remove oil/fat and chyme residues from the pH bulb after pH
measurement.
12. The use of glass bottles is mandatory because intestinal
enzymes bind to the plastic materials, so that efficiency of the
enzymatic activity is reduced.
13. Determine the amount of 1 M HCl or 1 M NaOH required
adjusting the pH value at the gastric and intestinal phase,
respectively, in a test experiment so that their addition can be
subsequently made quickly. Monitor the pH values at the
beginning and intermediate periods of both digestion phases
in one of the replicates and adjust the pH value if necessary.
14. Be careful not to disturb the pellet or the solvent phase.
15. We use the free software ImageJ that performs density or grey
scale measurement/calibration [18]. Optical density step
tablets to calibrate an image are commercially available from
Tiffen (Kodak) and Stouffer. The densitometry on bands
corresponding to the triacylglycerides, mono- and diacylglycerides, and free fatty acids at the beginning of the digestion
phase is the reference value for obtaining the lipolysis efficiency.
Acknowledgments
The financial support of the Ministerio de Economı ´a y Competitividad (MINECO-CICYT, Spanish Government, project
AGL2017-87884-R) is gratefully acknowledged. Antonio Pe ´rezGa ´lvez is a tenured scientist at the Spanish National Research
Council (CSIC).
Fig. 2 Different particle size distributions of bile extracts purchased from the same dealer
Carotenoid In Vitro Digestion
385
measurement.
12. The use of glass bottles is mandatory because intestinal
enzymes bind to the plastic materials, so that efficiency of the
enzymatic activity is reduced.
13. Determine the amount of 1 M HCl or 1 M NaOH required
adjusting the pH value at the gastric and intestinal phase,
respectively, in a test experiment so that their addition can be
subsequently made quickly. Monitor the pH values at the
beginning and intermediate periods of both digestion phases
in one of the replicates and adjust the pH value if necessary.
14. Be careful not to disturb the pellet or the solvent phase.
15. We use the free software ImageJ that performs density or grey
scale measurement/calibration [18]. Optical density step
tablets to calibrate an image are commercially available from
Tiffen (Kodak) and Stouffer. The densitometry on bands
corresponding to the triacylglycerides, mono- and diacylglycerides, and free fatty acids at the beginning of the digestion
phase is the reference value for obtaining the lipolysis efficiency.
Acknowledgments
The financial support of the Ministerio de Economı ´a y Competitividad (MINECO-CICYT, Spanish Government, project
AGL2017-87884-R) is gratefully acknowledged. Antonio Pe ´rezGa ´lvez is a tenured scientist at the Spanish National Research
Council (CSIC).
Fig. 2 Different particle size distributions of bile extracts purchased from the same dealer
Carotenoid In Vitro Digestion
385