PHYSICOCHEMICAL CHARACTERISTICS OF SAGO STARCH OBTAINED FROM FLUIDIZED BED DRYING USING SOLAR AND BIOMASS POWERED CROSS FLOW FLUIDIZED BED DRYER. The research aim is to study the comparative quality of sago starch drying results using cross flow fluidized bed dryer powered by solar and biomass in conventional drying, particularly the chemical composition and physicochemical characteristics. This research was conducted through a drying phase of wet sago starch using a cross flow fluidized bed dryer, and drying in conventional as well as dried sago starch quality testing results are drying. The results of this study indicate that dry sago starch which has been drained by means of cross flow fluidized bed dryer has a chemical composition that does not vary much with starch which is dried by conventional drying, so that the dried sago starch produced by the dryer is very good. On the other hand the use of dryers is the more correct because the physicochemical properties of sago starch using a low drying temperature and drying time is short. Tujuan penelitian ini adalah mempelajari perbandingan kualitas pati sagu hasil pengeringan menggunakan alat pengering cross flow fluidized bed bertenaga surya dan biomassa dengan pengeringan secara konvensional, khususnya komposisi kimia dan karakteristik fisikokimia. Penelitian ini dilakukan melalui beberapa tahapan yaitu pengeringan pati sagu basah menggunakan alat pengering cross flow fluidized bed, pengeringan secara konvensional serta pengujian kualitas pati sagu kering hasil pengeringan. Hasil dari penelitian ini menunjukkan bahwa pati sagu kering yang telah dikeringkan dengan alat pengering cross flow fluidized bed memiliki komposisi kimia yang tidak berbeda jauh dengan pati yang dikeringkan dengan cara pengeringan secara konvensional, sehingga pati sagu kering yang dihasilkan oleh alat pengering tersebut sangat baik. Di sisi lain penggunaan alat pengering ini semakin memperbaiki sifat fisikokimia pati sagu sebab menggunakan suhu pengeringan yang rendah dan waktu pengeringan yang singkat.   Kata Kunci: pengering unggun terfluidakan; fisikokimia; pati sagu

<em>The aim of this research was to evaluate the chemical composition of tubers and cassava starch and cassava starch physical Masni District. This study consists of three (3) stages: preparation of materials and chemical characterization of fresh tubers, starch extraction and chemical and physical characterization of cassava. Extraction is done by using a 3:1 ratio of water and tubers. The results showed that the starch content of the fresh tubers ranged from 13.12% to 46.09% while the starch content of cassava starch between 81.40% to 89.55%. Amylose starch levels ranged from 12.28% to 27.38% while the amylopectin content ranged from 72.61% to 87.71%. Starch granule shape is round, round cut, elliptical with a size ranging between 5-25 ?m, the temperature ranges from 65-69^oC gelatinization and power development starches ranged from 1.42 to 26.65.</em>

Pneumatic Conveying Recirculated Dryer (PCRD) is one of many driers used for drying wet sago starch. The most important components of this PCRD machine are the vertical pipe and the u-bend. The vertical pipe and the u-bend are the primary drying spaces. They must have a good temperature distribution and air velocity dryer. To observe the process of temperature distribution and the air velocity dryer in the vertical pipe and u-bend, Computational Fluid Dynamics (CFD) analysis is required. The research was aimed to analyze the temperature distribution and the air velocity dryer flow in the recirculated pipe of PCRD machine by using CFD analysis. The analysis was based on the variance of the temperature, the air velocity, and the height of the vertical pipe in PCRD machine. The analysis was conducted using Ansys Workbench Fluid Flow ver. 15. This software was used to simulate the temperature and the air flow velocity in the vertical pipe and the u-bend. However, the flow characteristics and patterns of the wet sago starch were not included in the discussion. The turbulence model used in the simulation was the Reynold Stress Models (RSM). The result of the simulation showed that the temperature along the vertical pipe and the u-bend was distributed evenly. The error value between the result of the simulation and the observation was low (0.10–2.04%). The average test value with paired t-test showed that the simulation and observation result was not significantly different. This results indicated that the simulation fit well with the observation value or the real condition in the PCRD machine. The distribution of the temperature and the air velocity dryer in the vertical pipe and the u-bend were able to reduce the moisture content on sago starch from 31% (wb) to 9% (wb). Therefore, the vertical pipe and the u-bend design was appropriate to use in PCRD machine for drying wet sago starch.

Recirculation drying process ofmaterial on pneumatic conveying recirculated dryer (PCRD)are ABSTRAKProses pengeringan bahan secara resirkulasi pada pneumatic conveying recirculated dryer (PCRD) sangat rumit dan tidak linier, sehingga sulit untuk memprediksi kadar air akhir bahan sesuai dengan yang disyaratkan. Tujuan penelitian ini adalah mengembangkan model jaringan syaraf tiruan (JST) untuk memprediksi kadar air akhir bahan pada mesin PCRD. Pada penelitian ini telah dirancang mesin PCRD dengan variasi variabel secara resirkulasi dan aplikasi Graphical User Interface (GUI) JST menggunakan software Neural Network Toolbox pada software komputer. Model JST dirancang menggunakan struktur jaringan yang terdiri dari 11 neuron input, hidden multilayer, dan satu neuron output dengan algoritma pembelajaran backpropagation. Pelatihan dan pengujian model menggunakan data observasi masing-masing sebanyak 54 dan 27 set data. Uji validitas model memperoleh nilai r 2 latih sebesar 0,99 atau 99%, dan r 2 uji sebesar 0,96 atau 96%. Hal ini menunjukkan bahwa model sangat valid digunakan untuk memprediksi kadar air akhir bahan pada mesin PCRD. Optimasi model JST pada proses pelatihan mempunyai nilai RMSE sebesar 0,118% wb, MAE 0,056% wb dan MRE 0,644%. Nilai optimasi model JST pada proses pengujian adalah RMSE sebesar 0,226% wb, MAE 0,129% wb dan MRE 1,496%.Kata kunci: prediksi, kadar air, model, pneumatic conveying recirculated dryer, jaringan syaraf tiruan PENDAHULUANPneumatic conveying recirculated dryer (PCRD) adalah pengembangan dari pneumatic conveying dryer (PCD) atau flash dryer dan umumnya digunakan pada industri pengeringan bahan-bahan tepung. Mesin PCRD pada umumnya dilengkapi unit penggilingan (milling) dan resirkulasi bahan (manifold). Waktu tinggal bahan pada mesin PCRD adalah 30-300 detik (Cristiansen dan Sardo, 2001;Frosterud et al., 2011). Pada penelitian ini telah dikembangkan mesin PCRD dengan merancang manifold berbentuk siklon resirkulasi yang dilengkapi blower sentrifugal untuk meresirkulasi dan memisahkan bahan basah dengan kering. Siklon resirkulasi bahan tersebut, dihubungkan secara seri dengan siklon output bahan. Pemisahan bahan basah dan kering pada siklon resirkulasi sangat menentukan tingkat kadar air akhir bahan yang dihasilkan selama proses pengeringan. Kadar air akhir bahan adalah salah satu parameter untuk menentukan keberhasilan proses pengeringan.

Native Sago starch is difficult to be used in industry because of the limitations of its properties. The aim of this research was to study effect of UV-C photo-oxidation on chemical properties and baking expansion of sago starch. Five slurry ratio (starch : water ratio): 1:2; 1:4; 1:6; 1:8; and 1:10 were oxidized with UV-C irradiation for 20 minutes, and then compared with native sago starch. The results showed that UV-C photooxidation increased amylose content and paste viscosity, but decreased swelling power and solubility, and carbonyl and carboxyl content. Used of UV-C as a photooxidator was effective in increasing baking expansion characteristic, and the best slurry ratio was 1:6, which has 6.97 ml/g specific volume or 33.7% higher than that of native sago starch (5.22 ml/g)