Judul: Fermentation of Spirulina plantensis by Lactobacillus plantarum SK(5) and its Fortification on Probiotic Ice Cream
Abstrak: Spirulina dapat berperan sebagai prebiotik bagi bakteri bakteri asam laktat probiotik. Lactobacillus plantarum SK(5) merupakan bakteri asam laktat asal bekasam yang bersifat sebagai probiotik. Penelitian ini bertujuan menentukan karakteristik spirulina fermentasi dan pengaruh perbedaan konsentrasi spirulina fermentasi terhadap karakteristik es krim spirulina probiotik. Spirulina platensis diperoleh melalui kultivasi mandiri selama 13 hari dengan nilai optical density (OD) sebesar 0,54. Biomassa spirulina difermentasi menggunakan Lactobacillus plantarum SK(5) pada suhu 37℃ selama 48 jam. Karakteristik spirulina fermentasi yang dihasilkan yaitu pH 3,38, total asam tertitrasi 0,7% dan total bakteri asam laktat 8,15 log cfu/mL. Spirulina fermentasi selanjutnya difortifikasi ke dalam es krim dengan formula E0 (tanpa penambahan spirulina fermentasi), E10 (10 g), E15 (15 g), dan E20 (20 g). Data yang dianalisis pada es krim probiotik meliputi overrun, total padatan, daya leleh, komposisi kimia (protein, lemak, air, abu, dan karbohidrat), total BAL, kadar TAT dan nilai pH. Es krim spirulina probiotik memiliki overrun 19,25-20,42%, total padatan 40,55-42,37%, daya leleh 1,41- 1,53%, kadar protein 6,23-7,33%, kadar lemak 3,49-3,37%, kadar air 57,63- 59,46%, kadar abu 1,70-1,85%, karbohidrat 28,67-29,72%, nilai pH 6,22-6,27, total asam tertitrasi 0,52-0,68%, dan total bakteri asam laktat 0,00-6,59 log cfu/mL. Es krim yang difortifikasi dengan spirulina fermentasi dapat dinyatakan sebagai produk probiotik. Perlakuan terbaik yaitu formula es krim E20 (fortifikasi spirulina sebanyak 20 g), mempunyai karakteristik total padatan 41,79%, kadar protein 7,33%, total BAL 6,59 log cfu/mL (106 cfu/mL) kadar TAT 0,86% dan nilai pH 6,22., Spirulina can act as a prebiotic for probiotic lactic acid bacteria. Lactobacillus plantarum SK(5) is a lactic acid bacteria from fermented fish product which acts as a probiotic. This study aims to determine the characteristics of fermented spirulina and the effect of different concentrations of fermented spirulina on the characteristics of probiotic spirulina ice cream. Spirulina platensis was obtained through self-cultivation for 13 days with an optical density (OD) value of 0,54. Spirulina biomass was fermented using Lactobacillus plantarum SK(5) at 37℃ for 48 hours. The characteristics of fermented spirulina produced were pH 3,38, total titrated acid 0,7% and total lactic acid bacteria 8,15 log cfu/mL. The fermented spirulina was then fortified into ice cream with the formula E0 (without the addition of fermented spirulina), E10 (10 g), E15 (15 g), and E20 (20 g). Characterization of probiotic ice cream included overrun, total solids, melting power, chemical composition (protein, fat, water, ash, and carbohydrates), total LAB, TAT content and pH values. Characteristics of probiotic spirulina ice cream were overrun of 19,25-20.42%, total solids 40,55-42,37%, melting power 1,41- 1,53%, protein content 6,23-7,33%, fat content 3,49-3,37%, water content 57,63- 59,46%, ash content 1,70-1,85%, carbohydrates 28,67-29,72%, pH value 6,22-6,27, total titrated acid was 0,52-0,68%, and total lactic acid bacteria was 0,00-6,59 log cfu/mL. Ice cream fortified with fermented spirulina can be declared as a probiotic product. The best treatment was ice cream formula E20 (it fortified with fermented spirulina of 20 g), which had the characteristics of total solids 41,79%, protein content 7,33%, total LAB 6.59 log fcu/mL (106 cfu/mL), TAT content 0,86% and pH value 6,22.
Keyword: Spirulina, Es krim, Fermentasi, Lactobacillus plantarum SK(5), Bakteri asam laktat, Ice cream, Probiotik, Probiotic, Lactic acid bacteria, Fermentation, Fermented spirulina, Spirulina fermentasi

Judul: Lactobacillus plantarum SK (5) Asal Bekasam sebagai Starter dalam Fermentasi Susu yang Diaplikasikan pada Es Krim Spirulina
Abstrak: Susu fermentasi dengan starter Lactobacillus plantarum SK (5) dapat dibuat menjadi produk seperti es krim. Penelitian ini bertujuan menentukan karakteristik susu fermentasi dengan penambahan starter L. plantarum SK (5) asal bekasam dan menentukan pengaruh penambahan susu fermentasi terhadap nilai pH, total bakteri asam laktat, serta karakteristik es krim spirulina. Formula es krim Spirulina dilakukan dengan subtitusi 25%, 50%, 75%, dan 100% susu fermentasi terhadap susu pasteurisasi non lemak. Karakteristik susu fermentasi yang dihasilkan yaitu pH 5.49, TAT 0.3%, dan BAL 1.73×109 m s krim pirulina yang dihasilkan memiliki p berkisar berkisar 8.6 (Log CFU/mL), overrun total padatan daya leleh menit anelis memilih es krim pirulina formula subtitusi susu fermentasi terhadap susu pasteurisasi non lemak). Formula terbaik berdasarkan analisis kimia, fisik, dan uji hedonik yaitu F50 (subtitusi 50% susu fermentasi terhadap susu pasteurisasi non lemak).
Keyword: es krim, Lactobacillus plantarum, susu fermentasi

Judul: Real Option Valuation Using Binomial Decision Trees.
Abstrak: A firm that decides to invest has a choice to invest in real assets. A method which is usually used in valuation of the project is discounted cash flow (DCF) method. But, this method can’t be used in projects that account for value of managerial flexibility, such as decision to suspend operations temporarily. Therefore, this kind of project needs to be assessed using real option. Real option valuation can be done in some ways, including the use of path-dependent simulation, as well as closed-form models like Black-Scholes model, partial differential equation, and binomial or multinomial approaches. In this paper, real option valuation using binomial decisions id discussed. Determination of the project value can be done in three steps. First, calculate the expected present value of the project. Next, calculate volatility of the project using Monte Carlo simulation. Last, construct a binomial tree to model the dynamics of the project value using the parameters of the stochastic process, and then add some decision nodes to model the project’s real options.
Keyword: