Judul: Optimasi kapasitas antioksidan dan penerimaan sensori pada minuman fungsional jahe merah (Zingiber Officinale. Rosc) dengan penambahan rempah-rempah
Abstrak: Minuman fungsional mempunyai manfaat positif bagi kesehatan. Minuman berbasis jahe banyak dikonsumsi karena rasa menyenangkan dan efek trigeminal yang bisa memberikan efek hangat bagi tubuh. Penelitian tentang minuman jahe merah dikombinasikan dengan pandan dan sereh telah dilaporkan, tetapi penerimaan konsumen terhadap minuman ini dari segi cita rasa masih rendah. Kombinasi dengan rempah lain, yaitu kunyit dan daun pandan, dilakukan pada penelitian ini untuk meningkatkan penerimaan. Response Surface Methodology (RSM) digunakan untuk mengoptimalkan formulasi dan menganalisis pengaruh konsentrasi jahe merah, kunyit dan daun pandan terhadap karakteristik sensori dan kapasitas antioksidan. Karakteristik sensori meliputi atribut aroma, rasa dan overall. Optimasi formula minuman fungsional jahe merah-pandan-kunyit menggunakan disain campuran menghasilkan formula yang optimum yaitu kombinasi jahe merah sebesar 2.65%(w/v), kunyit 1.45%(w/v), dan pandan sebesar 3.90%(w/v). Formula optimum dapat meningkatkan atribut sensori minuman fungsional dibandingkan formula penelitian terdahulu dan produk komersial. Formula optimasi memiliki kapasitas antioksidan sebesar 0.17 mgAEq/ml sedangkan sebelumnya 0.16 mgAEq/ml. Nilai uji rating hedonik dari formula optimasi adalah 6.4 (suka) untuk aroma, 5.9 (mendekati suka) untuk rasa, dan 6.1 (suka) untuk keseluruhan, sedangkan formula sebelumnya adalah 5.5 (agak suka) untuk aroma, 5.2 (agak suka) untuk rasa dan 5.6 (agak suka) untuk keseluruhan. Formula optimasi memiliki kapasitas antioksidan sebesar 0.17 mgAEq/ml sedangkan sebelumnya 0.16 mgAEq/ml.
Keyword: Red Ginger, Turmeric, Pandan, Functional Drink, Response Surface Methodology (RSM)

Judul: Optimasi Formula Minuman Fungsional Berbasis Kunyit (Curcuma domestica Val.), Asam Jawa (Tamarindus indica Linn.), dan Jahe (Zingiber officinale var. Amarum) dengan Metode Desain Campuran (Mixture Design).
Abstrak: Turmeric, tamarind, and ginger have been widely used as Indonesian traditional beverage called “jamu”. “Jamu” is known for its functional characteristics, such as high antioxidant capacity. This beneficial factor makes “jamu” potential to be developed as a functional beverage. This study showed the optimization of functional beverage formula based on turmeric, tamarind, and ginger. The objective of this study is to discover an optimum functional beverage formula with high antioxidant capacity and good sensory qualities (colour, aroma, taste, and overall). The method used in the optimization of the formula was mixture design method. Design Expert (DX) 7.0® software was used as a tool in the optimization. The result reveals the optimum formula is a mixture with 5.0%(v/v) turmeric extract, 9.9%(v/v) tamarind extract, 15.1%(v/v) ginger extract, 40%(v/v) sugar solution, and 30%(v/v) water. The formula had antioxidant capacity of 0.1741mgAEq/ml. The sensory scores obtained for the formula are 4.40 for colour, 4.20 for aroma, 4.10 for taste, and 4.27 for overall (scale 1-7). The colour of the formula is yellow with ˚Hue of 68.5922˚ (L=47.0433, a=13.4500, b=34.3067). The formula has pH value of 3.60 and total soluted solid value of 14.90˚Brix.
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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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