Judul: Aktivitas Antioksidan Lignin dari Lindi Hitam Kraft Berbahan Baku Kayu Acacia mangium
Abstrak: The use of black liquor, spent liquor produced from pulp processing, can be increased through isolation and purification to produce various useful products. One of the components in the liquor is lignin. Lignin was isolated from black liquor by precipitation using H2S04 20%. Lignin has potential application as an antioxidant. Phenolic hydroxyl groups in lignin can scavenge the free radicals. In this study, antioxidant activity of lignin, which is isolated from black liquor of Acacia mangium wood as the raw material, was examined by diphenyl picrylhydrazyl (DPPH) method. Lignin would scavenge the DPPH free radicals and change the color from purple to pale yellow of diphenyl picrylhydrazine. The change of color intensity was measured by ultraviolet-visible spectrophotometer. The result showed that lignin had strong antioxidant activity with 50% inhibition concentration (IC50) value of 18 ppm, higher than 3,5-di(t-butyl)-4- hydroxytoluene with IC50 value of 1880 ppm. Antioxidant activity of lignin was increasing with the increasing phenolic hydroxyl content and the decreasing lignin molecular weight
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Judul: Uji aktivitas antioksidan lignin dari tandan kosong kelapa sawit
Abstrak: The increasing oil palm plantation will increase the amount of oil palm production. One of the solid waste from oil palm industry is empty fruit bunch (EFB) that contain lignocellulose. This research used lignin content in EFB as an antioxidant. Lignin delignification from EFB was done by pulping organosolv method using ethanol. Lignin antioxidant activity was characterized with DPPH method (1,1-diphenyl-2-picrylhydrazyl) as free radical, measured as IC50 (inhibition concentration 50%). Lignin yield was 9,09%; lignin content 76,57%; and fourier transform infrared (FTIR) spectrum indicated the lignin. Phenolic hydroxyl and molecular weight lignin were also determine the lignin antioxidant activity. This result pointed out that the lignin have phenolic structure of type 2 and 3 each 0,4% and the molecular weight is 4005 g/mol. Butylated hydroxytoluene (BHT), a commercially chemical antioxidant, was used as a positive control. The IC50 of lignin is 50,2 ppm, while IC50 that of BHT is 1883 ppm. This result shows that antioxidant activity of lignin is higher than that of BHT.
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Judul: Karakteristik Anatomi Skelet Kepala Buaya senyulong (Tomistoma schlegelii).
Abstrak: Buaya sepit atau senyulong (Tomistoma schlegelii) merupakan jenis buaya asli Indonesia yang berhabitat di sungai-sungai Sumatera, Kalimantan, dan juga pedalaman Sulawesi. Salah satu ciri khas buaya senyulong adalah bentuk moncong yang runcing dan sempit, namun hingga saat ini informasi mengenai struktur skelet kepala buaya senyulong sangat terbatas. Penelitian ini bertujuan untuk mempelajari karakteristik anatomi skelet kepala buaya senyulong yang dikatikan dengan fungsi dan perilakunya. Penelitian dilakukan secara eksploratif dengan melakukan pengamatan, pencatatan, dan pengambilan gambar dari skelet kepala buaya senyulong. Skelet kepala berukuran panjang 70 cm, lebar 29 cm, dan tingggi 17 cm dengan permukaan kasar pada os nasale, os frontale, os maxilla, os mandibula, os lacrimale, os jugale. Jumlah gigi pada buaya ini sebanyak 78 buah, terdiri dari 4 buah gigi premaxila, 16 buah gigi maxila, dan 19 buah gigi mandibula. Pada regio orbitalis ditemukan dua pasang fenestrae temporales yang berkembang baik. Fenestra supratemporale merupakan lubang oval yang membentang di sepanjang os parietale. Fenestra infratemporale berbentuk segitiga dan dibatasi oleh os squamosum, os postorbitale, os jugulare, dan os quadratum. Os mandibula hewan ini mempunyai symphysis mandibularis yang panjang yaitu garis yang melintang di corpus mandibulae. Secara fungsional ukuran symphysis mandibularis berkaitan dengan adaptasi hewan terhadap diet makan.
Keyword: kepala, moncong, Tomistoma schlegelii