Judul: Karakteristik Fisikokimia dan Sifat Fungsional Tempe yang Dihasilkan dari Berbagai Varietas Kedelai
Abstrak: Tempe is an Indonesian traditional food made by fermentation of soybean by the fungus Rhizopus sp. The objective of this research was to compare physical and chemical properties of soybean and tempe made from import (Import 1, Import 2) and local (Local 1, Local 2, Local 3) soybeans. For tempe production, soybean were sorted, soaked, dehulled, cooked, and fermented. The result showed that Local 1 variety presented as the biggest size (19.53 g/100 soybean grains) and the highest cost effectiveness (0.73). Despite of those physical properties, yields of all tempe weren’t significantly different (p>0.05). Tempe made from soybean Local 1 had moisture, protein, and fat content as higher as tempe made from import soybeans. Tempe made from soybean Local 3 had the highest protein content (52.70%). The antioxidant capacity of tempe made from import and local soybeans were about 186-191 mg AEAC/g, but weren’t significantly different (p>0.05). Based on sensory evaluation of raw and fried tempe, overall tempe made from local soybeans had the same preference with tempe made from import soybeans. Tempe made from soybean Local 1 had shelf life until 2 days at room temperature and 7 days at low temperature based on sensory quality measurement.
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Judul: Perbandingan Karakteristik Fisikokimia Tempe Dengan Tempe Kecambah Kedelai
Abstrak: Tempe adalah salah satu makanan tradisional Indonesia hasil fermentasi kedelai. Inovasi diperlukan untuk meningkatkan kualitas tempe, baik secara fisik maupun kimia. Penduduk Indonesia gemar mengonsumsi tempe karena beberapa alasan, yaitu harganya relatif murah dan nilai gizinya tinggi. Salah satu proses yang dapat meningkatkan mutu gizi dan kualitas tempe adalah dengan memodifikasi bahan baku tempe, yaitu mengganti kedelai dengan kecambah kedelai. Dalam penelitian ini, dipelajari perbandingan karakteristik fisikokimia tempe kedelai (TK) dan tempe kecambah kedelai (TKK). Kedelai dikecambahkan dalam waktu 28 jam. Kecambah kemudian diproses menjadi tempe (TKK). TKK dan TK dianalisis kekerasan dan sifat sensorinya. Pengeringan beku dilakukan untuk TKK dan TK selama 26 jam. Tempe kering beku digiling menjadi tepung. Tepung tempe digunakan untuk analisis fisik dan kimia. Penggunaan kecambah kedelai terbukti mempengaruhi kualitas tempe. TKK memiliki 53.37 % bk protein, 24.97 mg AEAC/100 g tempe bk kapasitas antioksidan, 5.08 mg/100 g bk, 81.75 mg/100 g bk isoflavon, dan beberapa mineral (Ca, P, Fe, Zn) yang lebih tinggi dari TK. Secara fisik, kedua jenis tempe memiliki tekstur yang sama, tetapi tepung TKK mempunyai derajat putih (72.47 %) dan densitas kamba (0.42 g/ml) yang lebih tinggi dari TK. Tepung TKK juga memiliki aktivitas air (0.63) dan repose angle (39.94o) yang lebih rendah. Hasil analisis sifat fungsional protein menunjukkan bahwa tepung TKK memiliki daya serap air (2.26 g/g), daya serap minyak (1.45 ml/g), dan kapasitas emulsi (11.42 %) yang secara signifikan lebih tinggi (p<0,05) dari tepung TK. Hasil evaluasi sensori menggunakan uji rating hedonik terhadap tempe mentah menunjukkan bahwa atribut warna dan aroma kedua jenis tempe berbeda nyata (p<0.05), sedangkan hasil evaluasi sensori pada tempe goreng menunjukkan bahwa atribut warna, aroma, rasa, dan tekstur pada kedua jenis tempe berbeda nyata (p<0.05).
Keyword: chemical characteristic, germinated soybean tempe, physical characteristic, sensory profile, soybean tempe

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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