Because of their potential use as functional ingredients in human nutrition, oligosaccharides derived from natural sources are receiving paramount consideration. Red seaweed, a proven rich source of agar and carrageenan, is one of the most abundantly present sources of such oligosaccharides. Agaro-oligosaccharides (AOS) and carrageenan-oligosaccharides (COS) are produced from agar and carrageenan, respectively, through chemical and enzymatic hydrolyses. Enzymatic hydrolysis of agar and carrageenan into oligosaccharides is preferred in industrial production because of certain problems associated with chemical hydrolysis, including the release of high amounts of monosaccharides and undesirable toxic products, such as furfural. AOS and COS possess many biological activities, including prebiotic, immuno-modulatory, anti-oxidant, and anti-tumor activities. These activities are related to their chemical structure, molecular weight, degree of polymerization, and the flexibility of the glycosidic linkages. Therefore, the structure–function relationship and the mechanisms occurring during the specific biological applications of AOS and COS are discussed herein. Moreover, the chromatographic separation, purification, and characterization of AOS and COS are also part of this review. This piece of writing strives to create a new perspective on the potential applications of AOS and COS in the functional food and pharmaceutical industry.

The extremely vast biodiversity represented by marine mollusks alongside their widespread utility as a source of food and their high nutritional value has aroused great interest from the scientific community. Furthermore, they can be caught with ease, and their commercial breeding and farming is rampant. This article comprehends the global availability of these organisms, their pretreatment and handling procedures, and their health‐promoting potential with a focus on their antiviral, anti‐inflammatory, and antimicrobial properties. The emphasis herein is on their potential use in the food and nutraceutical industry. In addition, mollusks consumption as part of everyday diet can also be helpful in avoiding many ailments as they are rich in vital nutrients and active secondary metabolites, as well as have the ability to enhance immune response. Moreover, the available literature suggests that normal cooking practices have no notable adverse effects on their nutritional value and they retain certain bioactivities even after the action of digestive enzymes. Though mollusks have been widely studied in relation to the health‐promoting effects reviewed here, there is still more scope for further research in this direction in order to fully utilize this enormous source of food and nutraceuticals.