Effect of Calcium Ion on the Texture of Canned White-pulp Peaches

Abstract

Calcium ions(0-300ppm)were added to canned white-pulp peaches(Nunome-wase, Mishima-hakuto and Okubo) in order to keep good quality and to prevent softening or breakdown of pulp texture during transportation.
It was observed that the drained weight, firmness of pulp, and calcium content in alcohol insoluble solids(AIS)from peach pulp increased in almost direct proportion to the concentration of the added calcium ions. Water-soluble pectin in AIS showed a tendency to decrease, whereas both oxalate-soluble and hydrochloric acid-soluble pectins increased with increasing calcium content. Shaking with an automatic shaker for 18hrs, the calcium-added peach pulp showed no breakdown, but in peaches without calcium, breakdown was observed among about one-third of the tested pulp.