Comparison of the bioaccessibility of minerals in whole cow's milk and soy milk using an in vitro gastrointestinal digestion method and DRC-ICP-M

CECILIA DELLA VEDOVA; RAÚL GIL; MARÍA VIRGINIA PRÍNCIPE; MARCOS KAPLAN; SABRINA PERMIGIANI; CRISTIAN BAZÁN

Mendoza

Congreso; 15 Rio Symposium on Atomic Spectrometry; 2019

Universidad Nacional de Cuyo

Milk is a food used since ancient times as a source of protein and minerals by many cultures throughout the world(1,2). There is controversial information about this food and its true nutritional contributions, thus mineral bioaccessibility (BA) studies are necessary. The BA of the micronutrients Cu, Zn and Se were evaluated in soy and whole cow´s milk using an invitro digestion model which simulates the gastric and intestinal human digestion. Metal analysis was performed by inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS). The interferences from food matrix in ICP-MS were minimized by the use of methane as reaction gas in DRC. The dynamic bandpasstunning of DRC was optimized by modifying the rejection parameter (RPq) and methane flow rate monitoring the background equivalent concentration (BEC). The results of the total content of the micronutrients indicated that Zn was the mineral present in higher concentration, followed by copper and finally selenium. As a general trend, the BA of Zn was higher in the stomach than in intestine and the BA of Cu and Se increases progressively as it passes from stomach to the intestine in cow milk. In the case of soy milk, the highest mineral content was released in the stomach. In comparison, accessible fraction of minerals in soy milk were higher than in cow´s milk in all cases. However, other factors such as diet, fat content and origin of food may affect the bioaccessibility of mictonutrients.The total content of the minerals was validated by the analysis of a reference material (ERM-BD151, skimmed milk powder).