Judul: High Fiber Powder Drink Formulation based on Sargassum sp., Ipomoea batatas, and Seaweed Salt
Abstrak: Rumput laut Sargassum sp., ubi ungu dan jahe merah sudah dikombinasikan menjadi produk minuman serbuk tinggi serat. Formulasi yang digunakan masih dapat dikembangkan dan belum diuji nilai fungsionalnya. Penelitian ini bertujuan menentukan formulasi terbaik serta menganalisis pengaruh penambahan garam rumput laut terhadap serat pangan, mineral, aktivitas air, abu tidak larut asam, logam berat, dan aktivitas antioksidan. Tahapan penelitian ini yaitu pembuatan serbuk, penentuan formulasi terbaik, dan uji lanjutan. Perbedaan formula bahan baku berpengaruh terhadap warna, aroma, rasa, aftertaste, dan proksimat. Hasil uji serat pangan F1 dan F4 sebagai formulasi terbaik yaitu serat larut air 5,06–5,14%, serta serat tidak larut air 20,09–22,62%. Mineral yang terkandung yaitu kalsium 6,53–7,35 mg/g, kalium 7,41–9,075 mg/g, magnesium 3,16–3,28 mg/g, natrium 1,95–6,32 mg/g, dan besi 0,07 mg/g. Aktivitas air produk sebesar 0,29 dan abu tidak larut asam 0,15–0,20%. Senyawa fitokimia yang terkandung yaitu alkaloid, flavonoid, triterpenoid, fenol, tanin dan glikosida. Nilai aktivitas antioksidannya sebesar 86,708 μmol troloks/g (F1) dan 87,499 μmol troloks/g (F4)., Sargassum sp., purple sweet potato and red ginger have been combined into a high-fiber powder drink product. Existing formulation can still be developed and the functional value has not been tested. This research was aimed to determine the best formulation of powdered drink and analyze the effect of adding seaweed salt to dietary fiber, minerals, water activity, acid insoluble ash, heavy metals, and antioxidant activity. The phases of this research were making powder, determining the best formulation, and further testing. Differences in the formula of raw materials affect the color, aroma, taste, aftertaste, and proximate. The results of the F1 and F4 dietary fiber test as the best formulations were soluble fiber 5.06–5.14%, and insoluble fiber 20.09–22.62%. The minerals contained were calcium 6.53–7.35 mg/g, potassium 7.41–9.075 mg/g, magnesium 3.16–3.28 mg/g, sodium 1.95–6.32 mg/g, and 0.07 mg/g iron. The water activity of the product was 0.29 and the acid insoluble ash was 0.15–0.20%. Phytochemical compounds contained in the product were alkaloids, flavonoids, triterpenoids, phenols, tannins, and glycosides. The antioxidant activity values were 86,708 μmol trolox/g (F1) and 87,499 μmol trolox/g (F4).
Keyword: antioksidan, jahe merah, karbohidrat, mineral, serat pangan

Judul: Kajian rumput laut sebagai sumber serat alternatif untuk minuman berserat
Abstrak: AZRINA CHAIDIR. Study on Seaweed as Alternative Dietary Fiber for Health Drink. Under the direction of USMAN AHMAD and SANTOSO Seaweed is one of marine commodities with high potential as dietary fiber source. The composition, dietary fiber and some physico-chemical properties of two red seaweeds powder (made from Eucheuma cottonii and Glacilaria sp) and one brown seaweed powder (made from Sargassum sp) was investigated using different blanching method and drying temperature. The methods of blanching are fresh water about 9 hours, rice powder solution with 5 % konsentration about 9 hours and combination fresh water and 0,5 % CaO solution. The oven temperature that used for drying seaweeds was 50 and 70 oC. The best blanching method for Eucheuma cottonii and Sargassum sp are fresh water about 9 hours, and for Glacilaria sp is combination fresh water and 0,5 % CaO solution. The best temperature for drying seaweeds are 70 oC. The seaweed powders have good appearance, smell and texture. Eucheuma cottonii powder has 72,19 % soluble dietary fiber, 11,23% insoluble dietary fiber out of 83,42% total dietary fiber. Glacilaria sp has 62,95% soluble dietary fiber, 20,67% insoluble dietary fiber out of 83,62% total dietary fiber. Meanwhile, Sargassum sp has 24,99% soluble dietary fiber, 57,62% insoluble dietay fiber out of 82,61% total dietary fiber. The health drink with Eucheuma cottonii and a combination of E. cottonii and Glacilaria sp powders as fiber source were accepted by panelis although less favourable in flavor and taste compared with commercial health drink.
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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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