Judul: Nutritional Analysis and Shelf Life Estimation of  Banana Chips by Accelerated Shelf-Life Testing (ASLT)
Abstrak: Produk yang ingin diperdagangkan di Indonesia harus memiliki label pada kemasannya. Keterangan yang wajib dicantumkan pada label adalah tanggal kadaluarsa produk. Informasi nilai gizi merupakan informasi penting bagi konsumen karena dapat mempengaruhi pola makan konsumen. Tujuan penelitian ini adalah menganalisis komposisi gizi, mengidentifikasi perubahan mutu pada berbagai suhu, dan menghitung umur simpan produk keripik pisang. Analisis gizi dilakukan menggunakan metode analisis proksimat terhadap tiga varian rasa keripik pisang. Perubahan mutu yang diamati adalah susut bobot, kadar air, kadar asam lemak bebas (%FFA), dan mutu organoleptik keripik pisang yang disimpan pada suhu kamar (30±1° C), 40±1° C, dan 50±1° C. Umur simpan dihitung menggunakan metode Accelerated Shelf-Life Testing (ASLT) melalui persamaan Arrhenius. Seratus gram keripik pisang rasa balado, sapi panggang, dan jagung bakar masing- masing mengandung air 2.80 g, 2.54 g, dan 2.62 g; karbohidrat 69.77 g, 67.49 g, dan 71.25 g; protein 1.05 g, 1.38 g, dan 1.05 g; lemak 22.58 g, 23.18 g, dan 21.78 g; serta energi total 486.47 kkal, 474.50 kkal, dan 470.19 kkal. Perubahan mutu yang terjadi adalah kenaikan bobot keripik, kadar air, dan kadar asam lemak bebas serta penurunan tingkat kesukaan terhadap keripik pisang. Umur simpan keripik pisang adalah 265 hari pada suhu penyimpanan 25°C., A product traded in Indonesia must have a label on its packaging. Information that must have included is its expired date. Nutritional information is important for consumers because it could relate to the consumer dietary patterns. The purpose of this study was to analyze nutrient composition, identify quality changes at various temperatures, and calculate the shelf life of banana chips. Nutritional analysis was carried to proximate analysis in three flavors of banana chips. Quality changes observed included weight loss, moisture content, free fatty acid levels (%FFA), and organoleptic at room temperature (30±1°C), 40±1°C, and 50±1°C. The shelf life of the product estimated with Accelerated Shelf-Life Testing (ASLT) method. A hundred grams of balado, barbecue, and roasted corn flavored banana chips respectively contains water 2.80 g, 2.54 g, and 2.62 g; carbohydrates 69.77 g, 67.49 g and 71.25 g; protein 1.05 g, 1.38 g, and 1.05 g; fat of 22.58 g, 23.18 g, and 21.78 g; and total energy 486.47 kcal, 474.50 kcal, and 470.19 kcal. Quality changes that occur are an increase in the weight of chips, moisture content, and levels of freefatty acids and a decrease in the level of preference for banana chips. The shelf life of banana chips is 265 days at storage temperature of 25°C.
Keyword: accelerated shelf-life testing, banana chips, nutrition fact, shelf life

Judul: Physical, Chemical, Sensory Characteristics, and Shelf Life of Tempe Chips
Abstrak: Keripik tempe merupakan salah satu bentuk diversifikasi dari pengolahan tempe sehingga produk tempe lebih awet. Di Indonesia, jenis keripik tempe yang beredar di pasaran adalah keripik tempe konvensional dan keripik tempe tapioka. Penelitian ini bertujuan membandingkan karakteristik fisik, kimia, dan sensori serta menentukan umur simpan keripik tempe yang dikemas dalam kemasan standing pouch aluminum foil. Analisis dilakukan dengan membandingkan keripik tempe produksi Rumah Tempe Azaki dengan keripik tempe komersial yang sudah beredar di pasaran yang akan dijadikan sebagai kontrol. Hasil penelitian ini menunjukkan bahwa semakin tinggi proporsi tapioka yang digunakan sebagai bahan baku, maka semakin tinggi nilai oHue, kerenyahan, kadar karbohidrat, dan penilaian panelis terhadap karakteristik sensorinya. Selain itu, semakin tinggi proporsi kedelai yang digunakan sebagai bahan baku, maka semakin tinggi kadar abu, kadar lemak, kadar protein, dan kadar serat kasar. Keripik tempe tapioka dengan perbandingan kedelai dan tapioka sebesar 50:50 (b:b) cenderung lebih disukai dari segi warna, aroma, rasa, tekstur, dan keseluruhan, sedangkan keripik tempe konvensional cenderung kurang disukai dibandingkan kontrol (komersial). Umur simpan keripik tempe tapioka dan keripik tempe konvensional ditentukan berdasarkan parameter kritis kadar asam lemak bebas. Umur simpan keripik tempe tapioka yang dikemas dalam kemasan standing pouch aluminum foil pada suhu 27 dan 30 oC berturut-turut selama 71 dan 69 hari. Umur simpan keripik tempe konvensional yang dikemas dalam kemasan standing pouch aluminum foil pada suhu 27 dan 30 oC berturut-turut selama 68 dan 66 hari, Tempe chips are one of diversification of tempe processing so that tempe products are more durable. In Indonesia, the types of tempe chips on the market are conventional tempe chips and tapioca tempe chips. This study examines to compare the physical, chemical, and sensory characteristics and determine the shelf life of tempe chips that packaged in standing pouch aluminum foil. The analysis was carried out by comparing tempe chips produced by Rumah Tempe Azaki with commercial tempe chips already sold in the market which will be used as control. The results of this study showed that the higher the proportion of tapioca used as raw material, increased oHue values, crispness, carbohydrate content, and panelists assessment of sensory characteristics. In addition, the higher the proportion of soybean used as raw material, increased the ash content, fat content, protein content, and crude fiber content. Tapioca tempe chips with a ratio of 50:50 (w:w) soybean and tapioca tend to be preferred in terms of color, aroma, taste, texture, and overall, while conventional tempe chips tend to be less favorable than control (commercials). The shelf life of tapioca tempe chips and conventional tempe chips was determined based on the critical parameter of free fatty acid content. The shelf life of tapioca tempe chips that packaged in standing pouch aluminum foil at temperatures of 27 and 30 oC was 71 and 69 days respectively. The shelf life of conventional tempe chips that packaged in standing pouch aluminum foil at a temperature of 27 and 30 oC for 68 and 66 days respectively
Keyword: fisik, keripik tempe konvensional, keripik tempe tapioka, kimia, umur simpan, physical, conventional tempe chips, chemical, shelf life, tapioca tempe chips

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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