Judul: Potensi Daya Hambat Bakteri Asam Laktat terhadap Cendawan pada Dangke Selama Penyimpanan
Abstrak: Dangke is a traditional dairy product in Enrengkang District, South Sulawesi. Since dangke is produced traditionally in small scale unit (home industry) the microbial contamination of dangke is critical point in food quality and safety, specifically the fungal contamination of fungi. It is necessary to develop a method to inhibit growth of fungi in dangke. Lactic acid bacteria (LAB) could be a potential biopreservative of dangke regarding to inhibition of fungal contamination. The aim of this research was to review the effectiveness of inhibition of LAB against fungi in dangke during storage. The study was devided into three steps, i.e., observation of fungal number in dangke (n=20), isolation and identification of fungi in dangke, and observation of Lactobacillus plantarum DU15 (LAB) application in dangke which was contaminated with Candida sp. The study was designed using randomized completely design with factorial pattern of 4 x 2 x 4 with 5 replications. The result showed that the average number of fungi in 20 samples of dangke from Enrekang District were 5.2 x 106 cfu/g. The main isolated fungi strains were belonged to Candida sp. (95%), Saccharomyces sp. (50%), Geotrichum sp. (35%), Rodotorula sp. (10%), Microsporum sp. (40%), Cladosporium sp. (30%), Penicillium sp. (30%), Aspergillus sp. (20%), Fusarium sp. (5%). During the storage, pH, total lactic acid, and viable count of LAB increased significantly (p<0.05). LAB could reduce fungal growth significantly (p<0.05). The number of fungi decreased from 6.72 log cfu/g to 3.99 log cfu/g after 6 days of storage
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Judul: Characteristics, Antioxidant and Antihypertensive Properties of Buffalo Milk Dangke with the Addition of Lactiplantibacillusplantarum subsp. plantarum IIA-1A5 asProbiotics during Cold Storage
Abstrak: Dangke adalah makanan tradisional khas Kabupaten Enrekang, Sulawesi Selatan. Terbuat dari susu kerbau atau susu sapi yang digumpalkan dengan enzim papain getah buah pepaya. Pengembangan strain Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5 sebagai probiotik dalam berbagai produk makanan telah terbukti meningkatkan kandungan senyawa bioaktif diantaranya sifat antioksidan, agen antihipertensi, dan antibakteri. Penelitian ini bertujuan mengevaluasi kualitas fisik, mikrobiologi dan sifat fungsional dangke berupa antioksidan dan antihipertensi dengan penambahan Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5 pada taraf 0 % dan 10 % selama penyimpanan 0, 5 dan 10 hari pada suhu dingin (±4 °C). Hasil uji fisik menujukkan perbedaan signifikan pada dangke dengan penambahan Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5 sebanyak 10 % dan lama penyimpanan yang mampu meningkatkan nilai pH, menurunkan nilai TAT dan menurunkan nilai tekstur. Penambahan Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5 10 % pada dangke mampu menghambat dan menurunkan pertumbuhan bakteri patogen seperti E. coli dan S. aureus serta mampu meningkatkan nilai aktivitas antioksidan dan antihipertensi sebesar 83,45 % dan 45, 60 %. Berdasarkan hasil elektroforesis, profil protein berupa ß-kasein ditemukan pada berat molekul 29 kDa di susu kerbau dan ß-laktoglobulin ditemukan dalam dangke pada berat molekul 18 kDa akibat adanya protein kasein yang terhidrolisis., Dangke is a traditional food from South Sulawesi, especially Enrekang Regency, made from buffalo or cow milk coagulated with papaya fruit sap papain enzyme. The development of Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5 as a probiotic in various food products has been shown to increase the content of bioactive compounds, such as antioxidants, antihypertensive agents, and antibacterials. This study aims to evaluate the physical, microbiological, functional quality of dangke in the form of antioxidant and antihypertensive properties with the addition of Lactiplantibacillua plantarum subsp. plantarum strain IIA-1A5 at the level of 0 % and 10 % during storage for 0, 5 and 10 days. The results of the physical test showed significant differences in dangke with the addition of Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5 as much as 10 % and storage duration, which increase the pH value, decrease TAT value and were able to lower texture value. The addition of Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5 10 % in dangke was able to inhibit and reduce the growth of pathogenic bacteria such as E. coli and S aureus and was able to increase the value of antioxidant and antihypertensive activity by 83.45 % and 45.60 %. Based on the electrophoresis results, the protein profile of ß-casein was found at a molecular weight of 29 kDa in buffalo milk, and ß-lactoglobulin was found in Dangke at a molecular weight of 18 kDa due to the presence of hydrolyzed casein protein.
Keyword: antihypertensive, antioxidant, dangke, Lactiplantibacillus plantarum subsp. plantarum strain IIA-1A5.

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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