Judul: Identification of Distinguishing Indicators of Natural Formaldehyde Based on Parameters of Quality Deterioration Value in Freshwater Fish
Abstrak: Ikan nila, mas, dan patin merupakan ikan air tawar komersil dan dagingnya menjadi komoditas ekspor dalam bentuk segar atau dingin dan beku. Formalin menjadi salah satu bahan berbahaya yang penggunaannya sering disalahgunakan sebagai pengawet pada ikan untuk mencegah kerusakan ikan. Formaldehida dapat terbentuk secara alami pada ikan selama proses kemunduran mutu ikan melalui reaksi reduksi trimetilamin oksida (TMAO) yang terjadi secara enzimatik dengan hasil samping berupa dimetilamin (DMA). Penelitian ini bertujuan menentukan indikator pembeda dengan penambahan formalin dan tanpa penambahan formalin pada ikan nila, mas, dan patin selama 8 minggu dengan penyimpanan beku. Parameter yang diamati adalah morfometrik, organoleptik, pH, total volatile base (TVB), formaldehida (FA), dan dimetilamin (DMA). Parameter FA dan TVB dapat dijadikan sebagai indikator pembeda antara kedua perlakuan tersebut. Parameter mata juga dapat dijadikan sebagai indikator pembeda, akan tetapi bukan merupakan parameter yang kuat., Tilapia, carp, and pangas catfish are commercial freshwater fish and their meat is an export commodity in fresh or chilled and frozen form. Formalin is one of the hazardous materials whose use is often misused as a preservative in fish to prevent fish damage. Formaldehyde can be formed naturally in fish during the process of deterioration of fish quality through the reduction reaction of trimethylamine oxide (TMAO) which occurs enzymatically with by-products in the form of dimethylamine (DMA). This study aims to determine the differentiating indicators with and without the addition of formalin in tilapia, carp, and catfish for 8 weeks with frozen storage. Parameters observed were morphometric, organoleptic, pH, total volatile base (TVB), formaldehyde (FA), and dimethylamine (DMA). The the parameters FA and TVB can be used as indicators of the difference between the two treatments. The eye parameter can also be used as a indicator, but it is not a strong parameter.
Keyword: carp, natural formaldehyde, nile tilapia, pangas catfish, quality deterioration

Judul: Identification Of Differentiating Indicators Of Formaldehyde Origin Based On Parameters Of Quality Deterioration Value In Tuna, Mackerel and Yellowtail.
Abstrak: Keamanan pangan merupakan suatu hal yang perlu diperhatikan dalam membangun sektor perikanan. Penyalahgunaan formalin sebagai bahan pengawet ikan merupakan salah satu permasalahan yang kerap ditemukan di Indonesia. Akan tetapi, secara alami ikan dapat membentuk senyawa formaldehida melalui reaksi trimetilamin oksida (TMAO). Hal ini menyebabkan sulitnya membedakan ikan dengan dan tanpa penambahan formaldehida. Penelitian ini bertujuan mengindentifikasi indikator pembeda berdasarkan parameter laju kemunduran mutu (organoleptik, nilai pH, TVB, FA, dan DMA) pada ikan tongkol, ekor kuning dan kembung dengan penambahan dan tanpa penambahan formalin selama 8 minggu dalam penyimpanan beku. Indikasi ikan yang mengandung formalin selama masa penyimpanan yaitu tingginya kandungan formaldehida serta DMA seiring dengan lama penyimpanan. Parameter organoleptik pada penelitian ini belum dapat dijadikan sebagai parameter pembeda yang kuat, The development of the fishing industry must take food safety into account. Formalin misused is one of the problems that is often found in Indonesia. However, fish are naturally able to form formaldehyde compounds through the reaction of trimethylamine oxide (TMAO). As a result, it becomes challenging to distinguish between fish possessing endogenous formaldehyde content and fish containing formalin during storage. This study aims to identify differentiating indicators with and without the addition of formaldehyde in tuna, mackerel, and yellowtail based on quality rating rate parameters (organoleptic, pH value, TVB, formaldehyde, and DMA) for 8 weeks with frozen storage. Indications of fish containing formalin during storage are high levels of total formaldehyde and DMA. Organoleptic parameters in this study could not be used as strong differentiating parameters.
Keyword: formaldehida, ikan, indikator, suhu beku

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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