Changes in Crystallinity of Cellulose During Dehydration

Abstract

SUMMARY—Samples of onions and bell peppers were taken during various stages of high‐ and low‐temperature dehydration and lyophilization to ascertain the step‐wise changes that occur in the crystallinity of cellulose. Cellulose crystallizes mainly during the later stages of drying in all three processes, and freezing produces only a minor amount of crystallization. Most of the water loss and loss of rehydration capacity occurs at the start of dehydration. The latter is ascribed to cell death and loss of differential permeability in protoplasmic membranes. Rehydration volume is related to crystallinity of cellulose in these materials within each method of dehydration.