Judul: Aktivitas Antimikroba Kecombrang (Etlingera elatior) terhadap Mikroorganisme Pembusuk Pangan dan Patogen Bawaan Pangan: Tinjauan Pustaka
Abstrak: Indonesian cuisines have long employed kecombrang as spice, which is also commonly used as a traditional herb. The antimicrobial properties of kecombrang's extracts against food spoilage and foodborne pathogenic microorganisms have been the subject of numerous studies. The objective of this literature review was to study the potential of kecombrang as a source of antimicrobials against pathogens that cause foodborne illness and food spoilage microorganisms. A descriptive review was used to conduct this literature review. Flowers, shoots, fruits, leaves, rhizomes, and the entire plant are among the kecombrang parts that are extracted for antimicrobial testing utilizing solvent extraction, distillation, liquid CO2 extraction, and fractionation. Proteus vulgaris, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Bacillus subtilis, Listeria monocytogenes, Bacillus cereus, and Cryptococcus neoformans are among the microorganisms that can be inhibited by kecombrang extract with similar activity to corresponding control. The essential oil from the kecombrang flower and rhizome exhibits strong antimicrobial activity (MIC <0.60 mg/mL) against a variety of Gram-positive and Gram-negative bacteria along with yeasts. Cryptococcus neoformans is the most susceptible towards flower essential oil, whereas Salmonella enteritidis is the most susceptible towards rhizome essential oil., Masakan Indonesia telah lama menggunakan kecombrang sebagai rempah, yang juga biasa digunakan sebagai ramuan tradisional. Sifat antimikroba ekstrak kecombrang terhadap mikroba pembusuk makanan dan patogen bawaan makanan telah menjadi subyek dari berbagai penelitian. Kajian pustaka ini bertujuan untuk mempelajari potensi kecombrang sebagai sumber antimikroba terhadap patogen penyebab penyakit bawaan makanan dan mikroorganisme pembusuk makanan. Tinjauan deskriptif digunakan untuk melakukan tinjauan literatur ini. Bunga, pucuk, buah, daun, rimpang, dan seluruh tanaman dari kecombrang telah diekstraksi dan telah diuji sebagai agen antimikroba dengan menggunakan ekstraksi pelarut, distilasi, ekstraksi CO2 cair, dan fraksinasi. Proteus vulgaris, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Listeria monocytogenes, Bacillus cereus, Klebsiella pneumoniae, dan Cryptococcus neoformans adalah mikroorganisme yang dapat dihambat oleh ekstrak kecombrang dengan aktivitas yang mirip dengan kontrol yang sesuai. Minyak atsiri dari bunga dan rimpang kecombrang menunjukkan aktivitas antimikroba yang kuat (MIC <0,60 mg/mL) terhadap berbagai bakteri Gram-positif dan Gram-negatif bersama dengan ragi. Cryptococcus neoformans paling rentan terhadap minyak atsiri bunga, sedangkan Salmonella enteritidis paling rentan terhadap minyak atsiri rimpang.
Keyword: Antimicrobial, foodborne pathogen, Food spoilage, kecombrang

Judul: Aktivitas antimikroba ekstrak jahe (Zingiber officinale Roscoe) terhadap beberapa bakteri patogen
Abstrak: hazards to the human health. Ginger (Zingiber officinale Roscoe) is commonly used as traditional medicine. It has a potential as antimicrobial agent by inhibit or kill microbes in dose dependent manner. The principle compounds of ginger are essential oils and non volatile compounds which maximum have antimicrobial activity. The objectives of this research are: (1) to study the yield of ginger extracts by multistage maceration with different polarity solvents, (2) to study antimicrobial activity of hexane, ethyl acetate and ethanol extract of ginger against foodborne pathogen such as Staphylococcus aureus, Bacillus cereus and Salmonella enterica serovar Typhimurium. Ginger extracts were prepared by multistage maceration method using solvent hexane, ethyl acetate and ethanol. The ginger extracts were assayed for antimicrobial activity by agar well diffusion method with Diameter Inhibition Zone (DIZ) and dillution broth method. The yield of hexane, ethyl acetate and ethanol ginger extracts from multistage maceration were respectively 3,57; 3,17; 3,02 g/100 g dry ginger. The DIZ value for Staphylococcus aureus were 5,0; 5,7; 1,3 mm with hexane, ethyl acetate and ethanol ginger extracts respectively 6,1; 6,6; 6,0 mm for Bacillus cereus and Salmonella Typhimurium were show no inhibitory zone. This results showed that the ginger extracts from multistage maceration have a weak antimicrobial activity (1,3 – 6,6 mm) against Gram-positive bacterial. The inhibition activity was determined for ethyl acetate ginger extract that showed the relatively highest inhibition zone. The minimum inhibition concentration did not reach in a range concentration between 5 – 20 mg/ml against Staphylococcus aureus and Bacillus cereus, therefore ginger extracts from multistage maceration with rotavapor temperature 50 o C and freeze dry process were not efficient to developed as natural antimicrobial.
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Judul: Best Difference Equation Aproximation to Duffing 's Equation
Abstrak: Persamaan Duffing merupakan persamaan yang sering muncul sebagai model masalah sistem ayun mekanis atau pada masalah rangkaian listrik. Umumnya penyelesaian persamaan ini secara numerik memberikan hampiran dengan gala! yang tinggi, seperti dengan metode Runge-Kutta. Tulisan ini mengkonstruksi suatu persamaan beda untuk menghampiri persamaan Duffing tersebut. Penyelesaian dari persamaan beda ini melibatkan fungsi-fungsi eliptik Jacobi. Berdasarkan penyelesaian ini diperoleh basil bahwa penyelesaian hampirannya persis sama dengan penyelesaian analitiknya. Penyelesaian analitik yang diperolehjuga melibalkan fungsi-fungsi eliptik Jacobi.
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