Judul: Clove oil encapsulated by tapioka (Manihot esculenta) and gum Arabica and prediction of it shelflife
Abstrak: This experiment was aimed to study about characteristic of tapioca and gum Arabica as an encapsulant agent and prediction its shelf life. Beside the result of this experiment able to give alternative source of raw material in encapsulant agent matter. Unlike other starch sources, such as corn, rice and wheat, tapioca roots contain high starch content and a very low quantity of impurities. Tapioca is an excellent material for starch production with respect to its availability, raw material cost and ease of starch extraction. The micro encapsulation is generally performed by forming a polymeric matrix around particular compounds to protect its biological activity and enhance physical chemical stability. Arabic gum have been encapsulating agent for many years, but the source was a bit difficult to find and quite expensive. The step of this research was divided into two parts. The first part is to observe characteristic of encapsulation clove oil from several parameters such as moisture content, bulk density, solubility, percentage of yield, free flowing and organoleptic test. Various percentages of tapioca and gum Arabic was conducted and based on evaluation from those parameters then composition appointed to be determined shelf life by sorpsi isotherms curve method. Based on experiment, it was concluded that percentage appointed for the next experiment was tapioca: gum arabica with composition 50 : 50 % is the best combination. Based on further experiment, we obtained result for moisture content is 3.79%, balance water content is 17.55 % and critical water content is 11.76 %. All value obtained, calculated by Labuza formulation so we can determine of shelf life with aluminum foil bag and HDPE as packaging material. The result was 25.56 months for aluminum foil bag and 3.40 months for HDPE packaging.
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Judul: Estimation of the Shelf Life of Cocoa Powder with Water Isothermic Sorption Approach
Abstrak: Produk pangan berbentuk bubuk, seperti bubuk kakao memiliki karakteristik yaitu mudah menyerap air atau bersifat higroskopis. Sehingga dalam penyimpanannya perlu menggunakan kemasan yang memiliki kemampuan untuk menahan uap air yang baik. Tujuan penelitian ini adalah menentukan model kurva sorpsi isotermis pada produk bubuk kakao dan menduga umur simpan bubuk kakao pada kemasan standing pouch aluminium foil dan kraft dengan pendekatan sorpsi isotermis air. Penelitian ini diawali dengan pembuatan sampel bubuk kakao. Kemudian, dilakukan penentuan kadar air awal, kadar air kritis, kadar air kesetimbangan, penentuan kurva sorpsi isotermis, penentuan model persamaan sorpsi isotermis, penentuan slope, penentuan permeabilitas uap air kemasan. Lalu, dilanjutkan dengan perhitungan bobot padatan per kemasan dan luas permukaan kemasan. Tahap terakhir adalah perhitungan umur simpan menggunakan pendekatan sorpsi isotermis air. Hasil penelitian menunjukkan bahwa model persamaan kurva sorpsi isotermis yang tepat untuk menggambarkan fenomena sorpsi isotermis produk bubuk kakao adalah model Hasley dengan nilai Mean Relative Determination (MRD) paling kecil yaitu 2,007. Umur simpan pada kondisi penyimpanan suhu 30°C dan kelembaban relatif (RH) 75% dan 80% dengan kemasan standing pouch aluminium foil berturut-turut selama 665 hari dan 514 hari serta dengan kemasan standing pouch kraft selama 293 hari dan 227 hari., Food products in the form of powders, such as cocoa powder have characteristics that easily absorb water or are hygroscopic. So that in storage, it is necessary to use packaging that can hold good moisture. This study aimed to determine the isothermic absorption curve model for cocoa powder products and calculate the shelf life of cocoa powder on the packaging standing pouch aluminum foil and kraft with water isothermic sorption approach. This research begins with making cocoa powder samples. Then, determine the initial water content, critical water content, equilibrium water content, and isothermic sorption curve, select the isothermic sorption equation model, determine the slope, determination of the water vapor permeability of the packaging. Then, calculate the weight of solids per package and the package’s surface area. The final step is estimating the shelf life using the isothermal sorption approach. The results showed that the correct isothermic sorption curve equation model to describe the isothermic sorption phenomenon of cocoa powder products was the Hasley model with the smallest Mean Relative Determination (MRD) value of 2,007. Shelf life at storage temperature conditions of 30°C and relative humidity (RH) 75% and 80% with packaging standing pouch aluminum foil consecutively for 665 days and 514 days and with packaging standing pouch kraft for 293 days and 227 days.
Keyword: aluminum foil, cocoa powder, Hasley, kraft, water isothermic sorption

Judul: Pemanenan Energi Listrik dari Kincir Angin Vertikal
Abstrak: Usaha pemanenan energi angin di Indonesia masih sedikit. Sampai Tahun 2016 hanya 3.54 MW alat pemanenan energi angin yang sudah terpasang. Kendala utamanya ialah dibutuhkan investasi yang besar untuk membuatnya. Pembuatan kincir angin dengan ukuran yang lebih kecil dengan bahan yang dapat dibeli di pasar lokal menjadi solusi agar pembuatan kincir angin lebih ekonomis. Pembuatan kincir vertikal tipe Savonius dapat menjadi solusinya. Kincir vertikal Savonius dapat beroperasi pada kecepatan < 3 m/s dan ketinggian < 50 m. Kincir angin ini terdiri dari tiga sistem, yaitu generator, rotor kincir dan transmisi pulley-belt. Generator dibuat dari modifikasi motor AC dan magnet neodymium. Rotor kincir dibuat dari pipa PVC 4”, pipa alumunium ¾”, dan papan polikarbonat. Transmisi pulley-belt dibuat dari plastik dan karet. Kincir ini membutuhkan gaya minimal 3 N untuk dapat berputar atau torsi minimalnya 0.75 Nm. Kecepatan angin yang dibutuhkan untuk merotasikannya sebesar 1.9 m/s. Daya maksimal yang dapat dihasilkan ialah 5.76 watt berupa tegangan sebesar 36 volt dan arus 160 mA.
Keyword: energi terbarukan, generator, motor AC, sudu Savonius