Judul: Penggunaan Khitosan Sebagai Antimikroba pada Bakso Daging Sapi yang Dibuat dengan Penambahan Wortel
Abstrak: Meatball is a perishable meat product, therefore it needs some preservative to make it has a longer shelf-life. In this study, the method used was factorial design with completely randomized design (CRD) as basic. Chitosan as natural preservative was added in meatball processing as much as 0%, 0.1%, and 0.3%. In addition, 5% of carrort was added too. Chitosan antibacterial activity was analyzed once, meanwhile meatball’s micribiological analysis (S. aureus, E. coli, and Salmonella), pH, and aw was conducted on day 0, 4, 8, and 12. One hundred percent chitosan was more effective to inhibit E. coli than S. aureus and Salmonella. Fifty percent of chitosan can reduce population of E. coli from 3.65 x 1011 to 2.66 x 108. The addition of 0.1% and 0.3% chitosan in meatball processing eliminized E. coli population since day 0 until 12 days storage. There was no interaction between chitosan level and storage period towards the meatball’s population of S. aureus, Salmonella, and aw value. Meatball’s pH decreased on day 12. Meatball contains 102.45 IU beta-carotene and contributes 1.46% and 2.05% women’s and men’s need of vitamin A, respectively. Chitosan can replace chemical preservative in meatball manufacturing and carrot addition can supply human’s need of vitamin A.
Keyword: 

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.
Keyword: 

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