Judul: Physicochemical and Sensory Characteristics of Dried Beef Lung with Honey Addition as Antioxidant
Abstrak: Pengolahan dendeng pada penelitian ini menggunakan bahan dasar paru sapi sebagai produk samping daging untuk meningkatkan nilai gunanya. Madu ditambahkan sebagai antioksidan untuk mencegah reaksi oksidasi. Tujuan penelitian ini adalah untuk menganalisis pengaruh penambahan madu terhadap karakteristik fisikokimia dan sensorik dendeng paru sapi. Penelitian menggunakan rancangan acak lengkap satu faktor dengan perlakuan penambahan madu karet pada konsentrasi yang berbeda (0%, 5%, 10% dan 15% berdasarkan bobot paru) dengan 3 ulangan. Hasil penelitian menunjukkan bahwa penambahan madu karet dengan konsentrasi 15% dan ditambah 15% gula merah pada dendeng paru sapi menurunkan nilai pH, aw, kadar air dan meningkatkan aktivitas antioksidannya secara nyata (p<0,05). Penambahan madu karet pada dendeng paru sapi tidak berpengaruh nyata terhadap tingkat keempukan, intensitas rasa bumbu, parameter warna dan rasa tetapi berpengaruh nyata (p<0,05) terhadap parameter aroma, tekstur, intensitas rasa madu, intensitas bau bumbu dan bau madu pada uji hedonik dan uji mutu hedonik. Penambahan konsentrasi madu karet pada taraf 15% madu karet dan 15% gula merah menunjukkan hasil terbaik yang dapat memperbaiki mutu dendeng paru sapi., In this study dried beef lung was processed using lung as meat by product to increase its value. Honey was added as antioxidant to prevent oxidation reaction. The aim of this study was to analyzed the effect of honey addition on physicochemical and sensory characteristics of dried beef lung. This study designed by using one-factor completely randomized design with different rubber honey concentration (0%, 5%, 10% and 15% based on lung weight) with 3 replication. The results showed that the addition of rubber honey with a 15% concentration and 15% brown sugar in dried beef lung had a significant effect (p<0,05) can reduce pH, aw, water content and increase value of antioxidant activity. The addition of rubber honey to dried beef lung had no significant effect for tenderness level, flavor intensity of spices, color and taste parameters, but had a significant effect (p<0,05) for aroma and texture parameters, intensity aroma of spices and honey, and intensity taste of honey on hedonic test and hedonic quality test. The addition of 15% rubber honey and 15% brown sugar showed the best result can improve quality of dried beef lung.
Keyword: antioksidan, dendeng paru, fisikokimia, madu, organoleptik, antioxidant, dried lung, honey, physicochemical, sensory

Judul: Characteristics of Beef Dendeng Added by Fresh Red Ginger (Zingiber officinale var. Rubrum) as A Seasoning
Abstrak: Dendeng merupakan produk olahan daging yang dapat mengalami ketengikan akibat adanya reaksi oksidasi lipida. Penambahan jahe merah segar sebagai bumbu dapat menghambat pertumbuhan bakteri, meningkatkan aktivitas antioksidan dan berpotensi meningkatkan keempukan. Penelitian ini bertujuan menguji karakteristik dendeng sapi yang diberi penambahan jahe merah segar sebagai bumbu. Penelitian ini menggunakan perlakuan penambahan jahe merah segar dengan konsentrasi sebesar 0%, 12,5% dan 25% dari berat daging. Daging sapi diiris dengan ketebalan 5 mm dan dimarinasi dengan bumbu selama 12 jam. Daging yang telah dimarinasi, dikeringkan dalam oven pada suhu 60 °C selama 3 jam dan dilanjutkan dengan menggunakan suhu 70 °C selama 5 jam. Hasil penelitian menunjukkan bahwa penambahan jahe merah segar pada dendeng mampu meningkatka pH, aw, kadar air, aktivitas penghambatan DPPH, dan kapasitas antioksidan, serta menurunkan tingkat kekerasan, kadar MDA dan TPC. Bakteri Salmonella sp., Escherichia coli dan Staphylococcus aureus tidak terdeteksi keberadaanya pada semua perlakuan dan lama penyimpanan. Berdasarkan keempukan yang dihasilkan, penambahandan jahe merah segar sebesar 12,5% dan 25% pada dendeng sapi matang lebih disukai panelis. Dendeng sapi dengan penambahan jahe merah segar sebesar 25% menunjukkan hasil terbaik untuk pengujian sifat fisikokimia, organoleptik, mikrobiologi, dan aktivitas antioksidan., Dendeng is a processed meat product that can have rancidity due to lipid oxidation and microbiology activity. Adding fresh red ginger as a spices can influencing taste, inhibit the growth of bacteria, increasing antioxidant activity, and potentially increasing tenderness. This study aims to examine the characteristics of beef jerky added by fresh red ginger (Zingiber officinale var. Rubrum) as a seasoning in marination step. This study used the addition of fresh red ginger with proportion 0%, 12,5% and 25% from meet weight. Beef was sliced with a thickness of 5 mm then was marinated with spices for 12 hours. Marinated beef was dried using oven at 60 °C for 3 hours and was continued by using temperature of 70 °C for 5 hours. The results showed that the addition of fresh red ginger to beef jerky was able to increase pH, aw, moisture content, DPPH inhibitory activity, and antioxidant capacity, as well as reduce hardness level, MDA and TPC numbers. Salmonella sp., Escherichia coli and Staphylococcus aureus bacteria were not detected in all treatments and storage time. Based on the tenderness result, the addition of fresh red ginger by 12.5% and 25% in cooked beef jerky was preferred by the panelists. Beef jerky with the addition of 25% fresh red ginger showed the best results for testing the physicochemical, organoleptic, microbiological, and antioxidant activity properties.
Keyword: antioxidant, beef jerky, fresh red ginger, microbiology, sensory

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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