Incorporation of β-carotene O/W emulsions into dairy foods: Impact of the colloidal stability during in vitro digestion on the lipolysis and bioaccessibility

O/W emulsions have been proposed as delivery systems of lipophilic bioactive compounds into water-based foods. This work aimed to study the impact of the food matrix on the colloidal stability of R-carotene-loaded O/W emulsion incorporated into dairy products (milk and yogurt) before and during in vitro gastrointestinal (GI) digestion. The relationship between colloidal stability, lipolysis and R-carotene bioaccessibility was also evaluated. The colloidal stability of the O/W emulsion was maintained once it was incorporated into dairy products and during GI conditions, without a significant impact of the food matrix. However, lipolysis, as FFA release, was faster and higher once the O/W emulsion (64.58 +/- 2.76 %) was co-digested with dairy products (>81 %). Nevertheless, they presented non-significant differences in R-carotene bioaccessibility (38-44 %), thus dairy matrices would limit mixed micelles formation or R-carotene micellarization. This work provides valuable insight for designing dairy products fortified with bioactive compounds by using emulsions as delivery systems.