Estimation of carotenoid accessibility from carrots determined by an in vitro digestion method.
OBJECTIVE
To develop an in vitro digestion method to assess the impact of heat treatment, particle size and presence of oil on the accessibility (available for absorption) of alpha- and beta-carotene in carrots.


METHODS
Raw and cooked carrots were either homogenized or cut into pieces similar to chewed items in size. The carrot samples, with or without added cooking oil, were exposed to an in vitro digestion procedure. Adding a pepsin-HCl solution at pH 2.0 simulated the gastric phase. In the subsequent intestinal phase, pH was adjusted to 7.5 and a pancreatin-bile extract mixture was added. Carotenoids released from the carrot matrix during the digestion were extracted and quantified on high-performance liquid chromatography (HPLC).


RESULTS
Three percent of the total beta-carotene content was released from raw carrots in pieces. When homogenized (pulped) 21% was released. Cooking the pulp increased the accessibility to 27%. Addition of cooking oil to the cooked pulp further increased the released amount to 39%. The trends for alpha-carotene were similar to those for beta-carotene.


CONCLUSIONS
The described in vitro digestion method allows a rapid estimation of carotene accessibility in processed carrots, which may reliably predict in vivo behavior.


BACKGROUND
This study was supported by the Swedish International Development Cooperation Agency (SIDA) and the International Program in the Chemical Sciences (IPICS), Uppsala University, Sweden.
Hedrén
E
E
Department of Food Science, Chalmers University of Technology, Göteborg, Sweden. eleen.hedren@fsc.chalmers.se
Diaz
V
V
Svanberg
U
U
D000975:Antioxidants / Q000493:pharmacokinetics*; D001682:Biological Availability; D002338:Carotenoids / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D003296:Cooking; D018552:Daucus carota / Q000737:chemistry*; D004041:Dietary Fats / Q000494:pharmacology; D004063:Digestion; D005511:Food Handling / Q000379:methods; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D009753:Nutritive Value; D010316:Particle Size; D019207:beta Carotene / Q000378:metabolism / Q000493:pharmacokinetics
D000975:Antioxidants; D004041:Dietary Fats; D019207:beta Carotene; D002338:Carotenoids