Drying is a significant step in the production of carrageenan. However, current drying process still deals with too long drying time and carrageenan quality degradation. The foam mat drying is an option to speed up drying process as well as retaining carrageenan quality. In this case, the carrageenan was mixed with egg white (albumin) as foaming agent and methyl cellulose for foam stabilizer. The foam will break the carrageenan gels and creates the porous structure resulting higher surface area for water transfer. This research studied the effect of egg white and methyl cellulose on carrageenan drying at various air temperature, and thickness. As a response, the water content versus time was observed and the drying rate was estimated. Meanwhile, the carrageenan texture was verified by X-RD (X-Ray Diffraction) and TEM (Transmission Electron Microscopy). Results showed that the presence of egg white stablized by methyl cellulose can speed up drying rate as well as retaining the crystalline structure of carrageenan. The higher albumin content, the faster drying rate. However, the addition of albumin and methyl cellulose restricted not more than 30 % in the mixture for keeping carrageenan quality and purity. By adding egg white 20 % and methyl cellulose 10 %, the water diffusion and drying rate can be two fold compared with carrageenan drying without foam. The improvement can be higher at the higher temperature and thinner carrageenan sheets.

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The seaweeds are the important commodities as raw material for food or additives. One of the popular seaweeds, Eucheuma cottonii, contains carrageenan for starch or fiber sources that can be applied for beverages or gelatin. Currently, the seaweed has been widely provided as dry product in order to minimize the cost for transportation as well as prolong storage life. However , current drying process still deals with energy in-efficiency and product quality degradation. The dehumidified air can be an option to retain the seaweed quality. With lower humidity, the driving force for drying can be improved in which shortened drying time. This research aimed to study the effect of air temperature, humidity, and velocity on seaweed drying. For supporting the study, the several drying kinetic models were developed to predict drying rate. Furthermore, the seaweed quality was evaluated based on rehydration ratio. Results showed that for all cases, drying at 70 o C or below can provide reasonable drying time. The higher air temperature and air flow, the faster drying time. Meanwhile, the dehumidified air also affected drying t ime positively. In addition, the model based on Page is the best option to estimate the drying rate. For all drying condition, the rehydration ratio of dry seaweed was close to the initial wet condition. This implied that the dry seaweed was very suitable for food.

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Applying dehumidified air is considered as an option to retain quality in carrageenan drying. This work concerns the effects of operational temperature, air velocity, and carrageenan thickness on the progress of drying and product quality when using dehumidified air. Final product quality and progress of drying were measured by experiments, and a two dimensional model was developed to analyze progress of drying for the different operational conditions. The experimental and modeling results showed that air dehumidification with zeolite reduces the drying time the most at low temperatures. Under these conditions the carrageenan qualities whiteness and gel strength are the least affected by the exposure to the drying temperature. The drying time is the shortest at 120°C, but at this temperature the carrageenan quality degrades the most and is not be improved by air dehumidification. Moreover, the quality is improved by increasing the air velocity and by drying thin carrageenan sheets.

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ACTIVATION OF NATURAL ZEOLITE AS AN ADSORBENT FOR LOW TEMPERATURE DRYING SYSTEM. Drying is one process which is used in many industries, especially in food product. The process usually still has low energy efficiency and can make food deterioration because of the usage of high temperature. One alternative in drying technology is the use of zeolite as a water vapor adsorbent. This kind of drying method make it possible to operate in lower temperature, hence it will be suitable for heat sensitive product. Natural zeolit can be one promising adsorbent since it is spreadly abundant in Indonesia. Natural zeolite must be activated first before used, in order to get zeolite with high adsorption capacity. Activation process in natural zeolite will change the Si/Al ratio, polarity, and affinity of zeolite toward water vapor and also increase the porosity. Activation of natural zeolite can be done with two methods, chemical activation use NaOH and physical activation use heat. In the activation using NaOH, natural zeolite is immersed with NaOH solution 0.5-2N in 2 hour with temperature range 60-900C. The process is continued with the drying of zeolite in oven with 1100C for 4 hours. While in heat treatment, zeolit is heated into 200-5000C in furnace for 2-5 hours. SEM analysis is used to compare the change in zeolite morphology before and after each treatment, while to know the adsorption capacity of zeolite, the analyses were done in many temperature and relative humidity. Result gives the best condition in NaOH activation is NaOH 1N and temperature 700C, with water vapor loading is 0.171 gr/gr adsorbent. In heat treatment, the best condition is 3000C and 3 hours with loading 0.137 gr water vapor/gr adsorbent.  Pengeringan merupakan salah satu proses yang banyak digunakan pada produk pangan. Proses ini umumnya menyebabkan kerusakan pada bahan pangan, disamping masih rendahnya efisiensi energi. Salah satu alternatif pada proses pengeringan yaitu penggunaan zeolit sebagai adsorben uap air. Proses pengeringan dengan menggunakan zeolit sebagai adsorben ini memungkinkan operasi pengeringan dilakukan pada suhu rendah sehingga sesuai untuk bahan yang tidak tahan panas. Zeolit alam merupakan salah satu alternatif bahan adsorben. Akan tetapi zeolit ini harus diaktivasi terlebih dahulu untuk mendapatkan zeolit dengan kemampuan adsorpsi yang tinggi. Proses aktivasi pada zeolit akan merubah rasio Si/Al zeolit, polaritas serta afinitas zeolit terhadap air dan meningkatkan pori-pori zeolit Adsorpsi zeolit alam dilakukan dengan dua cara yaitu dengan NaOH dan dengan panas. Pada aktivasi dengan NaOH, zeolit dicampur dengan NaOH 0,5-2N selama 2 jam pada suhu 60-900C. Sementara pada aktivasi fisis, zeolit dipanaskan pada 200-5000C selama 2-5 jam. Untuk mengetahui perubahan struktur pori zeolit maka dilakukan analisa SEM dan untuk mengetahui kemampuan adsorpsi zeolit maka dilakukan analisa daya adsorpsi zeolit terhadap uap air pada berbagai suhu dan berbagai kelembaban relatif. Hasil menujukkan bahwa pada aktivasi dengan NaOH diperoleh kondisi aktivasi terbaik adalah NaOH 1N pada pemanasan 700C dengan daya adsorpsi 0,171 gr uap air/gr adsorben. Sementara untuk aktivasi dengan panas, kondisi aktivasi terbaik adalah pemanasan 3000C selama 3 jam dengan daya adsorpsi 0,137 gr uap air/gr adsorben.

Recently, the main problem of the rice stock and distribution in Indonesia is the quality degradation as indicated in unpleasant odor (smelly), stained, yellowness, and high percentage of broken rice. This is due to the low of paddy quality dried by from either direct