*3.2.2 Alginates*

Alginates belongs to sulfate polysaccharide, exist in brown algae species with the linear structure of copolymers, and the basic units of β-D-mannuronate (M) and α-L-guluronate (G) that links via (1,4)-glucoside linkage. Alginate content is about 15 to 25% of dry algae [26]. Nowadays, over 200 different alginates appear in the market [27]. Different alginates have various G/M ratio and molecular weight that depend on the season, species, and growth sites. G/M ratio and molecular weight play an important role in exhibiting bioactive and application of alginate. Alginates form a

**Figure 2.** *(a) Alginate in 96% ethanol; (b) pectin from cactus Opuntia dillenii.*

robust and rigid gel when low the M/G proportion and large guluronic blocks ratio in their structure, and reverse forming soft and elastic gels [28, 29]. Alginates possess a molecular mass larger than 50 kDa exhibiting the prevention ability of diabetes and adiposity. Numerous studies showed that antioxidant activity is also one of the bioactive characteristics of alginates [30, 31]. Therefore, alginates are useful in the food, cosmetic, functional food, pharmaceutical, even dentistry, and toothpaste such as stabilizers, emulsifying agents, or thickeners. Puried alginate has white color (**Figure 2a**).

#### *3.2.3 Glucosamine*

Glucosamine sulfate (2-amino-2-deoxy-D-glucose) is the sulfate derivatives of chitosan that formed after deacetylation for chitin. Glucosamine sulfate is an essential amino monosaccharide in connective tissues (cartilage and ligaments) of marine invertebrates and commonly the material for synthesizing glucosaminoglycans, glucoprotein, and glucolipide [32]. Nowadays, crab, lobster, or shrimp shells are materials for producing glucosamine. Numerous studies showed that glucosamine could exist in glucosamine hydrochloride, glucosamine sulfate, and N-acetylglucosamine and links to chondroitin sulfate in the connective tissues. The biological activity of glucosamine is proven (antioxidant, antiinflammatory, induce ER stress, antigenotoxic, cardioprotective, neuroprotective, O-GlcNAc modification, and antifibrotic) and is in positive proportion to the sulfate groups in their structure [33, 34].

#### *3.2.4 Inulins*

Inulins belong to the fructooligosaccharides group, composed of linear fructosyl polymers and oligomers with degree polymerization (DP) (3–65). DP of inulins in chicory consists is from two to approximately sixty units. In inulin, terminal glucose residues unit the non-reducing end via an α-(1,2) glycosidic bond and contains two or more fructosyl moieties that link each other by β-(2,1) bonds. The fructooligosaccharides (fructose oligomers) possess one glucose unit and two to four fructose units. Short fructooligosaccharides compose of 1-kestose, nystose, and 1F-fructofuranosylnystose. Small inulin oligomers (degree polymerization <10) are oligofructose and fructooligosaccharides. Inulins in plants and fungi contain β-(2,1)-D fructofuranosyl units [35]. Antioxidant activity of inulin is higher than simple sugars (fructose, glucose, and sucrose) and stable under the impact of the cooking and digestion processes (pH changes, digestive enzymes). Inulin unaltered better than ascorbic acid that lost from 40 to 90% of antioxidant activity at high temperatures. The antioxidant role of inulins exhibit better than other ROS (radical oxygen system) scavengers (vitamins C and E – the absorbance in the first part of the gut) because inulin is absorbent in the colon that occurs in vitamins C and E.

#### *Functional-Antioxidant Food DOI: http://dx.doi.org/10.5772/intechopen.96619*

Inulins against protein oxidation are basing on the protection of the mucosal and the submucosal layers. Fructans (inulin style) respond to a defensive role against oxidative stress, at the same time activating automatic before the endogenous systems of detoxification in rats. Radical oxygen system scavenging capability of oligosaccharides in intra-peritoneal administration in vivo decide the decrease of lipid peroxidation. Besides inulins, levans (high molecular weight polymer) are about 107 Da with type β-2,6 linkages. Galactopyranosyl oligomers possess DP (3–8) with mostly β-(1,4) or β-(1,6) bonds and less β (1,2) or β-(1,3) linkages. Levans can combine various metal nanoparticles such as Levan–Fe2+ and levan–Cu+ that ROS inhibition up to 88% and 95%, and the combination exhibit antioxidant activity better than 33–40%, compared to single levans [35]. Moreover, levans possess numerous bioactivities, for example, antioxidants, anti-tumor, and anti-inflammatory [36].
