Abstract

The demand of powdered food products such as soups, sauces, dried yeasts and herbal medicine is increasing for consumer convenience. Mostly, these products have been produced with drying process either, direct sunlight, conventional, or modern dryer. The direct sunlight dryer depends on the daily weather both in the product quality and process continuity. Meanwhile, conventional dryer results high energy consumption as well as low product quality due to the introduction of hot air. In addition, modern dryer process can improve the product quality, but the energy efficiency was fair. This study discusses the design and application of adsorption dryer with zeolite for food product. As samples, the carrageenan isolated from seawed and roselle extract were dried. Here, the air as drying medium was dehumidified by zeolite to enhance the driving force at lower temperature. The study was conducted in various air velocity, temperature and relative humidity. Results showed that the air temperature had the most superior effect both on product quality and drying rate. The higher temperature, the higher drying rate but the lower product quality. Air dehumidification had a positive effect on product quality and drying for low operational temperature. For all cases, it was recommended that the drying around70°C or below was favorable for reasonable quality and drying rate.

Keywords:

Carrageenan, dehumidification, roselle, sensitive, zeolite,

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Competing interests

The authors have no competing interests.

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