Table 1.

Properties of naturally derived biogenic polymers used in food packaging.

Biogenic Polymer	Monomeric Unit	Structure of Monomeric Unit	Properties
Cellulose/Nanocellulose	D-glucose		Most abundant biopolymer on earth. Monomers are joined by β-1,4 glycoside bonds. The elementary organization of cellulose is fabricated from micro sized string-like structures microfibers, which are further made up of nanosized microfibrils [60]. Non-toxic nature and exceptional strength to weight ratio marks it a preferred choice for food packaging materials [61].
Chitin	N- acetylglucosamine		Derived from the exoskeletons of crustaceans. Composition is identical to cellulose, except for an acetamide group on the alpha carbon atom instead of the secondary hydroxyl group in the cellulose molecule. Utilized for the generation of chitosan by a process of deacetylation using an alkali [27].
Chitosan	N-acetyl-D-glucosamine		Semicrystalline and easily soluble in organic acids such as malic, lactic, etc. [62]. Biodegradable, nontoxic, biocompatible [28]. Positively-charged, a linear polysaccharide made from β-(1-4)-linked D-glucosamine and N-acetyl-D-glucosamine units [63]. The degree of acetylation may vary from 0 to 70% [29]. Higher affinity for water [32]. Antagonistic activity against bacteria and fungi [64].
Carrageenan	Sulfated d-galactose and l-anhydrogalactose		Obtained from the red edible seaweed family also known as Irish Moss [65]. Linear chains of alternating 3-O-substituted β-d-galactopyranosyl units and 4-O-substituted α-d-galactopyranosyl units. It exists in three forms: (i) kappa: ability to produce hard and stiff gels in the companionship of potassium ions, (ii) iota: creates soft gels with calcium ions, (iii) lambda: does not possess gelling properties and is used as a thickening agent. Less resistance to water and exhibits excellent mechanical properties [66] Possesses amazing gelling ability, good film-forming properties, having optimal transparency and TS [67].
Starch	Glucose monomers joined in α 1,4 linkages		Native starch polymers are tasteless and odorless, semipermeable to gas, water, and flavoring components [30]. Packaging obtained by using starch as a base material is flexible, transparent, environmentally friendly, and cheap [68]