Judul: Pengaruh Perlakuan Panas Terhadap Kerenyahan dan Warna Keripik Ubi Jalar
Abstrak: Sweet potato (Ipomoea batatas) is one of staple food which abundant in Indonesia. There are some kind of sweet potato, such as white sweet potato, yellow sweet potato, and purple sweet potato. Beside of carbohydrate and fibers, purple sweet potato has some functional character, because it contains anthocyaninas a pigment in purple sweet potato. A method to increase the value of purple sweet potato is by processing it into chips. Crispness and colour of chips are factors which are important to the quality of chips. Research on the effect of boiling and steaming to the crispness and colour of sweet potato chips will be implemented. Boiling and steaming aims to create conditions, so the slices of sweet potato gelatinization expands and becomes more crispy when fried. Some parameters which involved in steaming process need to be optimized, so the chips with the best crispness and colour are gained. The main parameters which playing role in steaming process are temperature and time. The crispness and colour of the chips will be measured objective and subjectively.
Keyword: sweet potato, steaming, crispness, colour, boiling

Judul: Pengaruh Perlakuan Fisik Terhadap Kualitas Pasta Ubi Jalar Ungu (Ipomoea batatas L.).
Abstrak: Ubi jalar ungu merupakan sumber bahan pangan yang memiliki banyak manfaat namun belum dimanfaatkan secara optimal. Hal itu menyebabkan ubi jalar berpotensi untuk diolah lebih lanjut untuk ditingkatkan kualitas fungsionalnya. Perlakuan fisik merupakan salah satu cara untuk meningkatkan kualitas pasta ubi jalar. Pemanasan dapat menyebabkan gelatinisasi dan terjadinya pelunakan jaringan daging ubi jalar ungu dan menginaktivasi polifenol oksidase dan peroksidase sehingga kerusakan enzimatis antosianin selama ekstraksi dapat ditekan. Penelitian ini bertujuan untuk meningkatkan kualitas pasta ubi ungu dengan perlakuan fisik. Perlakuan yang digunakan dalam penelitian ini adalah pengukusan (suhu 100oC selama 15 menit), microwave (power level 100% selama 3 menit), dan Heat Moisture Treatment (HMT) (suhu 121oC selama 1 jam dengan tiga kali siklus). Berdasarkan hasil analisis, pasta ubi kukus memiliki kadar antosianin tertinggi yaitu 156,10 mg/100g dan nilai IC50 yang dihasilkan sebesar 5,95 ppm, nilai viskositas 9150 cP dan total gula 69,5%. Pasta ubi jalar ungu dengan perlakuan microwave memiliki nilai viskositas (15300 cP), total gula (72,63%) dan gula pereduksi (8,06%) tertinggi. Pada modifikasi pasta ubi jalar ungu HMT diperoleh viskositas (6500 cP) dan total gula (59,83%) terendah dengan kadar antosianin (81,19 mg/100g) dan aktivitas antioksidan (IC50 9,01 ppm) lebih tinggi dari pasta ubi jalar ungu microwave. Kata kunci : heat moisture treatment, microwave, pengukusan , ubi jalar ungu
Keyword: heat moisture treatment, microwave, purple sweet potato, steaming

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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