Formulating healthy food rich in omega 3 fatty acids requires prior knowledge of the parameters influencing their bioavailability and their metabolic fate. In this context, we studied the effects of various emulsifiers widely used in the food industry, on the gastrointestinal lipolysis of flaxseed oil emulsions in an in vitro model and on the intestinal absorption and lymphatic secretion of alpha-linolenic acid (ALA) in rats. In vitro data showed that the emulsification of flaxseed oil with soya lecithin improved the gastric lipolysis of the oil (+30%), while the presence of Tween 80 or of sodium caseinate decreased it (-80% and -40%, respectively). The in vivo data demonstrated that the intestinal absorption and the lymphatic secretion of ALA were improved with soya lecithin (Cmax = 24 mg mL(-1)) and reduced in the presence of sodium caseinate (Cmax = 7 mg mL(-1)) compared to unemulsified flaxseed oil (Cmax = 16 mg mL(-1)); Tween 80 had no effect. In addition, the synthesized chylomicrons were notably larger and more numerous with soya lecithin whereas they were smaller in the presence of sodium caseinate (p < 0.05). This study shows that the intestinal bioavailability of ALA was increased by the emulsification of flaxseed oil with soya lecithin via an improved lipolysis, favouring the intestinal absorption of ALA and the secretion of many large chylomicrons in lymph.
There is a growing interest in the optimization of dietary emulsions for monitoring postprandial lipid metabolism in the frame of preventing metabolic diseases. Using various emulsions, we investigated in a systematic scheme the combination of (i) in vitro gastrointestinal lipolysis and (ii) absorption and metabolism of lipolysis media in Caco-2 cells. Four emulsions based on either milk fat olein (OL) or rapeseed oil (RA) as the dispersed phase and either lecithin (LE) or sodium caseinate (CA) as the emulsifier were tested. After a sequential incubation of these emulsions with gastric and pancreatic enzymes, lipolysis media were incubated with Caco-2 cells, after dilution (1 : 20) to maintain the barrier integrity. Both gastric and duodenal lipolysis levels were similar to values reported in vivo and the rates of lipolysis were higher with LE-stabilized emulsions than with CA-stabilized emulsions (P < 0.05). TAG secretion by Caco-2 cells was found to be higher using (i) duodenal vs. gastric media (P < 0.001) and (ii) emulsions stabilized with CA vs. LE (P < 0.01). Consistently, gene expression of both FABP2 and FATP4 induced by the duodenal media was (i) higher than that with gastric media (P < 0.001) and (ii) faster than that with model mixed micelles. Using gastric media, TAG secretion of Caco-2 cells after 12 h was higher with RA than with OL (P < 0.001). Moreover, the RA-CA emulsion increased the size of secreted lipoprotein particles (514 nm vs. 61 to 130 nm; P < 0.01). In conclusion, it was possible to observe distinct responses in the lipid metabolism of Caco-2 cells incubated with lipolysis media obtained from different dietary emulsions digested by gastrointestinal lipases in vitro.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.