Judul: Pengembangan Produk Makanan Ringan Dengan Proses Ekstrusi Dan Penggorengan
Abstrak: A typical Indonesian meal is based on rice cooked alone or prepared with sambal, a hot chili condiment ; it is served with krupuk (crackers made of flour , vegetables and meat , shrimp or spices) .Some local dishes such as Soto and Oxtail Soup are topped with fried shallot and crackers (something crispy and crunchy). The purpose of this experiment is to develop crackers which can be function as snacks alone or as seasoned fried toppings for eating with rice or other basic meal. In soupy dish, this toppings can turned to a synthetic meat which has a plastic or elastic and full body mouth feel. Available equipment in the company which has high technical possibility to produce this snacks are several extruders in the rice noodle (bihun) line and snack extruder (third generation snacks or pellets). The best process design is needed to produce a crispy snacks by using one prototype formula consists of ground catfish (Clarias batrachus L) meat and tofu (function as protein source), cassava flour (gaplek). The best prototype from laboratory scale formulation process has protein content 14 %, tasty and enough saltiness level and crispy texture. Raw material cost estimation per kg product dough cost from Rp.5.895,- to Rp.6.765,-. The combined process of rice noodle extruder with meat processor or meat chopper extruder, produced the best crispiness product after frying process with production capacity 500 kg/hour. The study of comparing the effect of dough temperature prior to extrusion process and the impact of meat processors or meat chopper extruder (MCE) in producing a crispy product was made by using the same frying condition 150° C ~ 3 minutes in a continuous noodle fryer. Proof on the crispiest texture is based on texture analysis on crispiness level. The higher the value of kgf for a product, the crispier the texture is. Duncan statistical calculation differentiates the process flow into 7 crispiness groups. The highest value of kgf is 93.2 and the lowest value is 24.49. Minimum value which considered as crispy is 50-55 kgf. Extrusion process begins with maximum 30 °C dough through strap extruder (bihun Line) then followed by MCE produced the crispiest texture. Cool dough (maximum 30 °C) significantly produced crispier texture than hot dough (60-90 °C). Based on Contrast Orthogonal Test, process followed with MCE and without MCE is significantly different at significance level <0.0001<0.05. Product texture made of extrusion process followed with MCE is perceived as significantly crispier if compared to that of extrusion process without MCE. Supporting studies of exposing product on top of soupy dishes (as topping) such as instant noodle at certain timing showed that the crispier the texture, the faster water absorption into the capillary of product structure.
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Judul: Rheological characteristic of corn noodles made with extrusion process
Abstrak: This research generally aimed to prepare corn-based noodles which have good elasticity and low cooking loss by using extrusion process. In detail, this research has the objective to: (1) study the effects of particle sizes, amounts of corn flour and corn starch in water, concentration of salt in corn flour and corn starch on gelatinization profile; (2) to optimize corn noodle extrusion using RSM, and (3) to study the effect of salt addition and number of passing in extruder on corn noodle characteristics. The gelatinization profile of corn flour and corn starch were characterized by Brabender Visco Amylograph type D-4100 Duisburg. Corn noodles were prepared by Scientific Laboratory Single Screw Extruder type LE25-30/C from Labtech Engineering Co. Ltd., Thailand. Process optimization was conducted by using response surface methodology (RSM) with four parameters, i.e., 1) firmness; 2) stickiness, 3) elongation and 4) cooking loss. Firmness and stickness was set in range, elongation was set in maximum, and cooking loss was set in minimum. It was found that the initial temperature and maximum temperature of gelatinization increased and peak viscosity decreased with the increase of particle sizes. Increasing concentration of corn flour and corn starch in water tended to decrease maximum temperature of gelatinization and increase peak viscosity, but it had no significant effect on initial temperature. The addition of sodium chloride Process optimization showed that the optimum condition, with a desirability of 0.835, was achieved by the combination of 70% (dry basis) dough’s moisture content with the extruder temperature is 90in corn flour increased significantly initial gelatinization temperature, maximum temperature of gelatinization, peak viscosity and cold viscosity. In the case of corn starch, the addition of sodium chloride 1% increased initial temperature and peak viscosity, but the addition more than 1% of concentration had no significant effect. The addition of sodium carbonate in corn flour and corn starch increased the initial temperature and peak viscosity, but decreased maximum temperature of gelatinization and cold viscosity. o In general, this research showed that firmness of corn noodle decreased by the increased of salt addition and by number of passing in extruder. In sodium carbonate addition, the optimum condition was obtained at moisture content of 80% (dry basis), salt concentration of 0.11 or 0.12%, and number of passing in extruder for 3 times (desirability 0.836). Under this optimum condition, predicted by RSM, corn noodles has firmness of 2242.29 gf, stickiness of -58.83 gf, elongation of 418.81%, and cooking loss of 3.66%. In sodium chloride addition, the optimum condition was achieved at moisture content of 80% (dry basis), salt concentration 2%, and number of passing for 3 times (desirability 0.877). Under this condition, predicted by RSM, corn noodles has firmness of 1855.23 gf, stickiness of -35.86 gf, elongation of 576.38%, and cooking loss of 2.62%.
Keyword: Corn starch, Wheat salt noodle

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular