In Vitro Bioaccessibility Protocol for Chlorophylls

Abstract

The daily ingestion of chlorophylls has been estimated at 50 g, but the knowledge about their bioaccessibility is limited. Different in vitro models have been utilized to estimate their potential bioavailability, but among other factors, the diversity of structures, chemical properties, and lability of chlorophylls hamper the investigations. By the first time, three extreme food matrices, one rich in fiber (vegetable puree), one rich in fat (virgin olive oil), and one liquid (fruit juice), have been assayed for chlorophyll bioaccessibility, controlling crucial variables. Chlorophyll polarity and food matrix were the determining factors, but surprisingly, chlorophyll bioaccessibility was affected during the application of the in vitro standardized protocol. Therefore, the present research has identified the reactions that can be biased during the estimation of chlorophyll bioaccessibility, defining a specific protocol in the function of chlorophyll structures.

Keywords: bioaccessibility; chlorin; chlorophylls; fruit juice; in vitro digestion; micellarization; pheophorbide; pheophytin; pyropheophytin; vegetable puree; virgin olive oil.

Figure 1

Chlorophyll structures present in the mixed micelles formed during the in vitro digestion of a vegetal puree, fruit juice, and virgin olive oil.