Judul: Analysis of Total Flavonoid Content and Antioxidant Activity  Java Cardamom Fruit with Different Extraction Methods and Durations
Abstrak: Penyebab kematian tertinggi di dunia termasuk Indonesia adalah penyakit degeneratif. Penyakit degeneratif disebabkan oleh radikal bebas yang masuk kedalam tubuh sehingga terjadi stress oksidatif. Buah kapulaga jawa (Amomum compactum) merupakan salah satu rempah yang mengandung metabolit sekunder sebagai sumber antioksidan. Perbedaan metode dan durasi ekstraksi pada buah kapulaga jawa dilakukan untuk mengetahui kadar total flavonoid dan aktivitas antioksidan terbaik. Metode ekstraksi yang digunakan yaitu CSE (Continuous Shaker Extraction), UAE (Ultrasonic Assisted Extraction), dan MAE (Microwave Assisted Extraction). Pengujian aktivitas antioksidan dengan metode DPPH dan FRAP. Metode dan durasi ekstraksi memiliki pengaruh terhadap total flavonoid dan aktivitas antioksidan. Kandungan tertinggi flavonoid didapatkan ekstrak metode CSE dengan durasi 360 menit (3,202 ± 0,337 mg QE g-1 bobot kering) dan aktivitas antioksidan tertinggi dari metode DPPH dan FRAP dihasilkan ekstrak dari metode MAE dengan durasi 3 menit (8,078 ± 0,960 dan 18,637± 4,631 μmol TE g -1 bobot kering). Kandungan total flavonoid dari ketiga metode ekstraksi dengan aktivitas antioksidan metode DPPH berkorelasi positif, kuat, dan signifikan. Kandungan total flavonoid dengan aktivitas antioksidan metode FRAP berkorelasi positif, sedang dan tidak signifikan pada metode CSE dan UAE, sedangkan pada metode MAE berkorelasi positif, kuat, dan signifikan., The highest cause of death globally, including in Indonesia, is caused by non-communicable disease or degenerative disease. Many degenerative disorders occur due to free radicals that enter the body and cause oxidative stress. Java cardamom fruit (Amomum compactum) is one of the spices that can be a source of antioxidants because of the secondary metabolites it produces. The test of java cardamom fruit with different methods and durations of extraction was to determine total flavonoid content and high antioxidant activity. The extraction methods used were Continuous Shaker Extraction (CSE), Ultrasonic Assisted Extraction (UAE), and Microwave Assisted Extraction (MAE). Antioxidant activity was measured by DPPH and FRAP methods. The method and duration of extraction affect the total flavonoid content and antioxidant activity. The highest flavonoid content was found in the extract from the CSE method with a duration which was 360 minutes (3,202 ± 0,337 mg QE g-1 dry weight) and the highest antioxidant activity of the DPPH and FRAP methods was found in the extract from MAE method with a duration which was 3 minutes (8,078 ± 0,960 and 18,637± 4,631 μmol TE g-1 8,078 ± 0,960 and 18,637± 4,631 μmol TE g-1 dry weight). The flavonoid content of the three extraction methods (CSE, MAE, and UAE) with the antioxidant activity of the DPPH method has a positive, strong, and significant correlation. The flavonoid content with the antioxidant activity of the FRAP method was positively, moderately, and significantly correlate with CSE and UAE methods, while the MAE method had a positive, strong, and significant correlation.
Keyword: antioxidant, extraction method, java cardamom fruit, total flavonoid

Judul: Total Phenolics, Flavonoids and Antioxidant Tests Variations in Extraction Methods and Solvents for Java Cardamom Fruit (Amomum compactum Sol. Ex Maton)
Abstrak: Metode dan pelarut ekstraksi dilaporkan mempengaruhi kadar senyawa metabolit sekunder dan aktivitas antioksidan buah kapulaga jawa. Penelitian ini bertujuan menentukan pengaruh metode dan jenis pelarut ekstraksi terbaik filtrat buah kapulaga jawa (Amomum compactum) berdasarkan kadar total fenolik, flavonoid dan aktivitas antioksidan. Buah kapulaga jawa diekstraksi dengan metode konvesional Refluks dan metode modern yaitu Microwave Assisted Extraction (MAE) dan Continuous Shaking Extraction (CSE) dengan pelarut Etanol, Metanol, dan Akuades. Hasil penelitian menunjukkan metode ekstraksi MAE pelarut Akuades memperoleh hasil tertinggi pada kadar fenolik yaitu 1,33, Extraction methods and solvents were reported to influence the levels of secondary metabolite compounds and antioxidant activity of Javanese cardamom fruit. This study aimed to determine the effect of the best extraction method and type of solvent for Javanese cardamom (Amomum compactum) fruit filtrate based on total phenolic, flavonoid and antioxidant activity levels. Javanese cardamom fruit is extracted using the conventional Reflux method and modern methods, namely Microwave Assisted Extraction (MAE) and Continuous Shaking Extraction (CSE) with the solvents Ethanol, Methanol, and Aquades. The results showed that the MAE extraction method using Aquades solvent obtained the highest results in phenolic content, namely 1.33
Keyword: antioxidant, cardamom, methods, secondary metabolites, solvents

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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