Judul: Modification of DNA Extraction from the DNeasy® mericon® Food Kit for Halal Authentication Gelatin
Abstrak: Gelatin adalah bahan yang banyak digunakan di industri pangan, farmasi, dan kosmetik. Status kehalalan gelatin perlu diperhatikan karena dapat bersumber dari hewan babi. Salah satu metode autentikasi halal gelatin adalah real time-polymerase chain reaction (RT-PCR). Analisis RT-PCR memerlukan ekstrak DNA dengan syarat kemurnian A260/280 sebesar 1,8−2,0 dan konsentrasi 10–100 ng μL-1 agar dapat teramplifikasi. Namun, kemurnian dan konsentrasi ekstrak DNA menggunakan standar protokol kit DNeasy® mericon® Food belum memenuhi syarat analisis RT-PCR. Tujuan penelitian ini adalah memodifikasi ekstraksi DNA dari kit DNeasy® mericon® Food. Modifikasi ekstraksi DNA optimal diperoleh dengan kondisi sistem empat kali pooling, unit proteinase K 0,015 AU, waktu inkubasi 180 menit, dan volume larutan EB 30 μL. Kemurnian ekstrak DNA optimal yang dihasilkan pada A260/280 sebesar 1,8 dan konsentrasi 19,4 ng µL-1. Validasi RT-PCR menghasilkan kurva logaritmik dengan nilai Ct 25,5. Hal ini menunjukan ekstrak DNA dapat digunakan untuk autentikasi halal gelatin menggunakan RT-PCR., Gelatin is an ingredient that is mostly used in the food, pharmaceutical and cosmetic industries. The halal status of gelatin needs to be considered because it can be sourced from animals such as pigs. One method of halal gelatin authentication is real time-polymerase chain reaction (RT-PCR). RT-PCR analysis requires a DNA extract with A260/280 purity requirements of 1,8–2,0 and a concentration of 10–100 ng μL-1 in order to be amplified. However, the purity and concentration of the DNA extract using the standard DNeasy® mericon® Food kit protocol did not meet the requirements for RT-PCR analysis. The aim of this research is to modify DNA extraction from the DNeasy® mericon® Food kit. The optimal DNA extraction modification was obtained with four pooling system conditions, proteinase K units of 0,015 AU, incubation time of 180 minutes, and EB solution volume of 30 μL.The optimal DNA extract purity produced in A260/280 was 1,8 and a concentration of 19,4 ng µL-1. RT-PCR validation produced a logarithmic curve with a Ct value of 25,5. This shows that DNA extract can be used to authenticate halal gelatin using RT-PCR.
Keyword: authentication, extraction, gelatin, halal, RT-PCR

Judul: Volatilomic of Fish and Pork Gelatin Using HS SPME GC-MS for Halal Authentication
Abstrak: Gelatin merupakan komoditi pangan berasal dari bahan hewani yang sangat sulit ditelusuri kehalalannya karena asal muasal hewan tidak nampak secara fisik. Pembuatan gelatin juga melewati beberapa proses yang menimbulkan komponen pada gelatin tidak dapat dianalisis untuk mengetahui sumber asalnya. Autentikasi halal menjadi salah satu cara menghilangkan kekhawatiran masyarakat dalam status kehalalan gelatin yang beredar. Berbagai metode telah dikembangkan dalam eksplorasi pembeda komponen halal dan non-halal namun masih memiliki kelemahan diantaranya kesulitan mendeteksi protein yang terdenaturasi, proses analisis degan waktu yang cukup lama, membutuhkan instrumen yang sangat canggih, biaya yang tak terjangkau dan spesifitas yang rendah. Setiap gelatin memiliki aroma khas yang disebabkan oleh perbedaan komponen asam amino penyusun gelatin yang identik dengan bahan bakunya sehingga senyawa volatil berpotensi menjadi senyawa penanda pada gelatin. Penelitian ini bertujuan membandingkan profil senyawa volatil gelatin yang terbuat dari berbagai ikan dan gelatin babi menggunakan metode ekstraksi mikro fase padat-kromatografi gas-spektrometri massa (SPME/GC-MS) dan analisis data multivariat. Hasil penelitian menunjukkan bahwa metode kombinasi SPME dan GC-MS terbukti dapat mengklasifikasikan gelatin sesuai dengan profil senyawa volatilnya. Senyawa penanda yang paling berpengaruh pada kelompok gelatin ikan adalah hexadecane, sedangkan pada kelompok gelatin babi adalah decane. Keduanya berasal dari golongan hidrokarbon dan belum pernah dilaporkan pada penelitian sebelumnya terkait analisis gelatin. Namun, hexadecane pernah dilaporkan sebagai senyawa volatil dengan konsentrasi tertinggi pada daging babi, sedangkan decane dilaporkan sebagai senyawa volatil yang ada pada daging ikan., Gelatin is a food additive derived mainly from animal which halal status difficult to trace because the origin of animal is not visible. Gelatin also through several processes that make components can’t be analyzed to determine gelatin’s source. Various methods have been developed in the exploration of gelatins differentiation from various sources. There are several limitations, including difficulty in detecting denaturated proteins, long time analysis process, expensive, sophisticated instruments, and low specificity. Each gelatin has a typical aroma due to differences in the amino acid components which are identical to the raw material, so that volatile compounds have the potential to be marker compounds in gelatin. This study aims to compare the profile of volatile compounds of gelatin made from various fish and pork gelatin using solid phase micro-extraction method-gas chromatography-mass spectrometry (SPME/GC-MS) and multivariate data analysis. The results showed that the SPME and GC-MS combination method was proven to be able to classify gelatin according to the profile of its volatile compounds. The most influential marker compound in the fish gelatin group was hexadecane, while in the pork gelatin group it was decane. Both are derived from the hydrocarbon group and have not been reported in previous studies related to gelatin analysis. However, hexadecane has been reported as a volatile compound with the highest concentration in pork, while decane has been reported as a volatile compound in fish meat.
Keyword: Authentication, GC-MS, gelatin, SPME, volatile

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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