Propriedades funcionais do ulvano e seus derivados

Abstract

Scientific research has been giving more and more importance to natural polymers, due to their versatility in terms of properties, variability, reduced environmental impact and reduced costs. Among these polymers, polysaccharides stand out due to their unique functional properties and enormous diversity found in nature. Seaweeds are a privileged source of polysaccharides which are composed of a vast range of molecules, such as rare sugars and sulphate groups, which due to their high bioavailability; give them an extremely broad range of properties. Among these properties, it is possible to highlight the anticoagulant, antihyperlipidemic, antioxidant, antiproliferative, antiviral, antihypertensive and immunomodulatory activities, and biomedical applications, as well as technological and environmental characteristics, among others. Green algae stand out among the different types of seaweeds, and in particular those belonging to the order Ulvales, in which the dominant polysaccharide that is found is called ulvan, and although its greater importance in scientific research is very recent, it already begins to demonstrate the wide range of estimated properties. The main goal of this study is an extensive review of the scientific literature in order to deepen existing knowledge on ulvan, to present evidence of their properties and to infer about new functionalities; both through a comparative analysis with similar polysaccharides on a physico-chemical level, as well as via modifications to the native form of the polymer, in particular via hydrolysis. In fact, many studied oligosaccharides have demonstrated an enhancement of their existing properties (associated with polysaccharides from which they derive) and possibly the appearance of new ones. A second objective of this study was to carry out a market survey in the municipality of Porto with the aim of verifying the existence and diversity of products based on seaweeds and, ultimately, of the ones containing ulvan and its derivatives. Detailed analysis of the literature allowed demonstrating that ulvan is a polysaccharide with very promising biological and technological properties, although its physico-chemical structure is not fully understood, and consequently the same applies to the mechanisms underlying its properties. It is also clear that, in order to increase the potential of the native polymer, some modifications could be applied, mainly hydrolysis, but further studies are required. Regarding the market survey, it was not possible to find ulvan containing products, but the diversity of products containing seaweeds that was found suggest the presence of an expanding market niche, in which ulvan can certainly have its place due to its unique properties.

Date of Award	2012
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Ana Maria Gomes (Supervisor) & Ana Carvalho (Co-Supervisor)