Judul: Retensi Vitamin A dan β-karoten Minyak Sawit yang Difortifikasi Selama Penggorengan
Abstrak: Palm oil can be a good carrier of the vitamin A fortification due to its stability and its wide cooking application, so its consumption contributes to community’s nutrition. The objective of this research is to get information about the effect of fortificants to retention of vitamin A and β-carotene in fortified palm oils. Four palm oils used in this research were palm oil fortified with β-karoten from red palm olein (RPO) 47.08 IU/g, fortified with vitamin A 59.69 IU/g, fortified with combination A (30 IU RPO, 15 IU vitamin A) 45.64 IU/g and fortified with combination B (15 IU RPO, 30 IU vitamin A) 45.95 IU/g. Fortified oils were used to fry tofu by three replicated shallow frying and to stir-fry sprouts. The result showed that the retention of fortificants decreased by frying replication. In the first day of frying, the retention of fortificants were not significanly different (p=0.05), in a range 85.52%-88.22%. In the second and third frying, it was known that β-karoten had lower stability than vitamin A as fortificant. Fortificant combination A and B had the same stability. The peroxide value of the oils increased until the second frying, then decreased in the third frying. The free fatty acid (FFA) percentage increased minimally, except palm oil fortified with vitamin A, the FFA remained same. The highest yield of fortificant in cooked sprouts was vitamin A (63.37%), followed by combination B (53.42%), combination A (50.60%), and RPO (34.86%).
Keyword: vitamin A, retention, red palm olein, fortification, β-carotene

Judul: Kinetika Degradasi Aktivitas Vitamin A pada Minyak Goreng Sawit Difortifikasi Campuran Retinil Palmitat dan Minyak Sawit Merah Kaya β-Karoten Dibimbing
Abstrak: Kekurangan vitamin A (KVA) berpotensi mengganggu kesehatan masyarakat dan merusak kualitas sumber daya manusia Indonesia. Salah satu solusi penanggulangan KVA yaitu melalui fortifikasi vitamin A ke dalam bahan pangan. Strategi fortifikasi vitamin A ke dalam bahan pangan minyak goreng sawit dianggap cocok, logis dan direkomendasikan diaplikasikan di negara berkembang dan mempunyai populasi besar seperti Indonesia. Penelitan ini menggunakan sampel minyak goreng sawit dengan kondisi awal yang berbeda-beda (Pvi ±0, ±4 dan ±8 mEq/kg) sehingga dapat diketahui kondisi ideal minyak goreng sawit yang akan difortifikasi. Bahan fortifikan yang digunakan dalam penelitian ini adalah campuran retinil palmitat dan MSM kaya β-karoten, sehingga dapat diketahui stabilitas aktivitas vitamin A dalam minyak goreng sawit selama penyimpanan. Dosis campuran fortifikan pada penelitian ini memenuhi syarat dosis vitamin A dalam minyak goreng sawit sesuai SNI 7709:2012, yaitu minimal 45 IU per gram minyak goreng sawit (BSN 2012). Variasi rasio dosis pencampuran fortifikan adalah 30 IU retinil palmitat dan 15 IU β-karoten minyak sawit merah per gram minyak goreng sawit; kemudian 15 IU retinil palmitat dan 30 IU β-karoten minyak sawit merah per gram minyak goreng sawit. Sampel minyak disimpan pada suhu 60±5; 75±5; dan 90±5ºC selama 7 (tujuh) titik waktu penyimpanan (t1, t2, t3... t7). Hasil penelitian menunjukkan minyak berbilangan peroksida awal ±0; 4; dan 8 mEq/kg yang difortifikasi campuran retinil palmitat dan MSM kaya β- karoten mempunyai laju peningkatan bilangan peroksida, laju degradasi aktivitas vitamin A, dan laju pembentukan asam lemak bebas yang relatif tidak berbeda, semakin tinggi bilangan peroksida awal minyak sebelum difortifikasi maka semakin cepat laju kerusakan minyak selama penyimpanan. Pada suhu penyimpanan yang rendah perubahan konstanta laju reaksi pembentukan bilangan peroksida minyak akibat perubahan suhu penyimpanan minyak yang difortifikasi campuran 30 IU retinil palmitat dan 15 IU minyak sawit merah kaya β-karoten lebih lambat daripada minyak yang difortifikasi campuran 15 IU retinil palmitat dan 30 IU minyak sawit merah kaya β-karoten, namun pada penyimpanan suhu yang tinggi (900C) peningkatan bilangan peroksida pada minyak tersebut justru lebih cepat. Hal ini berarti, jika minyak disimpan pada suhu ruang (sekitar 300C) maka laju peningkatan bilangan peroksida pada minyak yang difortifikasi campuran 30 IU retinil palmitat dan 15 IU minyak sawit merah kaya β-karoten akan lebih lambat dibandingkan minyak yang difortifikasi campuran 15 IU retinil palmitat dan 30 IU minyak sawit merah kaya β-karoten.
Keyword: β-carotene, degradation, fortification, kinetics, palm cooking oil, retinyl palmitate

Judul: Mathematical model of Hematopoietic Stem Cell in Chronic Myelogenous Leukemia with and without Therapy
Abstrak: Leukemia or blood cancer is a diverse group of neoplastic disease, characterized by the multiplication of abnormal leukocytes or malignant transformation of blood-forming cells in bone marrow and lymphoid tissues. One of the most common types of leukemia is Chronic Myelogenous Leukemia (CML), which is usually diagnosed by the presence of certain chromosomal abnormalities, the so-called Philadelphia chromosome (Ph). One of the treatments of CML is Granulocyte Colony-Stimulating Factor (G-CSF). In this paper, we discuss two Hematopoietic Stem Cell (HSC) models, i.e. HSC without treatment and HSC with G-CSF treatment. The model of HSC without treatment included three equations representing the dynamics of HSC, leukocyte and platelet. Whereas, the model of HSC with G-CSF treatment includes the previous three equations and adds two more equations representing G-CSF injection and G-CSF circulation. The stability behavior of the system approaching the equilibrium points in the simulation study is carried out using Mathematica 7.0. The simulation results show that the G-CSF treatment can successfully decrease the number of HSC, which means reducing the CML.
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