Judul: Analisis oligosakarida hasil hidrolisis pati kentang hitam (Culeus tuberosus) oleh Enzim amilase dari Brevibacterium sp.
Abstrak: Oligosaccharide is an important group of carbohydrate macromolecul composed of 2 to 20 saccharide units. Oligosaccharide has many benefits in the field of food and health. Starch is one of the source origin material for oligosaccharide production by enzimatic process. Black potatoes contain high carbohydrates especially starch of about 83%. To obtain oligosaccharide from black potato starch can be hidrolyzed using amylase enzymes which are produced by Brevibacterium sp. Crude extracts amylase enzyme production from Brevibacterium sp. producing enzyme activity of 3.25 U/mL. Black potato starch hydrolysis results a value of reducing sugar of 7482.500 ppm, after freeze drying a value of reducing sugar was 9647.500 ppm, and after concentrated by vacuum evaporator the value of reducing sugar was 14908.300 ppm. The results of HPLC analysis of black potato starch hydrolysis showed that there are oligosaccharide compound such as maltose, maltotriose, and maltopentose. The samples were given preferential treatment freeze dry and evaporation produce reducing sugar value and concentration of the oligosaccharide better than the fresh samples without treatment. The identification result of oligosaccharide obtained by HPLC shows that freeze drying and evaporating samples has a higher concentration and better peak and sharp.
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Judul: Produksi Oligosakarida dari Umbi Kentang Hitam melalui Hidrolisis Ekstrak Kasar α-Amilase asal Brevibacterium sp.
Abstrak: Oligosaccharides is a carbohydrate macromolecule composed of 2-10 monosaccharide residues that have benefits in the field of food and health. One way to produce oligosaccharides with enzymatic hydrolisis of starch. Black potatoes have high carbohydrate content, especially starch by 83%. Activity of amylase enzyme from raw extraction have 1.708 U/ml. Degree of polymerization of black potatoe’s starch is 10. Hydrolysis reaction of black potatoe’s starch with that enzyme gave 3 spots on TLC analysis with mobile phase n-buthanol:acetic acid:water purified (2:1:1). In HPLC analysis showed 3 main peaks that means consist of 3 compound with mobile phase acetonitrile:water (75:25). Fresh sample consist of glucose as many as 1,60% (b/v), maltose 0,36% (b/v), and maltotriose 0,46% (b/v). Freeze dried sample consist of glucose as many as 4,20% (b/v), maltose 0,21% (b/v), and maltotriose 0,30 % (b/v).
Keyword: Brevibacterium sp., α-amylase enzyme, HPLC, oligosaccharides, black potatoes

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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