Bioaccessibility of provitamin A carotenoids from fruits: application of a standardised static in vitro digestion method

Provitamin A carotenoids (beta-carotene, alpha-carotene, and beta-cryptoxanthin) contribute to the dietary intake of vitamin A and are associated with decreased risk of many chronic diseases. Besides their contents in foods, their bioaccessibility is of great interest since it represents the amount that will be absorbed in the gut. The aim of this study was to adopt, for the first time, the in vitro digestion model suitable for food, proposed in a consensus paper by Minekus et al. (2014), to assess the bioaccessibility of carotenoids from the fruits that are the major contributors to the intake of beta-cryptoxanthin in Spain (orange, tangerine, red pepper, peach, watermelon, and persimmon) and loquat. The highest beta-cryptoxanthin content and the lowest bioaccessibility was found in mandarin and loquat (13331.6 and 929.2 mu g per 100 g respectively), whereas the highest contents of beta-carotene and alpha-carotene were recorded in red pepper (1135.3 and 90.4 mu g per 100 g respectively). The bioaccessibility of beta-cryptoxanthin was similar to that of beta-carotene (0.02-9.8% and 1-9.1%, respectively) and was higher than that of beta-carotene in red pepper, watermelon and peach. alpha-Carotene bioaccessibility ranged between 0% and 4.6%. We discuss the critical factors for comparing our data: the form of the food being analyzed (raw/cooked/previously frozen, in the presence or absence of oil/fat) and the protocol for bioaccessibility assessment. Different food processing techniques may increase carotenoid bioaccessibility compared to raw food. However, given the difficulties encountered when comparing the results of studies on bioaccessibility, it seems logical to propose the application of the previously mentioned standardized in vitro protocol.