Cell wall polysaccharides implied in green olive behaviour during the pitting process

Abstract

Olive fruits processed as “Spanish green olives” were sorted into two batches depending on their pitting behaviour: those that broke under punch pressure, and those that were pitted without damage. Cell wall polysaccharides from both batches were isolated. The main changes were lower amounts of carbonate-soluble and 24 % KOH-soluble polysaccharides and a higher proportion of 4% KOH-soluble polysaccharides in broken olives. The carbonate-soluble fraction from broken olives was poorer in homogalacturonans, polysaccharides that could help in increasing texture. The 24% KOH-soluble fraction from the same olive batch was poorer in xylans and xyloglucans, the former being present in a higher proportion in the 4% KOH-soluble fraction and the last in cellulose residue. The new xylans of the 4% KOH-soluble fraction were of high (around 250 kDa) and low (6–40 kDa) molecular weights. Carbonate-soluble and 24% KOH-soluble fractions are very important in maintaining cell wall structure, which is responsible for vegetable product firmness.