Judul: Karakteristik Fisik, Organoleptik, dan Fungsional Gel Cincau Hijau Manis (Premna oblongifolia Merr.) Terpasteurisasi.
Abstrak: Green grass jelly (Premna oblongifolia Merr.) can be processed into pasteurized green grass jelly product. The purpose of this study was to determine the type and concentration of sweeteners that could increase physical, organoleptic, and functional characteristics of pasteurized green grass jelly so the product would be more acceptable and have better characteristics. In this study, sucrose, sorbitol, and aspartame were used as sweeteners. The addition of sucrose with concentration of 12% showed the best physical characteristics and organoleptic results. Then, sucrose was replaced by aspartame and sorbitol in order to have low calorie sweetened green grass jelly. Sweetener equivalence organoleptic test was used to determine the sweetness level of the sweeteners that equaled 12% sucrose concentration. Aspartame and sorbitol concentrations that had sweetness level equaled 12% sucrose concentration were 0.05% and 13% respectively. Furthermore, the addition of sorbitol and aspartame did not have any significant impact on the physical and the organoleptic characteristics of the product. However, the functional characteristic analysis showed that sample with 0.05% aspartame concentration had the highest antioxidant capacity of 1.13 mgAEAC/100g and sample with 13% sorbitol concentration had the highest fenol of 156.90 mg GAE/100g. In conclusion the addition of sweeteners to green grass jelly can increase the physical, sensory, and functional characteristics of the product significantly.
Keyword: sensory properties, physical properties sweeteners, green grass jelly, Functional properties

Judul: Gel Cincau Hijau (Premna oblongifolia Merr.) Manis yang Diperkaya dengan Flavor dan Antioksidan Ekstrak Mint, Pala, dan Suji
Abstrak: Green grass jelly is a low-calorie food that contains many bioactive components. In the previous research, green grass jelly with addition of hydrocolloid and NaHCO3 had been made to maintain its physical characteristic after heat treatment. Addition of natural flavor can provide a variety of phytochemicals active components as source of antioxidant. The natural flavor that used in this study were nutmeg and mint. Sucrose (12%) & Suji (5%) were also added as sweetener & to maintain the color of green grass jelly. The purpose of this study was to obtain the best formulation of pasteurized green grass jelly with the addition of nutmeg, mint, and suji extracts. The selected formulation were 10% for mint and 7.5% for nutmeg based on physical analysis at texture, color, pH, and syneresis rate parameter as well as hedonic rating sensory evaluation. Characterization of functional properties showed total chlorophyll content, total phenol, and antioxidant capacity respectively were 0.0284 mg/g w.b, 25.8425 mg GAE/g w.b, and 0.3088 mg AEAC/g w.b for green grass jelly with mint flavor; 0.0311 mg/g w.b, 28.1736 mg GAE/g w.b, and 0.2912 mg AEAC/g w.b for green grass jelly with nutmeg flavor; and 0.0205 mg/g w.b, 17.9144 mg GAE/g w.b, and 0.1306 mg AEAC/g w.b for control (sweet green grass jelly without flavor). In comparison with control, addition natural flavor increased functional properties of green grass jelly in general. Total Plate Count result showed Total Plate Count was <2.5x102 CFU/g, this value in compliance with the requirement of SNI that is <1.0x104 CFU/g.
Keyword: suji, nutmeg, mint, green grass jelly, antioxidant

Judul: Prediksi Kurs Rupiah Terhadap Dollar Amerika Menggunakan Persamaan Schrodinger Nonlinear Diselesaikan dengan Metode Runge Kutta Orde Empat.
Abstrak: Kurs adalah pertukaran antara dua mata uang yang berbeda, yaitu perbandingan nilai atau harga antara kedua mata uang tersebut. Prediksi kurs rupiah dapat dimodelkan dengan persamaan Schrodinger nonlinear yang dihitung dengan metode Runge Kutta orde empat. Parameter yang terdapat dalam persamaan Schrodinger nonlinear dianalogikan ke dalam parameter ekonomi yang diasumsikan sebagai faktor-faktor yang mempengaruhi kurs rupiah. Faktor-faktor tersebut antara lain pergerakan atau pertumbuhan rata-rata kurs rupiah, tingkat inflasi, tingkat suku bunga, kecepatan rata-rata perubahan kurs rupiah, dan Produk Domestik Bruto (PDB). Penelitian ini bertujuan untuk mengetahui nilai prediksi kurs rupiah dari perubahan pergerakan kurs rupiah, sehingga pergerakan kurs rupiah yang fluktuatif akan mempengaruhi nilai prediksinya. Data hasil prediksi nilai kurs rupiah terhadap dolar Amerika dibandingkan dengan data kurs aktual. Hasil prediksi kurs rupiah dari persamaan Schrodinger nonlinear menggunakan metode Runge Kutta orde empat menghasilkan persentase error tertinggi dibawah 5% disetiap bulannya dan menghasilkan nilai Mean Absolute Percentage Error (MAPE) sebesar 0.4786%.
Keyword: kurs rupiah, parameter Schrodinger, Runge Kutta orde empat, Schrodinger nonlinear