Estimation of Ash Content from Several Minerals in Plant Foodstuffs

Abstract

  In order to develop simple and accurate methods for the estimation of the ash content in plant foodstuffs from the contents of several minerals, we analyzed 854 plant foodstuffs based on the standard tables of food composition in Japan. The following results were obtained :
1. The average ash content (±SD) was 2.1±3.8g and the ash contents of 616 foodstuffs, which accounted for 72% of all plant foodstuffs, ranged from 0 to 1.5g.
2. Both the sum of 9 minerals and that of 5 minerals significantly correlated with the ash contents.
3. Based on the multiple regression analysis, it was indicated that the ash content can be estimated from the sum of 5 minerals, i. e. , sodium, potassium, calcium, magnesium and phosphorous, in foods. The regression equation is as follows :
Predicted ash value (mg) =2.18×the sum of 5 minerals−110 .
4. There were considerable differences between the ash contents and the sum of the 5 minerals. Although the ash values from the standard tables of food composition did not show the sum of each mineral, they were reflected by their total contents.