Step 1: Concept Overview:
Pectin, a complex polysaccharide in plant cell walls (especially fruits), is a common food industry ingredient. It functions as a gelling agent, thickener, and stabilizer, notably in jams and jellies.
Step 3: Detailed Explanation:
Pectin's main structure is a linear chain of D-galacturonic acid units linked by \(\alpha\)-(1\(\rightarrow\)4) glycosidic bonds.
Galacturonic acid is a sugar acid derived from galactose.
The term galacto-pyranosyl uronic acid is the formal chemical name for galacturonic acid when in its pyranose (six-membered ring) form within a polymer.
The other options are incorrect because:
- (A) Galactose and glucose are monosaccharides (simple sugars).
- (B) Fructose is a monosaccharide.
- (D) Amylose, a polysaccharide found in starch, is composed of glucose units.
Step 4: Conclusion:
Galacturonic acid, also known as galacto-pyranosyl uronic acid in its ring form, is the fundamental building block of pectin. Therefore, option (C) is correct.