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: Coating Application of Corn Starch and Red Galangal to Extend the Shelf Life of (Chrysanthemum morifolium)
Abstrak: Krisan (Chrysanthemum morifolium) memiliki nilai ekonomis yang tinggi. Namun, krisan segar mudah rusak dan umur simpannya pendek. Respirasi yang tinggi dan mikroorganisme merupakan penyebab utama penurunan kualitas bunga krisan setelah panen. Mikroorganisme berupa jamur Puccinia horiana penyebab penyakit karat putih pada daun akan terbawa pada saat bunga dipanen dan disimpan untuk distribusi. Pati jagung sebagai bahan edible coating yang dikombinasikan dengan ekstrak lengkuas merah yang mengandung fenol diharapkan mampu menahan laju respirasi dan menghambat perkembangan mikroorganisme. Penelitian ini bertujuan untuk menganalisis pengaruh penggunaan edible coating berbahan pati jagung dan lengkuas merah terhadap kualitas bunga krisan selama umur simpan serta menentukan konsentrasi pati jagung dan ekstrak lengkuas merah yang terbaik. Konsentrasi yang dipilih untuk membuat larutan coating berdasarkan diameter dan kerapatan droplet serta viskositas larutan. Konsentrasi larutan coating pati jagung 2% terpilih menjadi konsentrasi larutan terbaik untuk coating. Pada proses pengaplikasian, kombinasi larutan coating yang digunakan adalah pati jagung 2% dan ekstrak lengkuas merah 1% dan 2% serta jumlah semprotan sebanyak 1 kali dan 2 kali semprot. Hasil penelitian menunjukkan bahwa formulasi L2S2 merupakan perlakuan terbaik yang mampu mempertahankan kadar air pada 86,02%, susut bobot 19,00%, nilai L 34,50o, nilai ohue 347,04o pada hari ke-7 penyimpanan dengan penilaian panelis pada skor 3,25 (dari 0-5) berdasarkan kesegaran, warna, dan aroma serta hasil analisa total plate count (TPC) sebesar 6,67 x 103 cfu/ml dengan ambang batas Standar Nasional Indonesia (SNI) yaitu 103 cfu/ml dibandingkan dengan perlakuan tanpa coating (kontrol) yang bertahan selama 3 hari., Chrysanthemum (Chrysanthemum morifolium) has high economic value. However, fresh chrysanthemums are perishable and have a short shelf life. High respiration and microorganisms are the main causes of the decline in the quality of chrysanthemums after harvest. Microorganisms in the form of the fungus Puccinia horiana that causes white rust disease on leaves will be brought in when the flowers are harvested and stored for distribution. Corn starch as an edible coating material combined with red galangal extract containing phenol is expected to be able to restrain the rate of respiration and inhibit the development of microorganisms. This study aims to analyze the effect of using edible coating made from corn starch and red galangal on the quality of chrysanthemum flowers during shelf life and to determine the best concentration of corn starch and red galangal extract. the concentration chosen to make the coating solutions are based on the diameter and density of the droplet as well as the viscosity of the solution. The concentration of 2% corn starch coating solution was chosen to be the best solution concentration for coating. In the application process, the combination of coating solution used was 2% corn starch and 1% and 2% red galangal extract and the number of sprays was 1 and 2 times. The results showed that the L2S2 formulation was the best treatment which was able to maintain water content at 86.02%, weight loss at 19.00%, L value at 34.50o, ohue value at 347.04o on the 7th day of storage with panelist assessment at a score of 3.25 (from 0-5) based on freshness, color, and aroma as well as the results of
Keyword: bunga krisan, edible flower, edible coating, pati jagung, lengkuas merah

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
Keyword: