Judul: Carrageenan and Chitosan Application as an  Edible Coating to Extend Shelf Life Carnation (Dianthus caryophyllus L.)
Abstrak: In recent years, interest in edible flowers has increased. The problem that arises with edible flowers is that this commodity is perishable quickly, cannot be stored for long, and is required to be fresh. One alternative technology that can be done to increase the shelf life of carnations is to use carrageenan and chitosan edible coating applications. The purpose of this research was to examine the effect of using edible coatings of carrageenan and chitosan on changes in the quality of carnation flowers and to determine the best coating solution treatment based on the shelf life of the carnations produced. The results showed that the best treatment was coating with 0.1% chitosan solution (Q1) which was able to maintain the water content, weight loss, and hue values of 79.61%, 7.93%, and 26.62° to 6 shelf life with panelists' acceptance on score of 3 (from 0-5) based on color and freshness. Meanwhile, flowers without coating treatment (control) had moisture content, weight loss, and hue values of 74.01%, 11.68%, and 24.13°. However, these results may need to be reviewed with the same experiments in near future because the chitosan material used is categorized as technical material whose quality is unknown. The material used for coating should refer to Badan Standarisasi Nasional (BSN).
Keyword: Carnation, coating, carrageenan, chitosan, shelf life

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: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix