Pectin extraction from citrus peels and apple pomace is commercially carried out under which physicochemical conditions?
Options:
(A) Hot dilute acid extraction ($pH\;1.5 - 2.5$ at $70 - 90^\circ\text{C}$) followed by alcohol precipitation
(B) Cold alkaline saponification ($pH\;12$ at $10^\circ\text{C}$)
(C) Supercritical carbon dioxide extraction at $300\text{ bar}$
(D) Hexane solvent extraction
Answer Key:
A
Step-by-Step Solution & Explanation
Protopectin in citrus/apple cell walls is insoluble. Mild hot acid hydrolysis ($pH\;1.5 - 2.5$ using hydrochloric or nitric acid at $70 - 90^\circ\text{C}$) hydrolyzes protopectin into soluble pectin, which is subsequently precipitated by adding ethanol or isopropanol.