Carotenoid bioaccesibility from fruits by static in vitro digestion model: improvement proposals

Trabajo presentado a la 6th International Conference on Food Digestion (ICFD), celebrada en Granada (España) del 2 al 4 de abril de 2019.

[Introduction]: The bioaccesibility of carotenoids in foods is influenced by aspects related to the foods and by analytical factors (extraction and saponification methods, in vitro digestion protocols, etc).

[Objective]: To assess bioaccesibility of carotenoids in orange (Citrus sinensis, L.) using the protocols proposed by the COST Infogest network (Minekus et al., 2014, Alminger et al., 2014) slightly modified.

[Methodology]: Carotenoid analysis content and in vitro digestion were performed in fresh oranges. 5 or 20 g samples were weighed for in vitro digestion and the same for carotenoid analysis. In vitro digestion based on the standardized static in vitro digestion model proposed by COST. Phases: oral, gastric and small intestinal followed by separation of the supernatant. Two different protocols: Protocol 1: 5 homogenized sample (5g) was mixed with the reagents specified in the COST plus cholesterol esterase (Granado-Lorencio et al., 2007). Time for each phase: 2 min, 2 h and 2 h, respectively. After the digestion, centrifugation at 10000g for 10 min was carried up. Protocol 2: Similar to protocol 1 but 20 g of sample was used, gastric phase was shorted to 1 h. and centrifugation was performed at 20000g for 5 min.

[Main findings]: The weight of the homogenized sample was increased for an improved identification/quantification of carotenoids. In previous centrifugation assays in kiwis (Actinidia deliciosa), bioaccesibility was: 8.9% (5000g, 20 min), 10%, 6.4%, 5.1% (10000g, 5,10 and 20 min, respectively) and 16.6% (20000g, 5 min). Bioaccesibility of B-cryptoxanthin in orange: 1.1 % and 47.1 % (protocols 1 and 2, respectively).

[Conclusion]: A precise protocol to estimate bioaccesibility of carotenoids in fruits and vegetables should include precise information on the centrifugation step (to get fraction containing the micellized carotenoids) and the period of time for the gastric phase.

Instituto de Salud Carlos III (grants PS09/00681, PI16/01991)(Co-funded by ERDF/ESF)

Peer reviewed