Biophysical Aspects of Lipid Digestion in Human Breast Milk and Similac™ Infant Formulas

Abstract

Physico-chemical properties of human breast milk were compared to four Similac ™ infant formulas, and correlated with in vitro free fatty acid bioaccessibility using a simulated gastrointestinal system (TIM-1). Viscoelastic measurements, as a function of pH (pH 6.5 to 3.0) and shear rate, showed lower viscosities in breast milk compared to infant formulas. Droplet size and distribution measurements showed distinct differences between the tested formulas and breast milk. During lipid digestion, a lag period was observed for only breast milk. The rate of lipolysis was found to be higher in breast milk compared to Similac ™ formulas. The total bioaccessible free fatty acids for Advance infant formula and breast milk were not statistically different for the in vitro TIM-1 model and the shifted-logistical model using one-way ANOVA (p<0.05) with a Tukey's Multiple Comparison Test. All other infant formulas had significantly lower free fatty acid bioaccessibilities at the end of the simulated digestion. A positive correlation between rate of lipolysis and droplet surface area per gram for the Similac ™ infant formulas was found. However, breast milk did not follow that trend, suggesting the possible involvement of other factors in rate of lipolysis for breast milk.

Investigating the Phospholipid Effect on the Bioaccessibility of Rosmarinic Acid-Phospholipid Complex through a Dynamic Gastrointestinal in Vitro Model

“…The physical and biochemical parameters used in the TIM-1 were determined on the basis of extensive in vivo data from both human and animal trials. This system has been widely used in the following aspects: To assess the bioaccessibility of natural extracts and nutritional products, to test the bioequivalence of a variety of drug formulations, to evaluate the gastrointestinal stability of phytochemicals, and to predict the drug–food interactions under different conditions including human fasting and fed states [37,38,39,40,41]. The validation of experimental parameters used for TIM-1 can be found in previous literature and the latest research [37,41,42,43].…”

Protein Digestion and Quality of Goat and Cow Milk Infant Formula and Human Milk Under Simulated Infant Conditions

“…An option is to use ex vivo gastrointestinal enzymes in static models ( 6 , 7 ). A better alternative might be the use of dynamic in vitro gastrointestinal models simulating infant digestion conditions ( 8 , 9 ). In the present study we used a dynamic in vitro gastrointestinal model (tiny-TIM) as described previously ( 10 , 11 ), improved with a 3-stage gastric compartment ( 12 ).…”

Bioavailability and bioaccessibility of food bioactive compounds; overview and assessment by in vitro methods

“…Recently, several researchers have used different in vitro dynamic digestion models to study the digestibility and BA of bioactive compounds from different matrices, such as digestibility of starch‐based infant foods (Passannanti et al., 2017), protein and starch digestion in short‐dough biscuits (Villemejane et al., 2016), lipid digestion in human breast milk and infant formulas (Fondaco et al., 2015), curcumin from emulsions prepared by layer‐by‐layer method (Silva et al., 2019), stearic and oleic acids from high‐oleic sunflower and canola stearin blend (Thilakarathna et al., 2016), and Fe 2+ from nanoparticles prepared by gelation of proteins in the presence of a scorbate (Martin & de Jong, 2012).…”