Judul: Meta-analisis Pengaruh Penambahan Bawang Putih terhadap Mutu   Mikrobiologi Produk Daging
Abstrak: Garlic (Allium sativum) is one of the natural ingredients used in microbiological quality control of meat products. Various studies have shown that the addition of garlic to meat products can significantly reduce the number of microbes, but some studies show a decrease in the number of microbes that is not significant. Therefore, it is necessary to carry out a thorough and systematic study using meta-analysis to analyze the effect of adding garlic in various forms on the microbial content in meat products using meta-analysis, determine the form of garlic that is most effective in reducing the number of microbes, determine the type/shape meat products that experienced the highest microbial reduction, and determining the types of microbes with the highest inhibition through subgroup analysis of the effect of the addition of garlic on decreasing the number of microbes in meat products. This meta-analysis study was limited to reducing the number of microbes in meat products which included the parameters of garlic shape, type of meat product, and type of microbes tested. This research was conducted in 6 stages, namely formulation of research questions, determination of inclusion and exclusion criteria, search and selection studies, collection of study sources, data extraction, and data analysis. Based on the search and selection for study sources, 304 data extracted from 10 articles were analyzed using the Hedges' d method with a random-effect model. Data processing was done using OpenMEE software. Then an analysis of the overall effect size was carried out to determine the effect of decreasing the number of microbes in meat products using a meta-analysis of various studies that have been conducted. This analysis also tested study heterogeneity, subgroup analysis, and publication bias analysis. Subgroup analysis was carried out to determine which meat products experienced the highest microbial reduction, the form of garlic that was most effective in reducing microbial counts, and the types of microbes that were most inhibited by the addition of garlic. The results of the analysis of the overall effect size (SMD/Standardized Mean Difference) showed a negative value of -1.177 with a confidence interval range (95% CI) from -1.337 to -1.017. The results of this analysis indicated that the addition of garlic to meat products significantly reduced the number of tested microbes (p < 0.05). The resulting heterogeneity value (I2 > 50%) is 54,37%. This heterogeneity value is quite high for each parameter, so it is necessary to carry out further analysis, namely subgroup analysis on various moderator variables, namely the type of sample, the shape of the garlic, and the type of microbe tested. The addition of garlic significantly decreased the number of microbes (p < 0.05) in 3 types of samples, namely raw meatballs (minced mutton meat), ground beef, and raw chicken meat. Forms of garlic that reduce the number of microbes higher are freeze-dried powder, oven-dried powder, and microcapsules essential oil. The addition of garlic to meat products significantly reduced the 7 tested microbes other than Staphylococcus aureus with the highest reduction found against Listeria monocytogenes. Analysis of publication bias was carried out using the funnel plot method and
Keyword: antimicrobial, bacteria, garlic, meat product, meta-analysis

Judul: Meta Analisis Pengaruh Minyak Atsiri dan Ekstrak Rempah Terhadap Mutu Mikrobiologi Produk Berbasis Daging dan Unggas
Abstrak: Foodborne disease merupakan penyakit yang timbul akibat mengkonsumsi pangan yang mengandung kontaminan berbahaya, salah satunya mikroorganisme. Produk daging dan unggas kaya akan kandungan protein sehingga produk mudah rusak akibat pertumbuhan mikroorganisme. Penggunaan rempah-rempah dari sumber, bentuk dan metode pengaplikasian yang berbeda terbukti mampu mereduksi mikroorganisme pada produk daging dan unggas, namun menunjukkan hasil yang berbeda. Penelitian ini bertujuan untuk melakukan kajian pengaruh minyak atsiri dan ekstrak dari rempah terhadap mutu mikrobiologi pada produk daging dan unggas serta menganalisis pengaruhnya berdasarkan sumber rempah, kelompok mikroorganisme dan metode aplikasi yang berbeda terhadap penurunan jumlah mikroorganisme produk daging dan unggas menggunakan pendekatan meta analisis parameter Hedges. Sebanyak 240 data total diperoleh dari 10 artikel akhir hasil seleksi 1256 total artikel yang terkumpul berdasarkan seleksi Preferred Reporting Items for Systematic Reviews (PRISMA) dan dilakukan pengolahan menggunakan Meta Essential software. Hasil meta analisis menunjukkan bahwa penggunaan minyak atsiri rempah (SMD: -4.37; 95%CI -5.63 s.d -3.10; I2 = 83.32%) berpengaruh signifikan terhadap kualitas mikrobiologi produk daging/unggas dalam bentuk mentah dan olahan (sosis, patties atau burger) dibandingkan dengan ekstrak rempah (SMD: -3.66; 95%Cl -4.56 s.d -2.76; I2 = 84.85%). Dalam bentuk minyak atsiri maupun ekstrak penggunaan rempah menunjukkan dampak yang positif terhadap penurunan kelompok mikroorganisme diantaranya total plate count SMD -5.59 ; 95%CI -7.75 s.d -3.61; I2= 85.60), enterobacteriaceae (SMD -5; 95%CI -7.21 s.d -2.79; I2= 87.35%), coliform (SMD -4.22; 95%CI -6.69 s.d -1.75; I2= 88.76%) dan bakteri patogen (SMD -4; 95%CI - 5.79 s.d -2.2; I2= 77.50%). Sage merupakan jenis rempah yang dalam bentuk minyak atsiri maupun ekstrak menunjukkan pengaruh yang signifikan dalam mereduksi kelompok mikroorganisme, kecuali bakteri patogen. Perbedaan metode pengaplikasian minyak atsiri (SMD -4.36; 95% CI: -6.09 s.d -2.62; I 2= 83.32%) dan ekstrak (SMD –3.67; 95% CI: -3.77 s.d -3.58; I 2= 84.85%) menunjukkan pengaruh yang signifikan dalam mereduksi jumlah mikroorganisme produk daging/unggas. Metode pencelupan merupakan metode terbaik dalam mengaplikasian rempah dalam bentuk minyak atsiri. Sedangkan dalam bentuk ekstrak, pengaplikasian terbaik dilakukan dengan cara menambahkan ekstrak ke dalam produk daging/unggas merupakan metode terbaik.
Keyword: meta-analysis, spices, antimicrobial, meat/poultry-based products

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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