Judul: Eco-enzyme Fermentation Characters of Pineapple and Lemon Peels
Abstrak: Setiap tahun sampah di Indonesia semakin meningkat, seiring dengan bertambahnya jumlah penduduk, khususnya sampah organik berupa sisa makanan. Kesadaran masyarakat dalam melakukan pengolahan sampah cukup rendah, menyebabkan sampah akan menumpuk di tempat pembuangan akhir (TPA), dan menimbulkan masalah lingkungan. Sampah perlu didaur ulang untuk mengurangi penumpukan sampah. Salah satu contohnya dengan membuat eco-enzyme. Eco-Enzyme adalah larutan zat organik kompleks yang dihasilkan dari proses fermentasi, dibuat dari sisa bahan organik berupa kulit buah dicampurkan molase dan air di dalam botol kaca dengan perbandingan 3:1:10, disimpan dalam suhu ruang selama 3 bulan. Penelitian ini bertujuan untuk mengetahui perbandingan karakter fermentasi eco-enzyme menggunakan kulit nanas (Ananas comosus) dan kulit lemon (Citrus limon). Fermentasi diamati dengan mengukur penurunan pH, total gula, dan total plate count(TPC). Hasil penelitian menunjukkan nilai pH eco-enzyme mengalami penurunan selama proses fermentasi. Tingkat keasaman eco-enzyme rendah disebabkan banyak asam organik dihasilkan dari proses fermentasi. Gula reduksi mengalami peningkatan seiring fermentasi, menunjukkan karbohidrat kompleks pada telah dipecah dengan adanya enzim pada eco-enzyme. Jumlah mikroorganisme pada kedua produk eco-enzyme tidak berbeda nyata, terdapat sedikit koloni bakteri pada media CMC dan TSB. Peningkatan asam organik menyebabkan penurunan pertumbuhan mikroorganisme dan kadar gula reduksi dalam eco-enzyme., Every year, waste in Indonesia is increasing, in line with increasing population, especially organic waste in the form of food scraps. Public awareness in conducting waste management is low, causing waste to accumulate in landfills and environmental problems. Garbage needs to be recycled, by making eco-enzymes. Eco-Enzyme is a solution of complex organic substances, made from leftover organic matter mixed with molasses and water in a glass bottle with a ratio of 3:1:10, stored at room temperature for 3 months. This study aims to determine the comparison of eco-enzyme fermentation characters using pineapple peels (Ananas comosus) and lemon peels (Citrus limon). Fermentation was observed by measuring the decrease in pH, total sugar, and total plate count. The results showed that pH value of the eco-enzyme decreased during fermentation process. Eco-enzyme acidity level is low because a lot of organic acids are produced from fermentation process. Reducing sugar increases with fermentation, indicating that complex carbohydrates have been broken down in the presence of enzymes in eco-enzymes. The number of microorganisms was not significantly different, there were few bacterial colonies on the CMC and TSB media. The increase in organic acids causes a decrease in the growth of microorganisms and reduces sugar.
Keyword: Ecoenzyme, Fermentation, lemon peel, Pineapple peel

Judul: Analisis Karakteristik Kimia, Biologi dan Organoleptik Eco-enzyme Berbahan Baku Kulit: Nanas, Melon, Pepaya dan Pisang
Abstrak: Eco-enzyme merupakan larutan hasil fermentasi limbah organik. Dalam pembuatan eco-enzyme digunakan gula, limbah organik seperti kulit buah atau sayur, dan air dengan perbandingan masing-masing 1:3:10. Eco-enzyme dapat dimanfaatkan sebagai pupuk, pestisida, cairan pembersih rumah tangga, serta dapat digunakan untuk mengurangi pencemaran air dan udara. Penelitian ini bertujuan mengetahui karakteristik kimia, biologi dan organoleptik eco-enzyme berbahan baku kulit: nanas, melon, pepaya dan pisang pada jenis gula yang berbeda serta mengetahui potensi eco-enzyme sebagai pupuk organik cair. Hasil analisis kimia menunjukkan bahwa eco-enzyme memiliki pH di bawah 4,00 serta eco-enzyme mengandung N, P, K, dan C-Organik yang masih dibawah standar mutu pupuk organik cair. Eco-enzyme kulit pepaya memiliki kandungan N-Total dan P tertinggi dibanding perlakuan kulit buah lainnya. Eco-enzyme kulit pisang memiliki kandungan K dan C-Organik tertinggi dibanding perlakuan kulit buah lainnya. Kandungan N, P, K dan C-Organik perlakuan gula merah lebih tinggi dibanding perlakuan gula pasir. Hasil analisis karakteristik biologi eco-enzyme menunjukkan bahwa total mikrob dan fungi perlakuan gula merah lebih tinggi dibanding perlakuan gula pasir. Hasil uji organoleptik menunjukkan bahwa eco-enzyme memiliki aroma asam khas fermentasi dan memiliki warna kuning-kecoklatan hingga coklat., Eco-enzyme is a solution of organic waste fermentation. Eco-enzyme produced by sugar, organic waste such as fruit peels or vegetables, and water in a ratio of 1:3:10. Eco-enzymes can be used as fertilizer, natural pesticides, household cleaners, and can be used to reduce water and air pollution. This study aims to determine the chemical, biological, and organoleptic characteristics of eco-enzymes made from peels of: pineapple, melon, papaya and banana on different types of sugar and to determine the potential of eco-enzymes as an organic liquid fertilizer. The chemical analysis results showed that the eco-enzyme has a pH below 4.00 and the content of N, P, K and organic carbon in eco-enzyme are below the range of values in the quality standards of liquid organic fertilizer. Eco-enzyme from papaya peel has the highest N and P content compared to other fruit skin treatments. Eco-enzyme from banana peel has the highest K and organic carbon content compared to other fruit peel treatments. The content of N, P, K and organic carbon in the palm brown sugar treatment was higher than the white sugar treatment. The results of the analysis of the biological characteristics of the eco-enzyme showed that the total microbe and fungi treated with palm brown sugar were higher than white sugar. The results of the organoleptic test showed that the eco-enzyme has a sour fermented scent and a brownish-yellow to brown color.
Keyword: fermentation, nutrients, organic acid, total microbial population

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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