Judul: Review on Purification Method of Glucomannan from Porang Corm (Amorphophallus muelleri Blume) and Its Potential Application in Food Products
Abstrak: Umbi porang (Amarphophallus muelleri Blume syn Amarphophallus oncophyllus Prain) merupakan salah satu umbi lokal yang mempunyai nilai ekonomi tinggi karena mengandung glukomanan sehingga berpotensi untuk dikembangkan di Indonesia. Kandungan glukomanan yang tinggi (20 – 60%) dalam umbi porang membuat glukomanan dalam umbi porang dapat diekstrak dan diaplikasikan pada produk pangan, baik sebagai bahan tambahan pangan maupun pangan dengan manfaat untuk kesehatan. Telaah ini bertujuan memberikan gambaran mengenai beberapa metode purifikasi glukomanan dari umbi porang dan potensi aplikasi pada produk pangan. Metode telaah meliputi pendeskripsian topik, penelusuran pustaka, seleksi pustaka, serta analisis dan interpretasi pustaka. Hasil telaah menunjukkan metode purifikasi glukomanan dari umbi porang dapat dilakukan dengan metode mekanis, kimiawi, serta dengan bantuan enzim, asam, dan ultrasonik. Perbedaan metode dan kondisi purifikasi menghasilkan karakteristik fisikokimia glukomanan yang berbeda. Metode purifikasi tersebut menghasilkan glukomanan dengan kadar kemurnian yang memenuhi standar, yaitu 60 – 92,69%. Metode purifikasi yang menghasilkan glukomanan dengan karakteristik fisikokimia paling baik adalah metode mekanis menggunakan stamp mill, kombinasi ball mill dan maserasi etanol, ultrasound-assisted extraction, serta maserasi etanol konsentrasi bertingkat. Beberapa penelitian telah membuktikan bahwa glukomanan dari umbi porang berpotensi diaplikasikan pada produk pangan, baik sebagai bahan tambahan pangan maupun sebagai pangan dengan manfaat untuk kesehatan., Porang tuber (Amarphophallus muelleri Blume syn Amarphophallus oncophyllus Prain) is one of the local corms that has high economic value because it contains glucomannan so it has the potential to be developed in Indonesia. The content of glucomannan in porang corm is high (20 – 60%) so that it can be extracted and applied in the food products, both as a food additive and as a food with health benefit. This literature review aimed to provide an overview of several methods on purifying glucomannan from porang corms and their potential applications in food products. The method of review included topic descriptions, literature searches, literature selection, and literature analysis and interpretation. The results of review showed that the method of purifying glucomannan from porang corms could be carried out by mechanical and chemical methods, as well as method which involve the enzymes, acid, and ultrasonics. The different purification methods and conditions resulted in different physicochemical characteristics of glucomannan. The purification methods in this review produced glucomannan with a purity level that meets the standards, i.e: 60 – 92.69%. The purification method producing glucomannan with the best physicochemical characteristics was a mechanical method using a stamp mill, combination of ball mill and ethanol maceration, ultrasound-assisted extraction and multilevel ethanol maceration. Several studies had proven that glucomannan from porang corms had the potential to be applied to food products, both as a food additive and as food with health benefit.
Keyword: glukomanan, glukomanan porang, umbi porang, purifikasi, glucomannan, porang glucomannan, porang corms, purification

Judul: Optimization of Oxalate Content Decrease in Kathak Porang Bulbil (Amorphophallus sp.) Flour Through Immersion in Warm NaHCO3 Solution
Abstrak: Umbi porang (Amorphophallus sp.) merupakan komoditas yang diminati karena memiliki kandungan serat pangan yang tinggi. Porang dapat berkembang biak dari bulbil yang disebut kathak. Bulbil kathak porang dapat dipanen dalam jumlah yang produktif. Akan tetapi, terdapat keterbatasan lahan untuk mengembangbiakkannya. Maka dari itu, muncul kekhawatiran akan berlebihnya stok bulbil kathak porang di masa yang akan datang sehingga potensi penggunaannya sebagai bahan pangan perlu diteliti. Salah satu bahan pangan yang dapat diolah dari umbi-umbian adalah tepung, tetapi bulbil kathak mengandung oksalat yang kadarnya perlu diturunkan terlebih dahulu. Optimasi proses perendaman dalam larutan NaHCO3 hangat dapat menurunkan kadar oksalat pada umbi-umbian. Tepung yang telah melalui proses optimum akan dikarakterisasi proksimat, kadar glukomanan, warna, densitas kamba, dan profil gelatinisasi. Tepung dengan penurunan kadar oksalat optimum (62,70%) diperoleh dengan perlakuan perendaman dalam larutan NaHCO3 hangat konsentrasi 6% dengan durasi perendaman 60 menit. Tepung yang telah melewati proses optimum masih mengandung kadar air, abu, dan oksalat yang cukup tinggi serta derajat putih yang kurang baik sehingga diperlukan optimasi lebih lanjut. Berdasarkan profil gelatinisasinya, tepung bulbil kathak porang memiliki setback viscosity yang rendah sehingga cocok diaplikasikan sebagai pengental atau penstabil pada produk pangan., Porang tubers (Amorphophallus sp.) is a commodity with great demand due to its high content of dietary fiber. Porang can be cultivated from bulbil called kathak. Bulbil kathak porang can be harvested in productive quantity. However, the land to cultivate them is limited. Therefore, there’s a concern of excessive kathak porang bulbil stock in near future, so the study for its potential use as food is necessary. One of the foodstuffs that can be processed from tubers is flour, but kathak porang bulbil has oxalate content which needs to be decreased first. Optimization of the immersion process in warm NaHCO3 solution can decrease oxalate content in tubers. Flour that has gone through the optimum process will be characterized by proximate, glucomannan content, color, kamba density, and gelatinization profile. The flour with optimum decrease of oxalate content (62,70%) was obtained by immersion in warm 6% NaHCO3 solution for 60 minutes. The flour that has gone through the optimum process had high water, ash, and oxalate content, and also a less preferred whiteness degree, therefore it still needs further optimization. Based on the gelatinization profile, kathak porang bulbil flour had low setback viscosity thus suitable to be thickener or stabilizer in foodstuffs.
Keyword: bulbil kathak porang, NaHCO3, oksalat, tepung

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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