Metode Pemurnian Lipase Kecambah Biji Wijen (Sesamun indicum) Menggunakan Immobilized Metal Affinity

A high-density matrix was prepared by coating an alumina particle with agarose using an emulsion technique. Iminodiacetic acid was immobilized onto this matrix. Charging this matrix with copper created a useful chromatography matrix for purification of indigenous sesame sprout lipase. Butanediol diglycidyl ether (BDGE) was used as spacer arm. Factors such as, adsorption pH, BDGE concentration in matrix preparation, concentration of NaCl and imidazole were investigated. Based on both the binding capacity of matrix and the eluate adsorbed lipase, the optimum BDGE concentration and the adsorption pH were found about 40 % and 7, respectively. However, an increase in NaCl concentration in adsorption buffer from 0.5 to 1.5 M resulted in 2 times decrease in the ratio between adsorbed lipase and adsorbed total proteins. More interestingly, immobilization of Cu on this matrix was highly effective in the purification lipase, since lipase could be easily eluted from matrix using low concentration of imidazole (10 mM). Enzyme recovery and purification factor were 68% and 9.4, respectively.ABSTRAKAdsorbent matrik yang mempunyai densitas tinggi dibuat dengan melapisi permukaan partikel alumina dengan agarose. Permukaan matrik dimodifikasi dengan iminodiacetic acid (IDA) menggunakan butanediol diglycidyl ether (BDGE). Gugus karboksil pada IDA digunakan untuk mengamobilisasi Cu dan digunakan untuk memisahkan indigenous lipase dari kecambah biji wijen. Kemampuan matrik tersebut pada pemurnian lipase dievaluasi. Faktor yang dipelajari adalah pengaruh konsentrasi BDGE pada preparasi matrik, pH adsorpsi, konsentrasi NaCl dan konsentrasi imidazol. Hasil penelitian menunjukkan bahwa kondisi optimum terjadi pada perlakuan konsentrasi BDGE 40 % danpH adsorpsi 7. Kenaikan NaCl dalam buffer dari 0,5 ke 1,5 M menyebabkan penurunan perbandingan lipase teradsorpsidan total protein teradsorpsi sebesar 2 kali. Dari penelitian ini dapat disimpulkan bahwa amobilisasi Cu pada matrik efektif digunakan untuk memurnikan lipase dan lipase dapat dimurnikan dengan hasil recovery sebesar 68% dan faktor purifikasi sebesar 9,4

Stabilitas Mikroemulsi Fucoxanthin dan Efektifitasnya dalam Menghambat Foto Oksidasi Vitamin C pada Model Minuman

Fucoxanthin microemulsion was prepared by dissolvingfocoxanthin in Virgin Coconut Oil (VCO) and mixture of surfactants (Tween 20:Tween 80:Span 80 = 92:5.5:2.5 (% v/v)with oil-surfactan ratio 15:85 v/v, then added with water until the concentration reaching 600 ppm fucoxanthin. The fucoxanthin microemulsions were analyzed the stability towards pH, the samples were diluted 50 times and 100 times with water media and citrate buffer (pH:3.5; 4.5 and distilled water pH 6.5). Subsequently, the samples were tested for centrifugation and storage stability at room temperature. The appearance of fucoxanthin microemulsion stability was measured with spectrometer UV/VIS at a wavelength of 458 nm. The beverage models were made of vitamin C (450 mg/L), citric acid (1%) and sucrose (6%). Fucoxanthin microemulsions were added to the beverage model that had been diluted 50 time and 100 time with distilled water pH 6.5. Subsequenly, the samples were added 5 ppm erytrhosine as a sensitizer and without erytrhosine as control. The beverage models were exposed to flourescent light with an intensity of 2000 lux. Vitamin C concentration was mesured by the method of riboflavin-sensitized photodynamic UV spectrophotometry every 2 hours. Fucoxanthin microemulsions were stable at pH 3.5 to 6.5 and even the heating treatment, centrifugation and dilution. Fucoxanthin microemulsion above 6 ppm was not effective in inhibiting degradation rate of vitamin C on photooxidation in beverage models.ABSTRAKMikroemulsi fucoxanthin dibuat dengan melarutkanfucoxanthin dalam VCO dan ditambah surfaktan (Tween 20:Tween 80:Span 80 = 92:5,5: 2,5 (% v/v), dengan rasio minyak-surfaktan 15:85 v/v, kemudian ditambahkan air hingga konsentrasi fucoxanthin mencapai 600 ppm. Mikroemulsi fucoxanthin dianalisis stabilitasnya meliputi pengujian stabilitas terhadap pH yang dilakukan pengenceran 50 kali dan 100 kali dengan media air dan buffer sitrat (pH: 3,5; 4,5 dan aquades pH 6,5). Selanjutnya sampel-sampel tersebut diuji stabilitasnya terhadap sentrifugasi dan penyimpanan pada suhu kamar. Stabilitas kenampakan mikroemulsi fucoxanthin diukur absorbansinya dengan spektrometer UV/VIS pada panjang gelombang 458 nm. Model minuman merupakan larutan yang tersusun dari vitamin C (450 mg/L), asam sitrat (1%) dan sukrosa (6%). Mikroemulsi fucoxanthin yang ditambahkan ke dalam model minuman yang telah diencerkan 50 kali dan 100 kali dengan aquades pH 6,5. Selanjutnya ke dalam sampel ditambahkan 5 ppm eritosin sebagai sensitiser atau tanpa penambahan eritrosin sebagai kontrol. Sampel tersebut kemudian diletakkan di dalam generator oksigen singlet yang telah dilengkapi lampu fluoresens dengan intensitas cahaya 2000 lux. Konsentrasi vitamin C diukur dengan metode riboflavin-sensitized photodynamic UV spectrophotometry dengan interval 2 jam. Mikroemulsi fucoxanthin yang diperoleh stabil pada pH 3,5 sampai 6,5 dan meskipun telah mengalami perlakuan pemanasan, sentrifugasi dan pengenceran. Mikroemulsi fucoxanthin di atas 6 ppm tidak efektif lagi dalam menghambat laju kerusakan vitamin C pada foto oksidasi dalam model minuman

Efektivitas Mikroemulsi O/W Dengan Surfaktan Non Ionik Dalam Menghambat Fotooksidasi Vitamin C Pada Model Minuman

The objective of this study was to obtain the effectiveness of oil-in-water (o/w) microemulsion using nonionic surfactans to improve the stability and inhibit the deterioration rate of vitamin C in beverage model systems caused by photooxidation. O/W microemulsions were formulated with oil-surfactan ratio (15:85 v/v), with surfactant mixture consisting of Tween 80:Span 80:Tween 20 = 92:5.5:2.5 (% v/v) and water content 65%. O/W microemulsions were subjected to stability towards pH and dilution. The dilution were done by dilute microemulsions with water and citrate buffer (pH: 3.5; 4.5 and water pH 6.5) with proportion 1:1, 1:9 and 1:99. The microemulsios were tested the stability on heating treatment at 105 °C for 5 hours and during storage for 8 weeks at room temperature. The baverage models were vitamin C solution (450 mg/L, citric acid (1%) and sucrose (6%). The o/w microemulsions added in the beverage models were microemulsion that had been diluted 50 and 100 times with water pH 6.5. The beverage model was added with 5 ppm erythrosin as sensitizer and without erythrosin as control. The models were exposed to fl ourescent light with an intensity of 2000 lux. Vitamin C concentration was mesured by the method of ribofl avin-sensitized photodynamic UV spectrophotometry every 2 hours. The o/w microemulsion was stable at pH 3.5 to 6.5 and dilution (1:1, 1:9, and 1:99), heating and storage. The o/w microemulsions which were diluted 100 times effectively increased the stability of vitamin C, but the o/w microemulsions diluted 50 times was more efective to inhibit the rate of distruction of vitamin C due to photooxidation in beverage model

Metode Pemurnian Lipase Kecambah Biji Wijen (Sesamun Indicum) Menggunakan Immobilized Metal Affinity

A high-density matrix was prepared by coating an alumina particle with agarose using an emulsion technique. Iminodiacetic acid was immobilized onto this matrix. Charging this matrix with copper created a useful chromatography matrix for purification of indigenous sesame sprout lipase. Butanediol diglycidyl ether (BDGE) was used as spacer arm. Factors such as, adsorption pH, BDGE concentration in matrix preparation, concentration of NaCl and imidazole were investigated. Based on both the binding capacity of matrix and the eluate adsorbed lipase, the optimum BDGE concentration and the adsorption pH were found about 40 % and 7, respectively. However, an increase in NaCl concentration in adsorption buffer from 0.5 to 1.5 M resulted in 2 times decrease in the ratio between adsorbed lipase and adsorbed total proteins. More interestingly, immobilization of Cu on this matrix was highly effective in the purification lipase, since lipase could be easily eluted from matrix using low concentration of imidazole (10 mM). Enzyme recovery and purification factor were 68% and 9.4, respectively

Formulasi dan Stabilitas Mikroemulsi O/W sebagai Pembawa Fucoxanthin

The objective of this study was to obtain a clear and stable oil-in-water (o/w) microemulsion containing fucoxanthinwhich is intended for aqueous food system application. Virgin coconut oil (VCO) was used as the oil phase andcombination of Tween 80, Tween 20 and Span 80 were selected as nonionic surfactant having high, medium, and lowHLB (Hydrophilic-Lipophilic Balance) values, respectively. The o/w microemulsions were formulated to have the Þ nalHLB values of 13.5, 14.0, and 14.5. For each HLB value, three different microemulsion formulas were determined. Allof the formulated microemulsions were then subjected to oven heating at 105 oC for 5 hour, centrifugation at 4500 rpmfor 30 min, incubation at different pH (3.5, 4.5, and 6.5), water dilution, and photooxidation to evaluate its stability.The most stable microemulsion was then selected and used to deliver fucoxanthin as a hydrophobic antioxidant inaqueous system. Photo-oxidation was performed by exposing the microemulsions under ß uorescent light at 4,000 luxfor up to 4 hours at room temperature. Peroxide values were measured every hour using ferric thiocyanate method.Stable o/w microemulsions were obtained when its HLB value was 14.5, the ratio of oil:surfactants was 3:17, andthe ratio of (oil + surfactants) : water was 35 : 65. The ratio of Tween 80 : Tween 20 : Span 80 was 92.0 : 2.5: 5.5. Fucoxanthin microemulsion was remained stable at pH range from 3.5 to 6.5 even after heating treatment,centrifugation, and water dilution. However, there were increased peroxide values of these microemulsions after being subjected to photooxidation. The presence of fucoxanthin (over 12 ppm) in the microemulsion could not effectively inhibit photooxidation of the o/w microemulsion.ABSTRAKTujuan penelitian ini adalah untuk memperoleh mikroemulsi minyak dalam air (o/w) yang mengandung fucoxanthinyang stabil dan jernih untuk diaplikasikan dalam sistem makanan aqueous. Virgin coconut oil (VCO) digunakansebagai fase minyak dan kombinasi Tween 80, Tween 20 dan Span 80 sebagai surfaktan non ionik yang masingmasingmempunyai nilai HLB (Hydrophilic-Lipophilic Balance) tinggi, medium dan rendah. Formulasi mikroemulsio/w ditentukan nilai HLB akhir masing-masing 13,5; 14, dan 14,5. Masing-masing nilai HLB tersebut ditentukan tigaformula yang berbeda. Semua formulasi mikroemulsi kemudian dipanaskan dalam oven pada suhu 105 oC selama 5jam, disentrifugasi pada kecepatan 4500 rpm selama 30 menit, diinkubasi pada pH yang berbeda (3,5; 4,5 dan 6,5),diencerkan dengan akuades dan stabilitas diuji secara fotooksidasi. Mikroemulsi paling stabil selanjutnya dipilih dandigunakan untuk pembawa fucoxanthin sebagai antioksidan hidrofobik dalam sistem aqueous. Fotooksidasi ditentukandengan menempatkan mikroemulasi di bawah sinar ß ouresensi 4000 lux selama 4 jam pada suhu ruang. Angkaperoksida diukur setiap jam menggunakan metode feri thiosianat. Mikroemulsi o/w yang stabil diperoleh pada HLB14,5 dengan rasio minyak : surfaktan = 3 : 17 dan rasio minyak + surfaktan : air = 35 : 65. Rasio Tween 80 : Tween 20: Span 80 adalah 92.0 : 2.5 : 5.5. Mikroemulsi fucoxanthin yang diperoleh stabil pada pH 3,5 sampai 6,5 dan bahkansetelah perlakuan pemanasan, sentrifugasi dan pengenceran. Namun angka peroksida meningkat selama fotooksidasi.Fucoxanthin dalam mikroemulasi lebih dari 12 ppm tidak efektif untuk menghambat fotooksidasi dalam mikroemulsio/w.

Microemulsion Characteristics of Oil-in-Water with Surfactants as α-tocopherol Carriers

Microemulsions are relatively stable carrier agents for bioactive components. This study aimed to determine the characteristics of oil-in-water (O/W) microemulsions as carriers of α-tocopherol compounds in variations of α-tocopherol concentration, pH, and dilution. The O/W microemulsion was made from a mixture of surfactants (Tween 80, Tween 20, and Span 80) with virgin coconut oil (VCO) in a ratio of 85:15 with a total volume of 5 mL added with 10 mL of distilled water. The research used a randomized block design (RBD). The data were analyzed using ANOVA and continued with Tukey's test and regression analysis. Treatments in microemulsion were the addition of α-tocopherol with concentrations of: 0.25, 1.50, 1.75 and 2.0%. Observations were made on the turbidity index values, appearance, droplet diameter, and microemulsion stability. In addition, observations were made on the stability of the microemulsion at variations of pH (4.5, 5.5, 6.5), and dilution (10, 50, and 100 times). The results showed that the microemulsion was able to carry α-tocopherol compounds up to a concentration of 2% with a turbidity value reaching 0.1036 ± 0.0033% with a transparent appearance. A mixture of three surfactants (Tween 80, Tween 20 and Span 80) has the ability to increase droplet stability. The α-tocopherol microemulsion had a droplet diameter below 30 nm and stayed stable against the effects of centrifugation at pH 4.5 with dilutions up to 50 times and remained stable upto pH 6.5 with dilutions between 50 – 100 times