Characterization of Zinc Components on in vitro Enzymatic Digestion of Foods

Beef and polished rice were subjected to in vitro digestion and the soluble zinc components separated by gel filtration. Approximately 30% of beef zinc was solubilized by digestion; and more than 30% of rice zinc was solubilized. Most of the soluble zinc was found in one or two proteinaceous components with molecular weight of 1,270‐5,130 dalton. Amino acid analyses showed that these proteinaceous components were high in the acidic amino acids and glycine, and low in L‐histidine. These findings suggest that these proteinaceous components, as they combine with zinc, may increase the amount of soluble zinc.