Judul: Formulation of Black Mulberry Ice Cream (Morus nigra sp.) as a High Potassium Alternative Foods
Abstrak: Asupan kalium dapat berkontribusi terhadap penurunan tekanan darah melalui keseimbangan cairan dan elektrolit. Kalium merupakan kandungan mineral utama dalam buah dan daun murbei hitam. Buah dan daun murbei hitam dapat dikembangkan menjadi es krim sebagai produk pangan alternatif tinggi kalium. Penelitian ini bertujuan untuk mengembangkan dan mengkaji nilai gizi produk es krim dengan penambahan buah dan daun murbei hitam. Tahap penelitian ini meliputi pembuatan formula, uji sensori, analisis kandungan gizi dan analisis karakteristik fisik. Penelitian ini menggunakan tiga formula dengan rasio buah dan daun murbei yang berbeda, yaitu F1 (17:0), F2 (16:1), F3 (15:2). Berdasarkan hasil uji sensori, analisis kandungan gizi dan karakteristik fisik, F1 ditetapkan sebagai formula terpilih dengan kandungan 57,92% air; 1,84% abu; 7,52% protein; 6,07% lemak; 32,73% karbohidrat; 1229,31 mg kalium/100 g produk; dan 347,23 mg kalsium/100 g produk. Satu takaran saji es krim murbei hitam dalam penelitian ini dapat memenuhi kebutuhan energi sebesar 214 kkal serta dapat memenuhi klaim tinggi kalium, tinggi kalsium dan sumber protein., Potassium intake can contribute to lower blood pressure through balancing the body fluid and electrolyte fluid. Potassium is the main mineral content in black mulberry fruit and leaves. This berries might also be developed into ice cream as an alternative high-potassium consumable product that is favored by all ages. This study aimed to develop and assess the nutritional values of ice cream products with the addition of black mulberry berries and leaves. This research includes the formula development, sensory evaluation, nutrient analysis and physical analysis. This study used three formulas with different ratios of mulberry fruit and leaf, i.e F1 (17:0), F2 (16:1), F3 (15:2). Based on the results of sensory tests, analysis of nutritional contents and physical characteristics, F1 was determined as the selected formula with 57.92% water; 1.84% ash; 7.52% protein; 6.07% fat; 32.73% carbohydrates; 1229.31 mg Potassium/100 g product; and 347.23mg of Calcium/100 g product. One serving of black mulberry ice cream in this study can meet 214 kkal of daily energy intake. One serving of black mulberry ice cream also can meet the claims of high potassium, high calcium and protein sources.
Keyword: black mulberry fruit, black mulberry leaves, ice cream, potassium

Judul: The Substitution of Peel Puree to Dragon Fruit Ice Cream Improves Physical and Organoleptic Quality with Identical Calcium Bioavailability
Abstrak: Kalsium merupakan mineral makro yang memiliki peran penting dalam fungsionalitas tubuh. Kalsium yang diserap tubuh digambarkan oleh bioavailabilitas kalsium. Bioavailabilitas kalsium dapat dipengaruhi oleh zat anti-gizi yang dapat ditemukan dalam buah. Penelitian ini bertujuan mengkaji substitusi pure kulit buah naga dalam es krim buah naga merah. Desain penelitian ini adalah eksperimen dengan rancangan acak lengkap (RAL). Tahap penelitian terdiri dari formulasi, pembuatan produk, uji karakteristik fisik, organoleptik, proksimat, penentuan formula terpilih, analisis kandungan dan bioavailabilitas secara in vitro serta analisis kontribusi dan klaim gizi. Formula terpilih adalah F2 dengan rasio pure daging dan kulit buah naga merah 60:40. Es krim terpilih memiliki kadar air 63,6%; kadar abu 3,4%; lemak 12,0%; protein 13,0%; dan karbohidrat 8,1% dengan kontribusi energi 8,9% berdasarkan acuan label gizi (ALG). Kandungan kalsium es krim 264,90 mg/100 g dengan bioavailabilitas 70,55%. Kandungan dan bioavailabilitas es krim tidak berbeda antara es krim kontrol dan terpilih berdasarkan independent samples t-test (p>0,05). Es krim dapat diklaim sebagai makanan sumber kalsium dengan kontribusi sebesar 24,1%., Calcium is a macro mineral that has important roles in body functionality. Calcium absorbed by the body is described by the bioavailability of calcium. The bioavailability of calcium can be affected by anti-nutrients sometimes found in fruit. This study aims to examine dragon fruit peel puree substitution in red dragon fruit ice cream. The research design is an experiment with a completely randomized design (CRD). The research stages are formulation, product manufacture, physical characteristic, organoleptic, and proximate analysis, formula selection, analysis of calcium content and bioavailability in vitro as well as analysis of contribution and nutritional claims. The selected formula is F2 with a red dragon fruit pulp and peel puree ratio of 60:40. Ice cream has a moisture of 63.6%, ash 3.4%, fat 12.0%, protein 13.0%; and carbohydrates 8.1% with energy contribution 8.9% based on nutrition label reference. The calcium of ice cream is 264.90 mg/100 g with a bioavailability of 70.55%. The content and bioavailability of ice cream are identical between control and selected ice cream based on independent samples t-test (p>0.05). Ice cream can be claimed as a source of calcium with a contribution of 24.1%.
Keyword: calcium bioavailability, ice cream, red dragon fruit’s peel puree

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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