CHEMICAL-STRUCTURE AND PHYSICOCHEMICAL PROPERTIES OF AGAR

Advances in the chemistry and physico-chemical properties of agar since the review of Araki at the Fifth International Seaweed Symposium in 1965 are discussed. These advances are essentially the result of better separation techniques of the heterogeneous family of polysaccharides known as agar, the use of nuclear magnetic resonance spectroscopy, the use of agarases and, particularly, the use of combinations of the three approaches. Although physico-chemical methods have evolved, particularly molecular-weight determinations, X-ray diffraction data and molecular modelling of agar, correlations between chemical and functional properties of agar and agarose and their gelation mechanisms remain to be studied.