Mild thermal treatment and in-vitro digestion of three forms of bovine lactoferrin: Effects on functional properties

In-vitro digestion behaviour of iron saturated (holo)-, native- and iron depleted (apo)- bovine lactoferrin (LF) was studied in simulated oral, gastric and intestinal digestion conditions. All LFs were hydrolysed to <10 kDa peptides; 93% of iron was released from holo-LF within 2 h of gastric digestion. Iron binding ability of all the three LFs was decreased by 80-90% during gastric digestion, while antioxidant activities at the end of gastric digestion were 3-8 times higher than those at the end of oral and intestinal digestion. Antioxidant activity of apo-LF was higher than that of holo-LF after gastric and intestinal digestion. Gastric and intestinal digestion of all the three forms of LF produced negatively charged peptides or amino acids. There were only minor differences among the three forms of LF in terms surface charge, hydrolysis patterns and iron binding/release characteristics between heated and unheated LF samples after gastric digestion.