Judul: Optimization of Nutmeg Flesh Hydrolysis using Amylase and Pectinase Enzymes
Abstrak: Nutmeg is a very potential commodity in Indonesia. Utilization of nutmeg pulp left over from wasted seeds and mace needs to be improved. Nutmeg flesh contains active ingredients that are very beneficial for health. The cell wall of nutmeg fruit also contains many components such as fiber, starch and pectin. To increase the active ingredient content, enzymes are used to break down the cell wall components such as starch and pectin degrading enzymes. Enzymatic hydrolysis is needed to break down starch and pectin compounds using the enzymes amylase and pectinase. The optimum conditions for the amylase and pectinase enzymes are different, so an optimization process is needed to obtain optimal results. This study aims to find optimal conditions for hydrolysis of amylase and pectinase synergistically and to compare the antioxidant content of fresh nutmeg pulp and hydrolyzate of nutmeg pulp. The optimization process was carried out using the Box Behnken Design (BBD) design on RSM with 17 experimental point units with 3 factors namely pH (X1), temperature (X2), and time (X3) as well as 3 responses namely Dextrose Equivalent, reducing sugar, and sugar total of each treatment variation. The results showed that the components of pectin (4,95%) and starch (8,13%) were obtained. From these experiments, RSM provided several optimum conditions for a process with optimal solution conditions validated at pH 4,62, temperature 46oC, and 181 minutes and produced dextrose equivalent (41,05), reducing sugar (7,08%,) and total sugar (17,55%). The factors of pH, temperature, and hydrolysis time contributed to the resulting response value. The response values of dextrose equivalent, reducing sugar and total sugar increased with increasing temperature and time up to a certain limit and the process conditions tended to be at a low pH up to a certain limit. The higher the response value indicates that the process of hydrolysis and breakdown of starch and pectin is running better. The level of clarity in the validated nutmeg pulp hydrolyzate was still quite turbid where the TSS (26,3 g/L) and TDS (35,3 g/L) values were obtained and the oBrix value was 2.47. These results show that the degradation process of pectin into simpler compounds is not perfect. The antioxidant (IC50) content of hydrolyzed nutmeg was 127.64 ppm and the antioxidant (IC50) of fresh nutmeg flesh was 141.78 ppm. These results indicate that the antioxidant content of IC50 increased after hydrolysis.
Keyword: nutmeg flesh

Judul: Peningkatan Kinerja Proses Penyulingan Minyak Pala Dengan Metode Uap Langsung
Abstrak: Nutmeg oil is one of Indonesian important export commodity. For the last six years (1996-2001), it's price in the word market has showed an inclined increasing. In 1999, the nutmeg oil price reached the average price of 26.18 US dollar/kg. In the beginning of 2000, the average price of Indonesian nutmeg oil in the world market returned to increase and achieved the average price of33.38 US dollar/kg. The market opportunity which is still prospective as well as the raw material availability become the fundamental aspect of the developing the nutmeg oil industry in Indonesia. For the time being, essential oil production existing in Indonesia is small scale industry. The common problem which found, was the long distillation duration which takes 48-52 hours for nutmeg kernel distillation and 72 hours for mace distillation. It caused the high consumption of energy/fuel. The condition was very contradictive to the energy prices which is always increase. In the other side, a sceintific point of view considering the optimum material size as well as the uniform vessel pressure distillation in each small sclae distillation factory is not yet being under attention. The objective of this work is to improve the performance of nutmeg oil distillation process by reducing the duration of distillation process. The specific objective is to find out the effect of material size and vessel pressure to the yield and quality of resulted nutmeg oil from the young nutmeg kernel and mace using direct steam distillation method. The size of nutmeg kernel observed in the experiment was categoried in fine, which was the output of 0.3 cm strainer hole diameter mill; semi rough, which was the output of 0.5 cm strainer hole diameter mill; and rough, which was the output of 1.0 cm strainer hole diameter mill. The distillation conducted of a vessel pressure of 0 atm gauge, with a duration of 12 hours. All experiment run was conducted twice. In second experiment stage, the vessel pressure was levelled to 0.5 and 1.0 atm gauge in order to provide a better process condition. This stage was conducted based on the nutmeg kernel size which given the highest yield as the consideration to determine the best atmospheric pressure in the vessel in perspective of resulting the highest nutmeg oil yield and meet the quality standard. All experiment run was conducted twice and with duration 12 hours The average water content of raw material used was 16.84 % (% v/w), while the average oil content of the raw material used was 17.58 % (%v/w, wet basis). The kernel size of 0.5 cm resulted the highest yield of oil compared to the two other kernel size, it has 12.98 % (% v/w, wet basis) or 11.65 % (% w/w, wet basis). As well as distillation rate in a period of two hours. At the end distillation process, the kernel size of 0.5 cm has succeeded to distill the nutmeg oil from the material in amount of 73.83 %. Thus, the kernel size of 0.5 cm was the best yielded material size compared to the two other material size
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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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