| Résumé | Carrageenan is the generic name given to a family of sulfated polysaccharides extracted from some red seaweeds (Rhodophyta). They are made of repeating d‐galactose units linked alternately via α‐1, 3 and β‐1, 4 linkages. Units can have various sulfation patterns and often the α‐d‐galactose moiety is replaced by a 3,6‐anhydro‐α‐d‐galactose moiety. Carrageenans have long been used in the food industry (E407), in drug formulations, and in cosmetic products for their texturizing and gelling properties. Novel applications of carrageenans are moving toward the use of designed poly‐ and oligosaccharides that have specific functionality. In this respect, the use of specific carrageenan‐modifying enzymes is essential. There are two distinctive sets of enzymes: those that desulfate (sulfatases and sulfurylases) and the carrageenan hydrolases, also called carrageenases. These enzymes are used to produce specific oligosaccharides that are gaining in importance as they display biological activities in human health and plant growth and protection. The sulfurylases and sulfatases are able to specifically biochemically convert carrageenans into another carrageenan form. In this chapter, we review all the enzymes that are now available to bioconvert carrageenans, and we also present some of their possible uses. Perspectives of blue technology rely on potent analytical methods for in‐depth studies on the enzymatic modifications. Thus, the three main spectroscopic methods (infrared, nuclear magnetic resonance, and mass spectrometry) used for this purpose are presented. |
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