Judul: Development Of Texturized Vegetable Protein (Tvp) Made From Fermented Hyacinth Flour (Lablab Purpureus (L.) Sweet) And Its Application In Meatball
Abstrak: Nowadays, people are more conscious in consuming low cholesterol foods. This phenomenon makes Texturized Vegetable Protein (TVP) becomes popular. However, the most commonly used for producing TVP is soybean which is not self-supporting in Indonesia. It directs to find an alternative substitute of soybean, such as komak/hyacinth (Lablab purpureus (L.) sweet). It is a tolerant bean and contains globulin protein that the ratio of 7S and 11S is similar to soy bean. It also has high protein (21-28%) but low fat (less than 1%). Those made hyacinth becomes a potential to be TVP without require fat extraction process. Therefore the objective of this research was to produce TVP from mixture of hyacinth bean (75% and 90%) and gluten flour (10% and 25%) afterwards evaluate its characteristics and also its application in meatball which is acceptable in terms of chemical, physical and organoleptic properties. A preliminary experiment was conducted to determine the appropriate processing conditions. The barrel temperature, screw speed, and moisture content of feed were varied to obtain texturized products with optimal characteristics. The result showed that moisture level of the ingredients should be adjusted to 20%, the barrel temperature of twin screw extruder was 130-1400C, and the screw speed was at 35 RPM, 12 Hz. Hyacinth based textured vegetable protein is prepared by double screw extrusion for structuring protein. The fermentation technique was used in this research to increase the protein digestibility. The results indicated that fermented THP (Texturized Hyacinth Protein) had higher in protein content, and water holding capacity but lower density than unfermented THP. These differences were significant (P < 0.05). In addition, THP prepared with 25% gluten had the psychochemical properties which close to commercial TSP (Texturized Soy Protein). Subtitution of 30% beef meat with fermented THP flour in preparing meatballs were still acceptable in organoleptic test and has fulfilled Indonesia national standards (SNI 01–3818–1995). Furthermore, this subtitution had an advantage in lowering cholesterol and in increasing dietary fiber.
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Judul: Optimasi Proses Ekstrusi Texturized Vegetable Protein di PT XYZ
Abstrak: Texturized vegetable protein (TVP) adalah salah satu produk daging tiruan (meat analogue) yang dibuat dengan memodifikasi stuktur protein nabati sehingga teksturnya menyerupai daging. Kelebihan yang dapat diperoleh dari daging tiruan adalah dapat menurunkan risiko penyakit dan dapat dikonsumsi oleh seseorang yang tidak dapat mengkonsumsi daging, baik karena masalah kesehatan atau kepercayaan. Protein merupakan salah satu nutrisi yang dibutuhkan tubuh. Penggunaan texturized vegetable protein telah mengalami peningkatan sebagai pengganti sumber protein. Penelitian ini bertujuan untuk mendapatkan kombinasi variabel proses yang optimum, yang mampu menghasilkan produk sesuai dengan target perusahaan. Volume permintaan TVP PT. XYZ terus meningkat, namun jumlah mesin produksi terbatas. Perusahaan perlu mengoptimalkan mesin yang ada untuk memenuhi permintaan tersebut. Faktor yang digunakan untuk penelitian ini adalah kapasitas aliran tepung, kapasitas aliran air, kecepatan putaran ulir, dan suhu ekstruder. Parameter respon yang digunakan adalah kadar air, daya serap air, bulk density, warna, dan bentuk butiran. Pengujian sampel dilakukan sebanyak 21 kali run dengan dua kali pengulangan. Data akan dianalisa menggunakan statistik ANOVA (Analysis of Variance) pada masing-masing respon untuk melihat signifikansi setiap faktor terhadap respon. Kemudian proses optimasi akan dilakukan menggunakan bantuan software Design Expert 10 (DX-10). Metode yang digunakan adalah RSM (Response Surface Method). Data kombinasi faktor yang paling optimum adalah: kapasitas aliran tepung sebesar 225 kg/jam; kapasitas aliran air 35,54 Hz (71,08 liter/jam); suhu ekstruder 130,70 oC; dan kecepatan putaran ulir sebesar 375,18 rpm. Hasil verifikasi yang diperoleh menunjukkan nilai masing – masing respon berada di dalam kisaran Confident Interval (CI). Penelitian optimasi ini menggunakan ekstruder ulir ganda yang memiliki rasio panjang terhadap diameter sebesar 24 dan diameter ulir 65mm. Sumber protein yang digunakan pada penelitian ini adalah tepung kedelai bebas lemak (defatted soy flour). Penelitian lain yang sejenis dilaporkan menggunakan ekstruder dengan ulir tunggal maupun ulir ganda namun dengan diameter ulir yang berbeda. Sumber protein yang digunakan bervariasi., Texturized vegetable protein (TVP) is one of the meat analogue products made by modifying the structure of vegetable protein become meat-like texture. The advantages could be obtained from the meat analogue. It could reduce the risk of disease and could be consumed by someone who could not consume meat, either because of health problems or beliefs. Protein is one of the nutrients that the body needs. The use of texturized vegetable protein has increased as a substitute for protein sources. This research aimed to obtain the optimum combination of process variables, which was able to produce products according to the company's target. The TVP demand volume of PT. XYZ continued to increase, but the number of production machines were limited. The Companies need to optimize the existing machines to meet their customer demands. The factors that were used for this research were flour flow capacity, water flow capacity, screw rotation speed, and extruder temperature. The response parameters that were used were water content, water absorption, bulk density, color, and grain shape. The data is collected by 21 runs that was repeated twice for each run. The data was analyzed using ANOVA (Analysis of Variance) on each response to observe the significance of each factor on the response. Then the optimization process
Keyword: extruder, optimization, RSM, TVP, meat analogue

Judul: Analisis Kestabilan pada Model Epidemik SIR dengan Waktu Diskret
Abstrak: Model epidemik merupakan model matematika yang digunakan untuk menganalisis perilaku penyebaran penyakit menular. Salah satu model epidemik adalah model epidemik SIR. Model epidemik SIR terdiri atas tiga subpopulasi, yaitu individu rentan 𝑆���� (susceptible), individu terinfeksi 𝐼���� (infected), dan individu yang telah sembuh dan kebal terhadap penyakit 𝑅���� (recovered). Model epidemik SIR yang dibahas adalah model epidemik SIR dengan waktu diskret yang dijelaskan oleh persamaan beda. Pada model tersebut diperoleh titik tetap beserta kestabilannya. Simulasi numerik dilakukan untuk menunjukkan perilaku dinamis pada model tersebut. Hasil simulasi menunjukkan bahwa pemilihan nilai parameter ℎ, yaitu ukuran langkah, akan mempengaruhi sistem. Jika nilai ℎ dinaikkan, maka terjadi perubahan pada jumlah titik tetapnya, semakin besar nilai ℎ maka akan terjadi perilaku chaos atau kekacauan. Perubahan pada nilai parameter selain ℎ tidak mempengaruhi kestabilan pada sistem, sehingga bertambahnya titik tetap hanya dipengaruhi oleh parameter ℎ.
Keyword: SIR, discrete, fixed point, stability, chaos