Judul: Shelf life determination of sweet potato chips and taro chips in plastic and aluminium foil packaging
Abstrak: Mentawai island has great potensial on producing sweet potato and taro. The huge number of the production must be balanced by proper-harvest handling. The handling method is by making the comodities as chips by vaccum frying and then will be packed using plastic and aluminium foil packaging. This research is to determine shelf life of sweet potato chips and taro chips and to decide what kind of the best packaging. Shelf life was determined by using acceleration method with Arrhenius equation. Critical parameter for determining the shelf life was flavour. The shelf life of sweet potato chips at room temperature (25oC) was 155 days using aluminium foil, 117 days using PP, and 37 days using HDPE. Whereas storing life of taro chips was 287 days using aluminium foil, 60 days using PP, and 56 days using HDPE. The best packaging for sweet potato chips and taro chips are aluminium foil.
Keyword: shelf life, packaging, taro chips, sweet potato chips

Judul: Pendugaan Umur Simpan Keripik Wortel (Daucus carota L.) Dalam Kemasan Alumunium Foil Dengan Metode Akselerasi
Abstrak: The utilization of fresh carrots into carrot crisps is an attempt to handle the short shelf life and increase the added value of carrots. The aims of this research were to determine the critical quality parameter of carrot chips in alumunium foil packaging material during storage and to estimate the shelf life of carrot chips in alumunium foil packaging material with acceleration method. There are two factors of the packaging and storage treatments that applied to carrot chips : (1) carrot chips packaged with aluminum foil packaging material with 3 (three) levels of thickness, there are 50μm, 80μm, and 100μm; and then (2) carrot chips that have been packaged then stored in 3 (three) different storage temperatures, thera are in the storage temperature (30°C) and in the incubator which have temperature at 37oC and 45oC. The quality parameter that have been tested to estimated the product’s shelf life were moisture content, crispness, and free fatty acid content. The critical point was conducted in hedonic test on panelist, the point as follows; critical moisture content (6,55%), critical crispness (3,42 kgf), and the critical free fatty acid (0,99%). Based on Arrhenius method, the free fatty acid content is the most critical parameter during the storage. The Arrhenius model to estimate shelf life of carrot chips on the alumunium foil which has thicknnes 50μm is ln k = -3351,5069(1/T) + 6,7356 (R2 = 0,9988), on the alumunium foil 80μm is ln k = -2318,5866(1/T) + 3,2215 (R2 = 0,9182), and on the alumunium foil 100μm is ln k = -2264,1985(1/T) + 2,9730 (R2 = 0,9320). The quality decrease rate (k) free fatty acid content of carrot chips at storage temperature (25oC) on alumunium foil which has thicknnes 50μm is 0,0110% per day, on the alumunium foil 80μm is 0,0105% per day, and on the alumunium foil 100μm is 0,0098% per day. The carrot chips shelf life based on that critical parameter (at the storage temperature 25oC) is 76 days for carrot chips in alumunium foil which has thickness 50μm, 80 days for carrot chips in alumunium foil which has thickness 80μm, and 85 days for carrot chips in alumunium foil which has thickness 100μm. The carrot chips in alumunium foil which has thickness 100μm has the longest shelf life than alumunium foil which has thickness 50μm dan 80μm. Alumunium foil which has thickness 100μm during storage of carrot chips can increase more protection, hold out the odor, increase the product maintaining by water vapour and gas, couldn’t pass by light, and to obstruct penetrating of oxygen.
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Judul: Analisis kestabilan model penyebaran gonorrheae
Abstrak: Gonorrheae merupakan sejenis penyakit kelamin yang disebabkan oleh bakteri gonococcus yang menyebar melalui hubungan seksua!. Penderita 'penyakit ini umumnya para pekerja seks alau mereka yang melakukan seks tak wajar. Penyakit ini memiliki karakteristik unik yang mendasar yakni tidak ada kekebalan, artinya bahwa bila penderita yang dinyatakan sembuh kemungkinan untuk terjangkit sangat besar dan setiap individu yang rentan akan terinfeksi jika berhubungan seksual dengan penderila penyakit Inl. Martin Braun (1975) membuat suatu model epidemik tentang penyebaran penyakit gonorrheae. Pemodelan ini hanya membahas penyebaran gonorrheae yang disebabkan oleh hubungan seksual lawan jenis (heteroseksual).
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