Judul: Pengaruh modifikasi Heat Moisture Treatment (HMT) dengan radiasi microwave terhadap karakteristik fisikokimia dan fungsional tapioka dan maizena
Abstrak: Indonesia memiliki keanekaragaman potensi sumber daya alam seperti singkong dan jagung. Hasil ekstraksi dari kedua tanaman berupa pati telah banyak digunakan di berbagai kepeluan industri baik pangan maupun non pangan. Kedua pati tersebut memiliki keunggulan ketersediaan yang kontinu serta harga yang kompetitif khususnya pada tapioka. Akan tetapi ketika diaplikasikan untuk keperluan industri, kedua pati sring kali dijumpai masalah yang disebabkan keterbatasan sifat fungsionalnya yaitu ketidakstabilan oleh pengaruh mekanis, pemanasan, dan kondisi asam, kerusakan yang dipicu maupun yang disebabkan oleh retrogradasi. Modifikasi secara fisik yaitu heat moisture treatment (HMT) dipilih untuk memperbaiki sifat fungsional tersebut dikarenakan proses yang dilakukan dapat menghasilkan pati yang lebih aman dan „alami‟. Modifikasi HMT dilakukan menggunakan radiasi microwave. Untuk mendukung aplikasinya pada proses modifikasi HMT, perlu diketahui pengaruh radiasi microwave pada tapioka dan maizena terhadap karakteristik fisikokimia dan fungsional pati termodifikasi yang dihasilkan.
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Judul: Pengaruh Heat Moisture Treatment terhadap Sifat tekstural dan Retrogradasi Gel Pati Aren dan Tapioka
Abstrak: Heat Moisture Treatment (HMT) is one of physical modification techniques that uses limited moisture where heating process at high temperature is implemented for certain period of time. This research studied the effect of HMT modification on textural properties and retrogradation of aren and tapioca starch gel. HMT modification was done by using autoclaving method at 120 oC in 60 minutes for tapioca and 90 minutes for aren. Before autoclaving process, the water content of starch was adjusted into 20% (b/b, wb). The observation of retrogradation was done on starch gel with water content 10% (b/b, db) and refrigerated at 4 oC for 7 days. Textural analysis was done by doing compression using texture analyzer. Degree of retrogradation analysis was done by analyzing the changes of hardness from starch gel, and analyzing amylose hydrolisis using α-amylase enzyme. The result from textural analysis and degree of retrogradation analysis show that HMT modification could make starch gel become fragile, shown by decreasing breaking strain. From degree of retrogradation analysis, it is known that HMT modification increased hardness and degree of retrogradation of starch gel. According to this research, it can be concluded that HMT modification could make starch gel become fragile, increase hardness, and increase retrogradation of native starch gel.
Keyword: textural properties., retrogradation, heat moisture treatment

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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