Judul: Proses Steam blasting Kedelai Grobogan serta Pengaruhnya Terhadap Perubahan Fisikokimia dan Bioasesibiltas Kalsium secara in vitro.
Abstrak: BPPT telah mengembangkan alat steam blasting skala pilot plant untuk mengolah kedelai mentah. Proses pretreatment ini merupakan hidrolisis termal menggunakan steam dengan suhu dan tekanan tinggi yang diikuti dengan dekompresi eksplosif. Penelitian ini bertujuan: 1) menerangkan pengaruh variabel produksi yang berbeda terhadap kualitas fisikokimia kedelai grobogan, 2) menerangkan kinetika perubahan fisikokimia kedelai grobogan selama proses steam blasting, 3) menentukan variabel produksi yang tepat dan mampu menghasilkan kedelai grobogan steam blast yang memenuhi persyaratan kematangan, dan 4) menerangkan pengaruh steam blasting terhadap kemampuan absorpsi kalsium kedelai grobogan Pada penelitian ini, digunakan 5 dan 10 kg bahan baku kedelai basah (75% dan 50% volume ruang kosong) pada tabung steam blast. Kedelai tersebut diproses pada suhu dan tekanan yang berbeda [115 °C (P = 1 bar), 125 °C (P = 2 bar), dan 135 °C (P = 3 bar)] serta waktu proses yang berbeda pula [5, 10, 15, 20, dan 25 menit). Sampel kemudian dianalisis kenampakan visualnya, hardness, indeks urease, protein dispersibility index (PDI), protein solubility index (PSI), SDSPAGE, dan bioasesibilitas kalsiumnya. Semakin tinggi suhu dan lama pemanasan, semakin tinggi pula nilai skor visual biji kedelai. Adapun nilai hardness dan nilai b semakin menurun sementara nilai ΔE semakin tinggi. Penurunan nilai hardness dan nilai b (kekuningan) kedelai dapat dijelaskan dengan kinetika ordo 1. Parameter kinetika reaksi pada nilai hardness adalah kT=115°C=0.0217 menit-1, kT=125°C=0.0339 menit-1, kT=135°C=0.0376 menit-1, dan Ea=36.382 Kj.mol-1 (untuk 75% volume ruang kosong); dan kT=115°C=0.0201 menit-1 , kT=125°C=0.0312 menit-1, kT=135°C=0.0424 menit-1, dan Ea=49.220 Kj.mol-1 (untuk 50% volume ruang kosong). Parameter kinetika reaksi pada nilai b adalah kT=115°C=0.0188 menit-1 , kT=125°C=0.0178 menit-1, kT=135°C=0.0242 menit-1, dan Ea=16.425 Kj.mol-1 (untuk 75% volume ruang kosong); serta kT=115°C=0.0159 menit-1 , kT=125°C=0.0152 menit-1, kT=135°C=0.0218 menit-1, dan Ea=20.555 Kj.mol-1 (untuk 50% volume ruang kosong). Secara kimiawi, steam blasting mampu menurunkan nilai indeks urease, PDI, dan PSI. Namun, tidak ditemukan model kinetika reaksi yang dapat menjelaskan perubahan kimiawi kedelai dengan baik. Steam blasting kedelai pada suhu 115 °C (P = 1 bar) selama 5 menit untuk kedua volume ruang kosong telah memenuhi persyaratan kedelai matang berkualitas baik. Analisa SDS-PAGE menunjukkan bahwa suhu dan waktu yang lebih tinggi akan menghasilkan protein dengan berat molekul yang lebih rendah. Hasil analisis menunjukkan bahwa proses steam blasting yang memberikan nilai absorpsi kalsium paling tinggi adalah pada suhu 135 °C (P = 3bar) selama 5 menit (19.81±3.80%) dan 15 menit (31.17±6.40%).
Keyword: kedelai grobogan, steam blasting, kinetika reaksi, karakteristik fisikokimia kedelai, bioasesibilitas kalsium

Judul: Mempelajari Proses Steam Blasting Kacang Kedelai, Karakterisasi Warna dan Tekstur Kacang Kedelai serta Sifat Fungsional Protein dari Tepung Kedelai yang Dihasilkan
Abstrak: Soybean (Glycine max L.) is one kind of legume containing high protein, isoflavones, polyunsaturated fatty acid, amino acids, and no cholesterol. Soybean can be used as a raw material of various products, including soy flour. Beside those advantages, soybean contains various anti nutritional compounds such as trypsin inhibitor, phytic acid, and haemaglutinin. These compounds can be removed by heat, but the process can decrease the quality of sensory properties and nutritional value of products. The alternative soybean processing method is using heat and pressure treatment. An equipment that works based on heat and pressure treatment is steam blasting. The principle of this equipment is by splitting soybeans through a short heating process and the pressure drops suddenly. This study aimed to obtain an optimum pressure and time of steam blasting in soybean flour processing. The pressure used were 1,2,3,4, and 5 bar with heating time 5, 10, 15, 20, and 25 minutes. Tests conducted were SDS-PAGE assay (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis) and soybean quality index assay like KOH Protein Solubility (KOH PS) assay, Protein Dispersibility Index (PDI) assay, and Urease Index assay. The result showed that at 1 bar pressure treatment with a 5 minute heating time could increase the solubility of soy proteins in neutral solution, eliminate most of antinutrition in soy, prevent overheat or underheat, and produce good quality soybean flour. Test statistics of various parameters (KOH PS, PDI, urease index) also showed that the treatment pressure of 1 bar 5 minutes is the most efficient treatment and meets the recommended soybean quality based on value of KOH PS, PDI, and urease index. Treatment pressure of 1 bar 5 minutes was not significantly different from the higher pressure treatment on KOH PS test and PDI, but significantly different in urease index test. Thus, treatment pressure of 1 bar with a 5 minute meet the adequacy standard of soybean heat processing. Meanwhile, SDS-PAGE assay showed that at 3 bar pressure treatment with a 25 minute heating time, all the dominant antinutrition substances in soybean was inactivated because denatured by heat and pressure. Those antinutrition substance were lipoxygenase, Bowman-Birk inhibitor, and lectin. Physical observations were conducted on soybean yield blasting process showed a change in color and texture with increasing in pressure and heating time. Soybean colour become increasingly brown color, due to the Maillard reaction and the oxidation of carotenoids found in soy. Soybean texture become increasingly soft, caused by high temperature and saturated steam which can damage and destroy the structure of soybean cotyledon compact.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology