Lymphatic absorption of α-linolenic acid in rats fed flaxseed oil-based emulsion

Université Bordeaux 1, Laboratoire CBMN UMR 5248, Talence Cedex, France.
The British journal of nutrition (Impact Factor: 3.45). 11/2010; 105(7):1026-35. DOI: 10.1017/S000711451000454X
Source: PubMed


The bioavailability of α-linolenic acid (ALA) from flaxseed oil in an emulsified form v. a non-emulsified form was investigated by using two complementary approaches: the first one dealt with the characterisation of the flaxseed oil emulsion in in vitro gastrointestinal-like conditions; the second one compared the intestinal absorption of ALA in rats fed the two forms of the oil. The in vitro study on emulsified flaxseed oil showed that decreasing the pH from 7·3 to 1·5 at the physiological temperature (37°C) induced instantaneous oil globule coalescence. Some phase separation was observed under acidic conditions that vanished after further neutralisation. The lecithin used to stabilise the emulsions inhibited TAG hydrolysis by pancreatic lipase. In contrast, lipid solubilisation by bile salts (after lipase and phospholipase hydrolysis) was favoured by preliminary oil emulsification. The in vivo absorption of ALA in thoracic lymph duct-cannulated rats fed flaxseed oil, emulsified or non-emulsified, was quantified. Oil emulsification significantly favoured the rate and extent of ALA recovery as measured by the maximum ALA concentration in the lymph (Cmax = 14 mg/ml at 3 h in the emulsion group v. 9 mg/ml at 5 h in the oil group; P < 0·05). Likewise, the area under the curve of the kinetics was significantly higher in the emulsion group (48 mg × h/ml for rats fed emulsion v. 26 mg × h/ml for rats fed oil; P < 0·05). On the whole, ALA bioavailability was improved with flaxseed oil ingested in an emulsified state. Data obtained from the in vitro studies helped to partly interpret the physiological results.


Available from: Maud Cansell, Jan 02, 2014
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    • "A poor water solubility of these compounds causes enormous difficulties in delivering them in food. The delivery of such oil-based bioactives/nutraceuticals as emulsions is wellknown (Garti & Yuli-Amar, 2008; Couedelo et al., 2011). Conventionally , food emulsions (O/W) are obtained using high shear mixtures such as UT and piston homogenizers with the assistance of emulsifiers and stabilizers to achieve considerable emulsion stability upon storage (Dapcevic Hadnadev, Dokic, Krstonosic, & Hadnadev, 2013; Maali & Mosavian, 2013; Santana, Perrechil, & Cunha, 2013). "
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    ABSTRACT: This study reports the incorporation of 7–21% of flax seed oil in pasteurized homogenized skim milk (PHSM) using high intensity ultrasound (US) at 20 kHz between 1 and 8 min and at varying power levels. A minimum process time of 3 min at an applied acoustic power of 176 W was sufficient to produce emulsion droplets (7% oil) with an average mean volume diameter of 0.64 μm and they were stable at least 9 days at 4 ± 2 °C. The mechanical, cavitational and cavitation-after-effects of US are responsible for the production of smaller sized emulsion droplets and process-induced modifications of milk proteins. A very small proportion (less than 20%) of partially denatured whey proteins provided stability to the emulsion droplets. The emulsion droplets also showed a surface potential of about −30 mV due to the adsorbed proteins, which provided further stability to the emulsion droplets due to electrostatic repulsion. In order to see if other high shear techniques can generate stable emulsions, experiments were carried out using Ultraturrax (UT) at similar energy densities to that of US. UT did not produce stable emulsions until 20 min of processing suggesting the superiority of US emulsification process.
    Food Hydrocolloids 08/2014; 39:151–162. DOI:10.1016/j.foodhyd.2014.01.006 · 4.09 Impact Factor
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    • "essential fatty acids due to the smaller particles size of the emulsion that ranged from micro to nano particles (Remington and Beringer 2005). Couedelo et al. (2011) found that ALA bioavailability was improved with the flaxseed oil ingested in an emulsified state. The objectives of this study were to determine the emulsifying capacity of surfactants and proteins in flaxseed oil and the effect of using two mixing devices on the characteristics of flaxseed oil emulsions produced. "
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    ABSTRACT: The emulsifying capacity of surfactants (polysorbate 20, polysorbate 80 and soy lecithin) and proteins (soy protein isolate and whey protein isolate) in flaxseed oil was measured based on 1 % (w/w) of emulsifier. Surfactants showed significantly higher emulsifying capacity compared to the proteins (soy protein isolate and whey protein isolate) in flaxseed oil. The emulsion stability of the flaxseed oil emulsions with whey protein isolate (10 % w/w) prepared using a mixer was ranked in the following order: 1,000 rpm (58 min) ≈ 1,000 rpm (29 min) ≈ 2,000 rpm (35 min) >2,000 rpm (17.5 min). The emulsion stability of the flaxseed oil emulsions with whey protein isolate (10 % w/w) prepared using a homogenizer (Ultra Turrax) was independent of the speed and mixing time. The mean particle size of the flaxseed oil emulsions prepared using the two mixing devices ranged from 23.99 ± 1.34 μm to 47.22 ± 1.99 μm where else the particle size distribution and microstructure of the flaxseed oil emulsions demonstrated using microscopic imaging were quite similar. The flaxseed oil emulsions had a similar apparent viscosity and exhibited shear thinning (pseudoplastic) behavior. The flaxseed oil emulsions had L* value above 70 and was in the red-yellow color region (positive a* and b* values).
    Journal of Food Science and Technology -Mysore- 01/2014; 52(7). DOI:10.1007/s13197-014-1495-3 · 2.20 Impact Factor
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    ABSTRACT: Little is known about the ability of α-linolenic acid (Ln) to remain in the sn-2 position of TG during the absorption process. The goal of this study was to determine the Ln distribution in the lymph (Study 1) and plasma (Study 2) TG of rats fed a single i.g. load of structured TG [300 mg/rat of either oleic acid (O)/Ln/O TG (OLnO) or Ln/O/O TG (LnOO), n = 7 rats]. In an early fraction (3-4 h) of lymph (OLnO group; 100% Ln in the sn-2 position), 46 ± 2% Ln was maintained in this position in lymph TG. There was even less (29 ± 6%) in the last fraction (7-24 h) (P < 0.05). Ln was also found (9 ± 3%) in the sn-2 position of lymph TG in the LnOO group. The Ln content in lymph phospholipids was twice as high in rats when they were fed LnOO (4.2 ± 0.1%) than OLnO (2.3 ± 0.2%) (P < 0.005). Six hours postprandially (Study 2), 21 ± 3% of the Ln incorporated into plasma TG was located in the sn-2 position in the OLnO group compared to 13 ± 2% in the LnOO group (P < 0.001). Overall, these results indicate that the amount of Ln that moved from the sn-2 position of structured TG to the sn-1(3) position of lymph TG increased during absorption. This may account for a substantial hydrolysis of the 2-monolinolenylglycerols in enterocytes, leading to the intramolecular redistribution of Ln in lymph TG and, consequently, in plasma TG.
    Journal of Nutrition 11/2011; 142(1):70-5. DOI:10.3945/jn.111.146290 · 3.88 Impact Factor
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