To investigate water-boiling on the nutritional value of trace elements, establish a bioaccessibility-based evaluation system for Zea mays L. mineral quality, and assess the changes in the bioaccessibility and comprehensive nutritional contribution of major minerals in Zea mays L. induced by water-boiling.

The 2 kinds of representative commercially available Zea mays L. samples (M1 and M2)were selected and treated by water-boiling. Using the physiologically based extraction test (PBET), an in vitro digestion model that simulates the human gastrointestinal environment, this study determined and compared the changes in the total concentrations of 8 kinds of mineral elements in Zea mays L. before and after water-boiling treatment, including potassium (K), phosphorus (P), magnesium (Mg), calcium (Ca), iron (Fe), manganese (Mn),copper (Cu)and zinc (Zn), together with their bioaccessibility in the small intestinal phase. Furthermore, to more accurately reflect actual human absorption, a multidimensional nutritional quality evaluation model was established for quantitative analysis based on estimated daily intake (EDI), contribution to recommended nutrient intake (RNI),and index of nutritional quality (INQ).

Water-boiling treatment altered the matrix structure and affected the bioaccessibility of minerals in Zea mays L., with different elements presenting differentiated trends. The bioaccessibility of Zn, Mn, and Mg increased by 7%–45%. The bioaccessibility of Ca and Cu decreased by 14%–49%. K exhibited extremely high solubility stability, whereas Fe and P achieved a recovery of release in the small intestine stage. Data assessment based on bioaccessibility showed that Zea mays L. was a stable and high-quality dietary source of K, P and Mg. Estimated based on conventional consumption amounts, the EDI of its edible parts and the contribution rate to the RNI were both at relatively high levels; INQ analysis further confirmed that even afterwater-boiling, Zea mays L. still possessed good nutritional value in providing K, P, and Mg, belonging to high-nutrient-density quality foods.

This study reveals that water-boiling exerts a bidirectional regulatory effect on the bioaccessibility of mineral elements in Zea mays L., thereby altering their final nutritional quality. This study indicates that the total concentration of minerals in food cannot accurately reflect the degree of their actual absorption and utilization by the human body. When performing food dietary nutritional evaluation and processing technology optimization, it is necessary to consider bioaccessibility indicators in combination with traditional total concentration indicators to more scientifically and accurately assess the actual nutritional contribution of processed foods. This finding provides a key theoretical basis for nutritional loss assessment in household cooking,precise dietary guidance for special populations and the optimization of food processing technologies.