Comprehensive stability evaluation of iron-fortified milk powder

Abstract

Well-documented stability studies on iron-fortified food are limited due to the complexity of ingredients and processing methods. Here, we performed a comprehensive stability evaluation on iron-fortified milk powder with various iron contents and packaging methods. Free fatty acid increased gradually over a 9 month storage period in both iron-fortified and non iron-fortified formulas, regardless of the packaging methods. Thiobarbituric acid (TBA) value level remained stable in anaerobic packaging condition but increased in aerobic condition. Lipid oxidation was highest in Fe(III)-fortified formula. We showed significant increment of browning reactions, moisture and water activities in aerobic condition, especially in iron-fortified formulas, while no significant changes in anaerobic-packaged formulas. Scanning electron microscopy (SEM) showed highest porosity in Fe(III)-fortified formula. Our results showed Fe(III)- fortified formula has the lowest stability in aerobic condition but its stability improved significantly with vacuum/anaerobic packaging. Thus, our studies contribute to understanding and improving the processing and quality of iron-fortified food.