Judul: Rice Bran Protein Hydrolysate and Its Antioxidant Activity
Abstrak: Rice bran was generally used as animal feed, while it contains many potential compounds. With hydrolysis reaction, small peptides can be obtained from rice bran protein, in which it showed higher antioxidative activity. The antioxidative activity of rice bran protein hydrolysate from fractionated rice bran was studied in this work. Albumin, globulin, glutelin and prolamin protein fractions were fractionated by its solubility and hydrolyzed with two type of enzyme, pepsin and proteaseM, at various digestion times. Albumin fraction showed high degree of hydrolysis for both enzyme hydrolysis. Protease M digestion showed different digesting ability towards different protein fractions, in which it has low impact on glutelin and prolamin fraction. Pepsin hydrolysis resulted in higher degree of hydrolysis compared to protease M digestion. After 30 minutes of hydrolysis time, hydrolysis reaction slowed down and antioxidant activity remained constant in pepsin hydrolysis. Prolamin and glutelin in pepsin digestion showed the highest activity of ABTS radical scavenging (4.02 mM and 3.93 mM TEAC) compared to the other hydrolysates. Rice bran protein hydrolysates showed much higher in antioxidant activity compared to the undigested rice bran protein which can be explained antioxidant activity derived from rice bran peptides
Keyword: antioxidant, hydrolysate, protein, rice_bran

Judul: The Effect of Accelerated Aging on the Characteristic Properties of Rice Bran
Abstrak: Accelerated aging process using thermal processing has been reported as an alternative way to produce aged rice. Rice bran is a by-product of rice production containing many bioactive compounds, which give beneficial effect to human health. Effect of accelerated aging on functional properties of rice grain and flour has already been discussed. However, the consequence of the accelerated aging technique on the characteristic properties of the rice bran has to be investigated and verified. Moreover, the investigation of accelerated aging on the rice bran is quite limited. The objective of this research is to investigate the effect of accelerated aging using high-temperature fluidized bed drying followed by tempering and ventilation on the dietary fibre (insoluble and soluble dietary fibre), lipid rancidity, and antioxidant activity properties of rice bran. Based on the experimental results it was found that the rice bran properties after accelerated aging process namely, alcohol-soluble and water-soluble acidity, free fatty acids content, total phenolic content, and antioxidant activity significantly affected the aged rice bran properties. The accelerated aging process using high-temperature could decrease acidity and free fatty acids contents of rice bran oil. Moreover, the accelerated aging was found to exhibit decreased of total phenolic content and reducing power of rice bran extracts. The reducing power of rice bran extracts were associated with the total phenolic content. However, the total dietary fibre of rice bran had no significantly different. The accelerated aging could be used to stabilization process for rice bran before further utilization. These process could be produce low acidity and free fatty acid content of rice bran oil production.
Keyword: Bogor Agricultural University (IPB), antioxidant, acidity, dietary fibre, accelerated aging, rice bran

Judul: Penyelesaian Masalah Pelabelan Graf vertex Magic pada Graf Cycle Sederhana
Abstrak: Graf vertex magic adalah suatu graf memiliki nilai bilangan magic yang sama pada masing-masing vertex yang berbeda. Graf cycle sederhana adalah suatu walk tertutup yang mengandung setidaknya tiga vertex, semua vertex-nya berbeda dan setiap vertex terhubungkan oleh satu edge.
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