Effect of industrial processing on the mineral content of white asparagus

Abstract

Concentrations of calcium, magnesium, sodium, potassium and phosphorus were determined in white asparagus (Asparagus officinalis, L.) by atomic absorption spectrophotometry to investigate and estimate if the influence of industrial processing on mineral content and mineral nutritional value of different varieties, diameters and portions of white asparagus spears. Four‐factor anova (processing, variety, diameter and portion) and a Scheffè test (P < 0.05) established statistically significant differences and different homogeneous groups for the four factors. All the elements studied showed significant (P < 0.001) changes in their levels throughout the processing stages with a decrease of the calcium and sodium content and an increase in magnesium, potassium and phosphorus concentrations. These variations are especially related to peeling since the loss of the spear peel may produce changes in the mineral content. Concentrations of the majority of the mineral elements analysed were higher in the SUR variety asparagus, the largest diameter spear (14–19 and > 19 mm) and the tip and middle portions of the spear. Nutrient density was well over 100% for all the elements, except for sodium, and the processing has no consequences for the mineral nutritional value.