Calcium and pectin influence on peach flesh texture

Thirty-four peach cultivars and seedlings were tested for firmness, skin background colour, TSS, ethylene production. In addition, total? soluble and insoluble pectins and both total and pectin-bound calcium were measured. Melting, non-melting, stony hard phenotypes were included and a possible novel "crispy" phenotype as well. Firmness was not related to flesh texture. While total pectin content did not determine firmness, both soluble and insoluble pectin were related to firmness. Stony hard phenotypes showed a very high content of calcium and total pectin. The "crispy" types had a very high level of calcium bound to insoluble pectins. This finding could possibly explain their textural features due to the allocation of calcium ions in cell walls. The relationship between pectins total and pectin-bound calcium seems to add an interesting field of research for defining objective methods for assessing flesh texture in peach.