Judul: Pengembangan Minuman Fungsional Sumber Serat Dan Antioksidan Dari Daun Hantap (Sterculia oblongata R. Brown.)
Abstrak: Sterculia oblongata R. Brown or in Sundanese known as Hantap has been used as expectorant, sore throat, stomachache, and constipation medicine. The health benefit of those was related to its phytochemical content, chlorophyll and dietary fiber. Due to limited information to hantap research, this research become important. The main goal of this research was to study the production of hantap’s leaves drink as antioxidant and dietary fiber source. Antioxidant activity (AA) and dietary fiber content (DFC) were analysed by DPPH and Enzymatic methode. Leaves contained alkaloid, sapoin, tanin, flavonoid, triterpenoid, steroid and glicoside. Leaves’s AA correlated positively to total phenol content (TPC) (r=0,9914). The leaves had AA about 42,75-47,66% (133,46 mg vitamin C/100 gram) (wb), TPC about 919,47 mg Galic Acid Equivalen (GAE) (db) or 326,16 (wb) GAE and 54,76 mg vitamin C (db) or 19,43 mg vitamin C (wb). The leaves contained chlorophyll about 5245,81 μg/gram and could be the source of dietary fiber with soluble (SDF) and insoluble fiber (IDF) content 4,5% dan 15,67% respectively. The Hantap’s Leave Functional Drink (HLFD) formula was produced by extracting the leaves with leaves-water ratio 1:15. The extraction used two methode namely hand squezzing (R) and blender (B) machine. Then the leaves extract mixed with water melon essens about 0,4% and sugar about 15%. General acceptancy level of the HLFD was respectively 72,41% and 86,20% for B and R. HLFD characteristics were moderate acid (6,00-6,26), moderate viscous (300-450 Cp) and have total solid dissolved (TDS) that supposed as soluble dietary fiber (13,25-13,5 0Brix). AA of R about 50,87%-64,61% (3,92-4,99 AEAC). Adversly, B antioxidant activity was about 38,69%-44,44% (2,95-3,39 AEAC). Chlorophyl content of HLFD was 800,49 μg/gram and 1194,06 μg/gram respectively for R and B. Soluble fiber content of B was higher than R respectively 0,353% (wb) dan 0,134% (wb). Adversly insoluble fiber content for R was higher than B respectively 0,310% (wb) and 0,243% (wb).
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Judul: Pengembangan Produk Minuman Jeli Ekstrak Daun Hantap (Sterculia oblongata R. Brown) sebagai Alternatif Pangan Fungsional
Abstrak: The objective of this study was to develop a jelly drink product based on hantap leaves extract as an alternative of functional food. Completed Randomize Nested Design with two factor (The type and level of concentration of the gelling agent) was applied in this study and resulted in nine formulas. The selected jelly drink formula was determined by preference test using semitrained panelists. Jelly drink with the addition of a gelling agent carrageenan with a concentration level of 0.20% and melon flavor was preferred by 86% panelist. This formula contained 87.37% water ,0.18% ash, 0.10% protein, 0 .04% fat, 12.3% carbohidrate, 2.08% fiber, 10.6 mg/100g total phenols, 0.68 mg/100g vitamin C and antioxidant activity 20.92 % with IC50 values is 464.02μL. With its bioactive component and fiber content, this product may be classified as functional food which may help improving consumer health.
Keyword: jelly drink., hantap leaves, functional food, fiber, antioxidants

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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