Rapid indirect method for determining the sodium content of table olives

Abstract

Methods for the determination of sodium in olives were studied. Direct measurement by photometric and ion-selective electrode methods did not show systematic errors, with the latter being more precise and easier to apply. The correlation (p⩽ 0.001) between NaCl concentration in the surrounding brine (calculated using the official Volhard procedure) and Na⁺ content in the olive flesh (determined using an ion-selective electrode, the most practical of the two methods tested) was of particular interest and permitted the determination of the latter from determinations of the former. This indirect measurement enables producers to determine the sodium content in packed olives non-destructively using an established method. It also avoids the problems of obtaining representative samples and the tedium of samples preparation.