Judul: Salmonella spp. Contamination on Chicken Carcasses and Risk Profile in the Distribution Chain in Jakarta
Abstrak: Provinsi Jakarta adalah salah satu provinsi di Indonesia dengan tingkat konsumsi protein tinggi, terutama dari karkas ayam. Salmonella spp. adalah bakteri patogen yang sering ditemukan pada karkas ayam dan dapat menyebabkan penyakit terbawa makanan. Tujuan dari penelitian ini adalah untuk menentukan prevalensi Salmonella spp. pada karkas ayam dan titik kendali kritis berdasarkan profil risiko dalam rantai distribusi di Provinsi Jakarta. Penelitian ini dilakukan dengan mengumpulkan data surveilans dari lembaga pemerintah, analisis kuantitatif Salmonella spp. terduga, survei implementasi good practices, pemeringkatan risiko, dan analisis sensitivitas. Prevalensi tingkat kontaminasi ditentukan dengan metode hitung cawan menggunakan media selektif XLT4 agar. Profil risiko dilakukan dengan pemeringkatan risiko dan analisis sensitivitas. Simulasi Monte Carlo sebanyak 100.000 iterasi diterapkan dengan menggunakan Oracle Crystal Ball®. Prevalensi tertinggi kontaminasi Salmonella spp. di Jakarta selama 2019-2023 ditemukan pada karkas ayam yang didistribusikan melalui pasar tradisional, dengan nilai prevalensi 41,86% dan konsentrasi Salmonella terduga 1,09±0,12 log CFU/g. Diikuti oleh karkas ayam yang didistribusikan dari TPHU (Tempat Pemotongan Hewan Unggas), prevalensi nilainya 17,65% dengan konsentrasi Salmonella terduga 1,92 ± 1,11 log CFU/g. Prevalensi kontaminasi Salmonella spp. untuk produk karkas ayam yang didistribusikan melalui pasar ritel modern adalah 0%. Analisis sensitivitas menunjukkan aspek paling penting adalah suhu kendaraan transportasi yang berkontribusi sebesar 12,3% terhadap risiko kontaminan untuk TPHU dan metode pembersihan peralatan yang berkontribusi 38% terhadap risiko kontaminan untuk pasar tradisional. Profil risiko menunjukkan bahwa aspek yang memiliki kontribusi tinggi terhadap tingkat risiko kontaminan dan bisa menjadi titik paling kritis yang perlu dikendalikan., Jakarta is one of province in Indonesia with high level of protein consumption especially for chicken carcasses. Salmonella spp. is pathogenic bacteria which frequently found in chicken carcasses and could cause food borne disease. The aim of this study were to determined Salmonella spp. prevalence in chicken carcasses and critical control point based on risk profile in Jakarta distribution chain. The study was conduct by compiled surveillance data from government institution, quantitative analysis of Salmonella spp. presumtive, good practice implementation survey, constructed risk ranking and analysis sensitivity. Prevalence of contaminant level determined by plate count method with selective media XLT4 agar. Risk profile was involved risk-ranking and sensitivity analysis. Monte Carlo simulation of 100,000 iterations was applied by using Oracle Crystal Ball®. The highest prevalence of Salmonella spp. contamination in Jakarta during 2019-2023 found in chicken carcasses that distributed through traditional markets, prevalence value was 41.86% with concentrations presumptive Salmonella spp is 1.09 ± 0.12 log CFU/g. Followed by chicken carcasses distributed from traditional TPHU, prevalence value was 17.65% concentration of 1.92± 1.11 log CFU/g. Prevalence of Salmonella spp. contamination for chicken carcass products that were distributed through modern retail markets is 0%. Sensitivity analysis indicated the most important aspect were temperature of transportation vehicle that contribute 12.3% to risk contaminant for TPHU and equipment cleaning method that contribute 38% to risk contaminant for traditional market. Highest rank correlation shown that those aspects had high contribution to risk level of contaminant and could be the most critical point to be controlled.
Keyword: Chicken Carcass, Salmonella spp., Critical point, Risk profile, Sensitivity analysis

Judul: Prevalence and Contamination Risk Profile of  Salmonella spp. on Chicken Carcasses in Retail in the West Java Region
Abstrak: Jawa Barat merupakan salah satu daerah utama penyedia ayam di Indonesia Bakteri Salmonella spp. merupakan bakteri patogen penyebab penyakit bawaan pangan yang dapat mengkontaminasi karkas ayam salah satunya karena penangangan yang salah di tahap ritel. Penelitian ini bertujuan untuk menghitung prevalensi dan jumlah kontaminasi serta menentukan faktor kritis kontaminasi Salmonella spp. di tahap ritel. Sampel penelitian berasal dari 12 kota/kabupaten di wilayah Jawa Barat. Metode penelitian dilakukan melalui penghimpunan data sekunder, pengambilan data survei, analisis kuantitatif Salmonella spp. menggunakan metode spread plate count dengan media selektif agar XLT4, serta profil risiko dengan analisis sensitivitas melalui simulasi Monte Carlo 10.000 iterasi menggunakan software Oracle Crystall Ball. Hasil penghimpunan data sekunder diperoleh prevalensi kontaminasi Salmonella spp. sebesar 78% (n=363). Hasil analisis kuantitatif Salmonella spp. pada karkas ayam yang berasal dari pasar OKtradisional menunjukkan prevalensi 65% (n=40) dengan konsentrasi 3.25± 0.71 Log CFU/g, dan dari ritel modern menunjukkan prevalensi sebesar 40% (n=30) dengan konsentrasi 0.24±0.79 Log CFU/g. Analisis sensitivitas menunjukkan nilai kontribusi pada aspek yang paling penting yaitu pengemasan saat displai (33.5%), kebersihan fasilitas displai (26.5%) dan suhu displai (10.9%). Korelasi peringkat tertinggi menunjukkan bahwa aspek-aspek tersebut mempunyai kontribusi yang tinggi terhadap tingkat risiko kontaminasi dan dapat menjadi faktor prioritas untuk dikendalikan., West Java was one of the main regions supplying chickens in Indonesia. Salmonella spp. Bacteria were pathogenic bacteria that caused foodborne illnesses and could contaminate chicken carcasses, partly due to mishandling at the retail stage. This study aimed to calculate the prevalence and level of contamination, as well as identify critical factors of Salmonella spp. contamination at the retail stage. The study samples were taken from 12 cities/regencies in the West Java region. The research methods included collecting secondary data, conducting surveys, and performing a quantitative analysis of Salmonella spp. using the spread plate count method with XLT4 selective agar media, and developing a risk profile with sensitivity analysis through 10,000 iterations of Monte Carlo simulation using Oracle Crystal Ball software. The secondary data collection results showed a prevalence of Salmonella spp. contamination of 78% (n=363). The quantitative analysis results for Salmonella spp. on chicken carcasses from traditional markets showed a prevalence of 65% (n=40) with a concentration of 3.25±0.71 Log CFU/g, while those from modern retail showed a prevalence of 40% (n=30) with a concentration of 0.24±0.79 Log CFU/g. Sensitivity analysis indicated the most critical factors were packaging during display (33.5%), display facility cleanliness (26.5%), and display temperature (10.9%). The highest rank correlation showed that these factors significantly contributed to the contamination risk level and could be the priority factors to control.
Keyword: contamination, chicken carcass, risk, Salmonella spp, ritel

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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