Judul: Extraction and Characteristic of Collagen and Nanoparticle Collagen from the Skin of Stingray Fish (Pastinachus solocirostris) as Ingredient of Cosmetics.
Abstrak: Isolation of collagen from the skin of stingray fish (Pastinachus solocirostris) has been successfully conducted with three stages: first soaked in 0.05 M NaOH with a sample/solution ratio of 1:10 (w/v) for 6 hour, second soaked in 0.1 M acetic acid with a sample/solution ratio of 1:6 (w/v) for 2 hour, and third extraction with destilated water at temperature 40 C for 2 hour with a yield of 14.475 % (wet base). Nanoparticle collagen was made with desolvation method using etanol as a desolvating agent with a collagen solution/etanol ratio of 1:1. Yield of nanoparticle collagen was 9.64% (wet base) with particle size of 185.24 nm. Collagen and nanoparticle collagen is in the form of white powder with whiteness degree 72.48% and 60.03%, respectively. Protein is the major component in collagen and nanoparticle collagen (86.97% and 86.18%) with trace amount of ash (0.17% and 0.13%) and fat (0.19% and 0.25%), respectively. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns, amino acid composition, and fourier transform infrared (FTIR) spectra of both collagen and nanoparticle collagen were characterized as type I collagens. Nanostructural analysis of collagen and nanoparticle collagen by Scanning Electron Microscopy (SEM) shows that both were separate aggregates. Other characteristics of collagen and nanoparticle collagen were: Tmax of 165.88 C and 156.63 C; Viscosity 292.33 cP dan 110 cP; pH 5.00 dan 4.93; respectively. Collagen has highest solubility at pH 7 and the isoelectric point at pH 6, 9, and 10. Therefore, nanoparticle collagen has highest solubility at pH 3 dan and the isoelectric point at pH 6. Collagen and nanoparticle collagen from skin of stingray fish (Pastinachus solocirostris) has a characteristic for a potential use as a cosmetic ingredient.
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Judul: Isolasi dan Karakterisasi Kolagen Nanopartikel dari Kulit Ikan Cucut Bambu (Chiloscyllium punctatum)
Abstrak: Collagen is one type of proteins contained in the animal’s body with proportion about 30 % of total proteins whole body. Utilization of waste from shark skin to produce nanoparticle collagen is one alternative to increase market value of this waste. The purpose of the research was to characterize nanoparticle collagen resulted the best treatment of shark fish skin using acetic acid. The proximate composition of shark fish skin (Chiloscyllium punctatum) contained the water of 58 %, ashes 14,43 %, proteins 29,77 %, and fats 0.16 %. Rendemen produced with a solvent acetic acid 0,1 N; 0,2 N; and 0,3 N is 1,49 %, 5,37 %, and 12,52 % with best rendemen is 12,52 % having a pH 4,6. PSA Testing nanoparticle collagen from treatment best acetic acid having size of particles average of 146,71 nm and the result of FTIR found A-amide of 3310, 3333, 3364, and 3394 cm-1, B-amide of 2939 cm-1, I-amide of 1651 cm-1, II-amide of 1543 cm- 1, and III-amide of 1242 cm-1 on nanoparticles collagen produced.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh.
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. ,,,
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular.