Judul: Pengaruh Sifat Fisikokimia RBDPO (Refined Bleached Deodorized Palm Oil) terhadap Karakteristik dan Stabilitas Margarin
Abstrak: Salah satu produk pangan hasil olahan dari minyak sawit yang telah banyak dikomersialisasikan adalah margarin. Bahan baku utama pembuatan margarin adalah minyak sawit yang telah mengalami pemurnian atau Refined Bleached Deodorized Palm Oil (RBDPO). Perbedaan sumber RBDPO yang digunakan dalam pembuatan margarin, dapat menyebabkan karakteristik margarin yang dihasilkan berbeda dan berpengaruh terhadap stabilitas karakteristik margarin selama penyimpanan. Faktor yang diduga memengaruhi karakteristik dan stabilitas margarin selama penyimpanan adalah sifat fisikokimia RBDPO. Oleh karena itu, perlu dilakukan kajian pengaruh dari parameter mutu RBDPO yang termasuk di dalamnya analisis kadar MAG, DAG, dan TAG terhadap karakteristik margarin yang dihasilkan. Penelitian ini menggunakan sembilan sampel RBDPO yang berasal dari tiga pabrik pengolahan minyak sawit di Indonesia. Pembuatan margarin dilakukan pada skala pilot plant, dilanjutkan dengan pengujian terhadap sampel margarin yang dihasilkan dan uji stabilitasnya selama penyimpanan. Hasil penelitian menunjukkan bahwa sembilan sampel RBDPO yang dianalisis mempunyai karakteristik mutu yang cukup beragam. Tiga sampel yang mewakili ketiga pabrik pengolahan RBDPO dan dengan karakteristik yang berbeda diolah lebih lanjut menjadi margarin. Sampel-sampel tersebut adalah sampel RBDPO J4 yang berasal dari pabrik di Jakarta, RBDPO M3 dari pabrik di Medan, dan RBDPO S1 dari pabrik di Surabaya. Margarin yang berbahan baku RBDPO J4 memiliki persentase SFC, TAG, serta nilai firmness dan plasticity yang lebih tinggi jika dibandingkan dengan margarin yang dihaslkan dari RBDPO M3 dan RBDPO S1. Margarin-margarin tersebut selanjutnya disimpan untuk dianalisis stabilitas karakteristiknya. Selama penyimpanan 37 hari di dalam inkubator bersuhu 30 oC, 35 oC, dan 40 oC, ketiga sampel margarin mengalami perubahan karakteristik warna, plasticity, firmness, dan oiling out. Margarin J4 dengan kadar TAG tertinggi menunjukkan kestabilan terhadap panas yang lebih baik daripada margarin M3 dan margarin S1 ditunjukkan dari lambatnya perubahan karakteristiknya selama penyimpanan. Margarin dengan kadar TAG lebih tinggi juga memiliki tekstur yang lebih firm dan plastic. Berdasarkan penelitian ini, diketahui bahwa dengan persentase TAG yang lebih tinggi dan persentase DAG lebih rendah, margarin yang dihasilkan memiliki stabilitas penyimpanan dan stabilitas panas yang lebih baik, serta karakteristik sensori seperti warna, plasticity, oiling out, dan firmness yang juga lebih baik. TAG yang rendah dan DAG yang tinggi menyebabkan margarin lebih mudah mengalami penurunan kualitas selama penyimpanan.
Keyword: DAG, MAG, margarine, palm oil, RBDPO, TAG

Judul: Pengaruh sifat fisikokimia RBDPO (refined bleached deodorized palm oil) terhadap karakteristik dan stabilitas margarin
Abstrak: Margarine is a food product processed from palm oil that has been commercialized. The main raw material for margarine is palm oil that has been purified or Refined Bleached Deodorized Palm Oil (RBDPO). The different characteristics of RBDPO that is used for making margarine cause different characteristics of margarine and also influence margarine stability during the storage. Determining factors that affect the characteristics and margarine stability during the storage period are the physicochemical properties of RBDPO. Therefore, it is necessary to perform quality analysis of RBDPO including the analysis of MAG, DAG, and TAG percentage to determine its effect to margarine characteristics. This study used nine samples of RBDPO from three different palm oil processing plants in Indonesia. The margarine processing was implemented on pilot plant scale, followed by margarine physicochemical and stability analysis during the storage time. The result of the study showed that nine samples of RBDPO had some varieties in their quality characteristics. Three of nine samples selected because they represent three palm oil processing plant that have different characteristics. The samples were labelled as RBDPO J4 from Jakarta, RBDPO M3 from Medan, and RBDPO S1 from Surabaya. Margarine which made from RBDPO J4 had higher percentage of SFC and TAG, and also higher value of firmness and plasticity than margarine that made from RBDPO M3 dan RBDPO S1. The margarines and then were stored for analysis of their stability. During 37 days of storage in incubator with temperature of 30 oC, 35 oC, and 40 oC, the color, plasticity, firmness, and oiling out characteristics of three margarine were changed. Margarine J4 which contains the highest percentage of TAG had better heat stability than margarine M3 and margarine S1 that is indicated by the slow changed of its characteristics during the storage. Margarine with the highest TAG percentage also had more plastic and firm texture. According to this study, higher TAG percentage and lower DAG precentage will make the margarine sustain better stability and sensory characteristics. Lower TAG percentage and higher DAG percentage causes margarine qualities to degrade easier during storage.
Keyword: Bogor Agricultural University (IPB), TAG, RBDPO, palm oil, margarine, MAG, DAG

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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