June 1990

ASEAN/SF/90/Manual No. 5 A MANUAL FOR THE PROCESSING OF AGAR FROM GRACILARIA by Gertrudes A. Santos, Ph.D. Seaweed Processing Consultant

ASEAN/UNDP/FAO Regional Small-Scale Coastal Fisheries Development Project
Manila, Philippines
1990

TABLE OF CONTENTS

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TABLE OF CONTENTS

1.   INTRODUCTION

1.1   Agar - historical background

1.2   Definition and description

1.3   Chemistry

1.4   Properties of agar gels

1.5   Properties of Gracilaria agars

2.   PROCESSING GRACILARIA FOR THE EXTRACTION OF AGAR

2.1   Sample collection

2.1.1   Recording the collection data

2.1.2   Mounting of a herbarium specimen

2.1.3   Cleaning of the sample

2.1.4   Drying of the sample

2.1.5   Transportation of the dry samples

2.2   Determination of quality of seaweed sample

2.3   Pre-extraction treatment

2.3.1   Bleaching

2.3.2   Bleaching with lime

2.3.3   Alkali treatment

2.4   Extraction of agar

2.5   Extraction of agarose

2.5.1   Extraction of agarose from Gracilaria agar

2.5.2   Extraction of agarose from the seaweed

2.5.3   Extraction of agarose from the seaweed using powdered Eucheuma striatum instead of k-carrageenan

2.6   Determination of extract properties

2.6.1   Gel strength determination

2.6.2   Gelling temperature determination

2.6.3   4Melting temperature determination

2.6.4   Sulfate determination (AOAC Gravimetric method)

3.   AGAR AND AGAROSE APPLICATIONS

3.1   Applications in the food industry

3.2   Applications as culture media

3.3   Agar in impression materials

3.4   Agar in medicine and pharmacy

3.5   Other applications of agar

3.6   Application of agarose

4.   REFERENCES