfully formed, characterized by the presence of C O ester group at wave number 1750 1739 cm 1. Against the resulting ester product, antimicrobial activity was tested on the bacteria Propionibacterium acnes and Staphylococcus epidermidis by disc diffusion method. The results of the antimicrobial activity test of both ester and fatty acid samples showed the presence of antimicrobial activity with the highest resistance diameter of 17 mm in the variation of 1 4 mole ratio. There is also an emulsifier test by mixing oil and water in certain volume variations. Emulsifier test results show that both esters can unite oil with water. The higher emulsion stability is higher for the use of ester glycerol hydrolysate fatty acid coconut oil compared to the ester of glycerol decanoic.

Abstrak :
Pada penelitian ini, ester asam risinoleat disintesis melalui hidrolisis minyak jarak yang teroksidasi secara kimiawi melalui tiga tahapan reaksi yaitu hidrolisis basa, oksidasi dengan alkali KMnO4, dan esterifikasi menggunakan katalis ZnCl2 dengan variasi alkohol yaitu metanol, etanol, isopropanol, dan 1-butanol. Perbandingan mol asam lemak dan alkohol yang digunakan dalam esterifikasi adalah 1: 2. Proses yang sama dilakukan dengan asam risinoleat komersial untuk perbandingan. Hidrolisis basa minyak jarak menghasilkan 84% rendemen asam lemak. Oksidasi ikatan rangkap asam lemak hasil hidrolisis terlihat dari penurunan bilangan iodium dari 43,38 mg / g menjadi 13,11 mg / g dan peningkatan intensitas serapan gugus -OH pada spektrum FTIR. Persentase konversi esterifikasi tertinggi diperoleh pada esterifikasi menggunakan etanol yaitu 98%. Hasil karakterisasi menggunakan FTIR menunjukkan bahwa serapan gugus C = O ester pada 1750-1735 cm-1 dan C-O-C pada 1300-1000 cm-1 membuktikan keberhasilan esterifikasi. Produk ester diuji kemampuannya sebagai pengemulsi dan hasilnya setelah 24 jam masih dipertahankan bentuk emulsi dengan jenis emulsi air dalam minyak (w / o). Kemampuan sebagai pengemulsi paling baik ditunjukkan oleh metil ester. Hasil uji aktivitas antimikroba terhadap Propionibacterium acnes dan Staphylococcus epidermidis memberikan hasil positif untuk semua jenis ester, dengan zona hambat terbesar diperoleh dari isopropil ester untuk bakteri P. acnes sebesar 16 mm dan butil ester untuk bakteri S. epidermidis sebesar 17 mm .
In this study, the ricinoleic acid ester was synthesized through the hydrolysis of castor oil which was chemically oxidized through three stages of reaction, namely alkaline hydrolysis, oxidation with KMnO4 alkaline, and esterification using ZnCl2 catalyst with variations of alcohol, namely methanol, ethanol, isopropanol, and 1-butanol. The mole ratio of fatty acids and alcohols used in esterification is 1: 2. The same process is carried out with commercial ricinoleic acid for comparison. The alkaline hydrolysis of castor oil produced 84% fatty acid yield. The oxidation of fatty acid double bonds as a result of hydrolysis can be seen from a decrease in the iodine number from 43.38 mg / g to 13.11 mg / g and an increase in the absorption intensity of -OH groups in the FTIR spectrum. The highest percentage of esterification conversion was obtained in esterification using ethanol, namely 98%. The results of characterization using FTIR showed that the absorption of C = O ester groups at 1750-1735 cm-1 and C-O-C at 1300-1000 cm-1 proved the success of esterification. The ester product was tested for its ability as an emulsifier and the result after 24 hours was still retained the emulsion form with the water-in-oil (w / o) emulsion type. The ability as an emulsifier is best demonstrated by the methyl ester. The results of the antimicrobial activity test against Propionibacterium acnes and Staphylococcus epidermidis gave positive results for all types of esters, with the largest inhibition zone obtained from isopropyl ester for P. acnes bacteria at 16 mm and butyl ester for S. epidermidis bacteria at 17 mm.