“It has been claimed that polysaccharides are relatively simple substances without much variety in terms of their structure and their application in an industrial or medical contact.” Write an essay giving a reasoned treatise why you do or do not agree with this statement. In your answer, compare and contrast the structure, costs of production, possibility for chemical/enzymatic modification and the industrial applications of two structural polysaccharides (such as pectins and celluloses), 2 marine polysaccharides (alginate and chitosan) and 2 bacterial polysaccharides (xanthan and gellan gum).
One would not have thought that even though the basis of polysaccharides are from highly similar building block of furanose carbohydrate ring structure or pyranose, its potential biotechnological application are vast given its variety of functional and structural properties. Unlike protein, polysaccharide are usually homopolymers made from hexose or pentose residues. One example of homopolysaccharides or single type of sugar is cellulose while heteropolysaccharides with two or more sugars is guar gum which consist of mannose and galactose. Structure of homopolysaccharide (Foster 2013)
Some of the reasons responsible for variety in polysaccharide structure is its hydrodynamic properties where branced chain are common and also the manner of hexose and pentose linkage which contributes to different chain formation. Structural polysaccharide are polysaccharide that are involves in forming the structure of organisms such as cellulose in plants and chitin in insects and crabs.
Pectin is a structural polysaccharide mainly found in the primary cell walls of terrestrial plants where they contribute to physiological processes such as cell differentiation and cell growth. Pectin extraction can be done by enzymatic extraction where there are four main enzymes that can act on it. The first one is pectin lyase that make bonds cleave
References: Ali, A., Muhammad, M., Sijam, K. and Siddiqui, Y. (2011). Effect of chitosan coatings on the physicochemical characteristics of Eksotika II papaya (Carica papaya L) fruit during cold storage. Food chemistry, 124(2), pp.620--626. Economic Analysis of Postharvest Technologies for Vegetables - Google Livres. 2014. Economic Analysis of Postharvest Technologies for Vegetables [ONLINE] Available at:http://books.google.fr/books?id=L5M2AgAAQBAJ&pg=PA84&lpg=PA84&dq=postharvest+cost+chitosan&source=bl&ots=RFZoi8lUzv&sig=apa3Ltqp9hZTv-neiQius0g7SK4&hl=fr&sa=X&ei=RTxaU77COuiV0QX00oGIDw&ved=0CDMQ6AEwAA#v=onepage&q=postharvest%20cost%20chitosan&f=false. [Accessed 11 April 2014]. Foster, T 2013, Fundamentals of polysaccharide structure, lecture notes distributed in Industrial and Biomedical Macromolecules at The University of Nottingham. Tombs, M. and Harding, S. (1998). An introduction to polysaccharide biotechnology. 1st ed. London: Taylor & Francis. Understanding food additives, (2014). An introduction to pectin. [online] Available at: http://www.understandingfoodadditives.org/activities/G2.com [Accessed 11 Apr. 2014].