Background: Non-digestible oligosaccharides are versatile sources of chemical diversity, well known
for their prebiotic actions, found naturally in plants or produced by chemical or enzymatic synthesis or by hydrolysis
of polysaccharides. Compared to polyphenols or even polysaccharides, the antioxidant potential of oligosaccharides
is still unexplored. The aim of the present work was to provide an up-to-date, broad and critical contribution
on the topic of antioxidant oligosaccharides.
Methods: The search was performed by crossing the words oligosaccharides and antioxidant. Whenever possible,
attempts at establishing correlations between chemical structure and antioxidant activity were undertaken.
Results: The most representative in vitro and in vivo studies were compiled in two tables. Chitooligosaccharides
and xylooligosaccharides and their derivatives were the most studied up to now. The antioxidant activities of
oligosaccharides depend on the degree of polymerization and the method used for depolymerization. Other factors
influencing the antioxidant strength are solubility, monosaccharide composition, the type of glycosidic linkages
of the side chains, molecular weight, reducing sugar content, the presence of phenolic groups such as ferulic
acid, and the presence of uronic acid, among others. Modification of the antioxidant capacity of oligosaccharides
has been achieved by adding diverse organic groups to their structures, thus increasing also the spectrum of potentially
Conclusion: A great amount of high-quality evidence has been accumulating during the last decade in support of
a meaningful antioxidant activity of oligosaccharides and derivatives. Ingestion of antioxidant oligosaccharides
can be visualized as beneficial to human and animal health.