Improvised filter unit for agar extraction/filtration

Abstract

Agar is a high-priced phycocolloid usually extracted from red seaweeds (Rhodophyta). It has many uses in the food and pharmaceutical industry (Chapman 1970, Armisen and Galatas 1987). Worldwide production of agar has reached 5000t and the demand is still increasing because of new applications (Santelices and Doty 1989). In laboratory-scale extraction of agar the filtration system preferred is a stainless steel pressure filter (Aguilar-Santos and Doty 1978, Hoyle 1978). Commercial-scale extraction, however, uses filter presses of varying designs, each according to the particular need (Armisen and Galatas 1987). In small laboratories with limited facilities, an improvised extraction/filtration unit can be devised for routine laboratory work on agar processing. In the course of extraction/filtration trials conducted at SEAFDEC/AQD, a simple but efficient extraction/filtration unit was designed. It took into consideration the volume of the sample, the temperature during extraction, and the ease of using the unit.