Judul: Karakteristik Mikrobiologis Bakso Sapi  yang Diawetkan dengan Substrat Antimikroba dari  Lactobacillus plantarum  1A5 pada Penyimpanan Suhu Ruang
Abstrak: The objective of this research was to observe the effect of antimicrobial substrate of Lactobacillus plantarum 1A5 origin as a natural preservative on beef meatball at room temperature storage. The complete randomized design of two factors was used to analyze the effect of antimicrobial substrate microbiological characteristics of beef meatball. The treatments and control were storage at room temperature (± 280 C) with antimicrobial substrat 100 % and 0 % for 0 hour, 9 hours, and 18 hours after conditioning process. The variables were total plate count, quantitative of Staphylococcus aureus, quantitative of Escherichia coli and qualitative of Salmonella spp. The result of this research showed that there were decreasing (P<0,05) of total microbe, quantitave of Staphylococcus aureus and quantitative of Escherichia coli were decreasing (P<0,05) during room storage until 9 hours. Salmonella spp. test showed negative result.
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Judul: Karakteristik Mutu  Bakso Sapi dengan Penggunaan Supernatan yang Mengandung Antimikroba  dari  Lactobacillus plantarum 1A5 pada Penyimpanan Suhu Dingin
Abstrak: Meatball is one of the meat product with good nutrient and most of the people like this product. Meatball is perishable, therefore it needs to add some preservative to make the meatball has a longer shelf-life. Most of the meatball still using preservative that made of chemical. But recently, people prefer to natural preservative than chemical, because its more safety to consume. This natural preservative is coming from lactic acid bacteria and its capable to obtaining an antimicrobial substance, bacteriosin, hidrogen peroxside, and other metabolism that effect the consumer. The aim of this research is to test an effect of free cell supernatant from antimicrobial Lactobacillus plantarum 1A5 as natural preservative to microbiology, physical, chemical, and organoleptic characteristic at refrigerator temperature storage. This research was divided into two phase, the first research and second research. The first research made mixed culture and second research made beef meatball then analysed in physic, chemical, organoleptic and microbiology test in cold storage in 0, 5, and 10 days.The experiment design used random complete design with factorial pattern 2x3 on three repeat. First factor was antimicrobial supernatan usage and control, and second factor was cold storage in 0, 5, and 10 days. The observed parameters physical and chemical were pH, TAT, texture, water content and water activity. Organoleptic test on color of beef meatball, flavor, texture, mucus and taste. Microbiology test on Total Plate Count (TPC). Physical, chemical, and microbiology data was analysed by Analysis of Variance (ANOVA) with matched assumption, if wasn’t matched it used Kruskal-Wallis method and so also the organoleptic test.he result showed that the different storage of beef meatball influence significant on TAT, water activity, and TPC, but did not influence significant on pH value, water content, and texture.
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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