Judul: Pengaruh Heat Moisture Treatment terhadap Sifat tekstural dan Retrogradasi Gel Pati Aren dan Tapioka
Abstrak: Heat Moisture Treatment (HMT) is one of physical modification techniques that uses limited moisture where heating process at high temperature is implemented for certain period of time. This research studied the effect of HMT modification on textural properties and retrogradation of aren and tapioca starch gel. HMT modification was done by using autoclaving method at 120 oC in 60 minutes for tapioca and 90 minutes for aren. Before autoclaving process, the water content of starch was adjusted into 20% (b/b, wb). The observation of retrogradation was done on starch gel with water content 10% (b/b, db) and refrigerated at 4 oC for 7 days. Textural analysis was done by doing compression using texture analyzer. Degree of retrogradation analysis was done by analyzing the changes of hardness from starch gel, and analyzing amylose hydrolisis using α-amylase enzyme. The result from textural analysis and degree of retrogradation analysis show that HMT modification could make starch gel become fragile, shown by decreasing breaking strain. From degree of retrogradation analysis, it is known that HMT modification increased hardness and degree of retrogradation of starch gel. According to this research, it can be concluded that HMT modification could make starch gel become fragile, increase hardness, and increase retrogradation of native starch gel.
Keyword: textural properties., retrogradation, heat moisture treatment

Judul: Karakter Fisikokimia dan Kadar Pati Resisten Tapioka Hasil Modifikasi Heat Moisture Treatment (HMT) Menggunakan Oven
Abstrak: Tapioka dimodifikasi dengan heat-moisture treatment (HMT) pada suhu 120ºC dan 140ºC selama 16 dan 24 jam dengan kadar air 20% . Selama HMT, terjadi penurunan kadar air sekitar 73,38 - 85,95 %, sehingga kadar air HMT aktual hanya 3 - 4 % . Proses HMT menyebabkan hilangnya sifat birefringence di tengah beberapa granula tapioka, penurunan kristalinitas (kecuali untuk HMT tapioka 120-24) tetapi tidak mengubah tipe kristalin dari tapioka. Kandungan amilosa, kapasitas pembengkakan dan kelarutan tapioka HMT lebih rendah dari tapioka alami. HMT tapioka memiliki kadar RDS dan SDS yang secara signifikan lebih tinggi dari bentuk alaminya (kecuali tapioka HMT 120-24) sedangkan kadar RS tidak berbeda nyata . HMT menyebabkan perubahan karakteristik pasta pati . Viskositas puncak, suhu pasting dan viskositas breakdown relatif pasta dari tapioka HMT secara signifikan lebih rendah dibandingkan tapioka alami. Secara umum, perubahan dari semua parameter sangat dipengaruhi oleh kondisi proses .
Keyword: tapioka, HMT, karakter fisikokimia, RS, suhu, waktu

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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