Judul: Coating Application of Tapioca and Sago Starch to Extend Shelf Life of Edible Flower  Nasturtium (Tropaelom majus L.)
Abstrak: Bunga nasturtium termasuk edible flower dengan nilai komersil tinggi. Seluruh bagian dari nasturtium aman dikonsumsi dan banyak digunakan sebagai garnish dan bidang farmakologi. Namun, nasturtium memiliki umur simpan yang pendek karena mudah mengalami rusak fisioligis yang disebabkan respirasi dan transpirasi yang tinggi. Pengaplikasian edible coating dapat memperlambat respirasi dan transpirasi yang memperpanjang umur simpan bunga nasturtium. Penelitian ini bertujuan mengkaji pengaruh penggunaan edible coating berbahan tapioka dan pati sagu dengan gliserol terhadap perubahan mutu bunga nasturtium selama masa simpan. Tahapan penelitian terdiri dari persiapan sampel, pembuatan larutan coating, pengujian viskositas, pengaplikasian coating, dan pengamatan selama 7 hari masa simpan. Jenis pati yang digunakan terdiri tapioka dan pati sagu dengan konsentrasi 0,5% dan 1% lalu diberi penambahan gliserol konsentrasi 1% untuk larutan tapioka dan 0,1% untuk larutan pati sagu. Hasil penelitian menunjukkan perlakuan terbaik adalah coating S2G2 (Pati sagu 1% dengan gliserol 0,1%) yang mampu menghambat respirasi, mempertahankan kadar air 92,02%, susut bobot 8,66%, dan nilai ohue 40,47o pada hari ke-7 penyimpanan dengan penerimaan panelis pada skor 3 (dari 0-5) berdasarkan kesegaran, warna, dan aroma hingga hari ke-5. Sementara pada akhir penyimpanan bunga tanpa perlakuan coating (kontrol), susut bobot mencapai 21,16% dengan kadar air 90,90%, nilai ohue 34,70o, dan memiliki skor dibawah penerimaan panelis sejak hari ke-3., Nasturtium flowers are an edible flower with high commercial value. All parts of nasturtium are safe for consumption and used as garnish and pharmacology. However, nasturtium has a short shelf life because it is prone to physiological damage that caused by high respiration and transpiration. The application of edible coating can slow down respiration and transpiration which extends the shelf life of nasturtium flowers. This study aim to examine the effect of using edible coating made from tapioca and sago starch with glycerol on changes in the quality of nasturtium flowers during shelf life. The research stage consists of sample preparation, coating solutions preparation, viscosity test, coating application, and observation for 7 days of shelf life. The type of starch used in coating solution were tapioca and sago starch with a concentration of 0.5% and 1% then adding 1% glycerol for tapioca solution and 0.1% glycerol for sago starch solution. The results showed that the best treatment was S2G2 coating (1% sago starch with 0.1% glycerol) which able to inhibit respiration, maintain 92.02% moisture content, 8.66% weight loss, and 40.47o ohue value on the 7th day of storage with panelists acceptance at a score of 3 (from 0-5) based on freshness, color, and aroma until 5th day. While at the end of storage, flower without coating treatment (control), the weight loss reached 21.16% with a moisture content of 90.90%, 34.70o o hue, and panelist acceptance only 3 days of shelf life.
Keyword: Edible flower, Edible coating, Nasturtium flower, sago starch, Tapioca

Judul: Postharvest Physiology Changes of Nasturtium Flowers (Tropaeolum majus) at Various Storage Temperatures
Abstrak: Bunga nasturtium termasuk sebagai salah satu bunga edible yang semua bagian dari nasturtium aman untuk dikonsumsi. Nasturtium digunakan sebagai hiasan, kuliner, dan bidang farmakologi. Umumnya bunga edible mudah mengalami kerusakan dan memiliki umur simpan yang pendek. Suhu rendah dapat memperpanjang fase umur simpan dengan memperhambat kerusakan fisiologis pada bunga edible khusunya nasturtium. Tujuan penelitian ini adalah mengkaji pengaruh berbagai suhu penyimpanan terhadap perubahan fisiologi pascapanen bunga nasturtium serta menentukan suhu penyimpanan yang baik untuk menjaga mutu dan memperpanjang umur simpannya. Bunga nasturtium di dapat dari supplier bunga edible di Kabupaten Bandung, kemudian di sortir berdasarkan ukuran yang mendekati seragam dan diletakkan dalam wadah thinwall. Penyimpanan bunga nasturtium dilakukan pada 4 perlakuan suhu yaitu 5 °C, 10 °C, 15 °C, dan 20 °C selama 5 hari masa pengamatan. Hasil penelitian menunjukkan bahwa suhu 5 °C dan 10 °C merupakan suhu penyimpanan terbaik karena secara statistik untuk semua parameter yang diukur mulai dari laju respirasi, produksi etilen, kadar air, susut bobot, dan warna secara signifikan tidak berbeda nyata (sig>0,05). Selisih nilai laju respirasi dan kadar air hanya berkisar kurang dari 1 ml.kg-1jam-1 dan 1%. Penerimaan panelis terhadap bunga nasturtium berdasarkan kenampakan pada skor minimum 3 (dari 0 sampai 5) hingga hari ke-3., Nasturtium flowers are included as one of edible flowers that all parts of nasturtiums are safe for consumption. Nasturtium is used as an ornamental, culinary and pharmacological. Generally, edible flowers are easily damaged and have a short shelf-life. Low temperatures can extend the shelf-life phase by inhibiting physiological damage to edible flowers, especially nasturtiums. The purpose of this research was to study the effect of various storage temperatures on changes in postharvest physiology of nasturtium flowers and determine a good storage temperature to maintain quality and extend shelf life. Nasturtium flowers were obtained from an edible flower supplier in Bandung Regency, then sorted based on a size that was close to uniform and placed in thinwall container. Storage of nasturtium flowers was carried out at 4 temperature treatments, namely 5 °C, 10 °C, 15 °C, and 20 °C for 5 days of observation. The results showed that 5 °C and 10 °C were the best storage temperatures because statistically for all parameters measured from respiration rate, ethylene production, moisture content, weight loss, and color were not significantly different (sig>0,05). The difference between respiration rate and water content is only less than 1 ml.kg-1hour-1 and 1%. Panelists' acceptance of nasturtium flowers was based on appearance at a minimum score of 3 (from 0 to 5) until day 3.
Keyword: edible flower, nasturtium flower, physiology, storage temperature

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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