Judul: Pemanfaatan Redistilat Asap Cair Cangkang Kelapa Sawit sebagai Bahan Pengawet Alami pada Bakso Sapi
Abstrak: The misapplication of chemicals, such as formaldehyde, for preservative is still found in processed food ingredients. The use of these materials can be replaced by redistilled liquid smoke from oil palm shells. Identification using gas chromatography-mass spectrometer showed that there were no harmful compounds such as tar and polycyclic aromatic hydrocarbons. Acid level and pH of redistilled liquid smoke on 80 °C possess better result with the respectively values were 5.14% and 2.26. The LC50 value with brine shrimp lethality test method is 0.16%. Inhibition zone on the antibacterial test to Staphylococcus aureus with redistilled liquid smoke on 0.1% and 0.8% were respectively 6.11 mm and 6.08 mm while to Escherichia coli were respectively 0 mm and 6.95 mm. The inhibition zone redistilled liquid smoke was lower than 100 ppm chloramphenicol, which were 14.17 mm on S. aureus and 12.60 mm on E. coli. Redistilled liquid smoke with concentration of 0.8% was better than the concentration of 0.1% in inhibiting the growth of total microbial on the meatballs. The addition of redistilled liquid smoke was able to inhibit the growth of microbial up to 18 hours at room temperature.
Keyword: Bogor Agricultural University (IPB), redistilled liquid smoke, oil-palm shells, natural preservative, meatball

Judul: Kajian Penggunaan Asap Cair Tempurung Kelapa terhadap Daya Awet Bakso Ikan
Abstrak: The study investigated safeties and antibacterial activity of coconut shell liquid smoke and its applications of fishball preservation. The safeties of liquid smoke studied by identification of volatile compounds of liquid smoke by means of Gas Chromatography-Mass Spectroscopy (GC-MS) and determination acute toxicity of liquid smoke. A high number of compounds was detected. They were identified as ketones, carbonyl, acids, furan and pyran derivatives, phenol and derivatives, guaiacol and derivatives, syringol and derivatives, and alkyl aryl ethers. Neither benzo[a]pyrene nor other polycyclic aromatic compounds with carcinogenic properties were found in this liquid smoke. Acute toxicity test of these product assessed by determination of LD50 dose (the dose which causes the death of half the test animals). Results indicated that LD50 dose of this liquid smoke are more than 15.000 mg/kg body weight of mice. The Minimum Inhibitory Concentration (MIC) of liquid smoke against Pseudomonas aeruginosa and Staphylococcus aureus determined using broth or agar dilution methods. Liquid smoke showed antibacterial activities againts P. aeruginosa and S. aureus with MIC value 0,22% and 0,40%, respectively. Applications of 2,5% liquid smoke in fishball at 27–28 0C increased shelflife from 16 to 32 hours, whereas at 4±1 0C until 20 days storage were better accepted, and retarded the decreased of pH and moisture content compared to control. The results indicated that liquid smoke was an effective preservative agent for fishball.
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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. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular