Judul: Physicochemical and Microbiological Characteristics of Meatballs Coated with Aloe Vera Gel (Aloe Vera Linn) as an Edible Coating
Abstrak: Bakso merupakan produk yang mudah mengalami kerusakan akibat aktivitas mikroba sehingga diperlukan bahan pengawet, seperti gel lidah buaya yang mengandung senyawa bioaktif. Penelitian ini bertujuan untuk menguji sifat fisikokimia dan mikrobiologis bakso daging sapi yang dilapisi gel lidah buaya. Rancangan percobaan yang digunakan adalah rancangan acak kelompok berdasarkan periode pembuatan bakso dengan dua faktor perlakuan (3 x 2). Faktor pertama adalah pelapisan gel lidah buaya pada bakso sapi dengan 3 taraf perlakuan yaitu 0% lidah buaya (kontrol); 50% lidah buaya; dan 100% lidah buaya. Faktor kedua adalah penyimpanan dalam suhu lemari es (0 dan 7 hari). Hasil analisis fisikokimia menunjukkan bahwa perlakuan gel lidah buaya dan lama penyimpanan tidak berpengaruh nyata terhadap nilai aw dan kadar air, tetapi perlakuan gel lidah buaya berpengaruh terhadap nilai pH bakso (p < 0,05). Perlakuan gel lidah buaya dan lama penyimpanan tidak memengaruhi jumlah E.coli bakso, tetapi berpengaruh terhadap nilai total plate count, serta positif Salmonella sp. pada bakso kontrol setelah penyimpanan hari ke-7. Dapat disimpulkan bahwa pemberian gel lidah buaya sebagai edible coating bakso memengaruhi pH bakso, serta memperbaiki mutu mikrobiologis bakso., Meatballs are easily damaged due to microbial activity, therefore preservatives are needed, such as aloe vera gel containing bioactive compounds. This study was aimed to examine physicochemical and microbiological characteristics of beef meatballs coated with aloe vera gel. The experimental design to be used was a randomized block designed with two factors of treatments. The first factor are the levels of aloe vera gel that consist of 0%, 50%, and 100%. The second factor is storage in refrigerator temperature (0 and 7 days). The results of physicochemical analysis showed that the aloe vera gel treatment and storage time were not significantly different on aw value and water content value, but the aloe vera gel treatment affect the pH value (p < 0.05). Aloe vera gel treatment and storage time did not affect the number of E. coli, but affect the value of total plate count and positive Salmonella sp. on the control meatballs on the 7th day of storage. It can be concluded that aloe vera gel as an edible coating on meatballs has an effect on the pH value, and improves microbiological quality of meatballs.
Keyword: aloe vera gel, beef meatball, microbiological

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: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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