Investigation of physicochemical and biological properties of bacterial cellulose & zein-reinforced edible nanocomposites based on flaxseed mucilage containing Origanum vulgare L. essential oil.

In the present study, the effect of zein and different amounts of bacterial cellulose (BC; 1, 2 and 3 wt%) on the physical, mechanical and barrier properties of flaxseed mucilage/carboxymethyl cellulose (FM/CMC) composite was investigated. The appearance of the absorption band at 1320cm-1 in the ATR-FTIR spectra of nanocomposites indicated the successful introduction of zein into their structure. The characteristic peak at 2θ of 9° belonging to zein disappeared in XRD patterns of the prepared composites suggesting the successful coating of zein via hydrogen bonding interactions. SEM images proved the formation of semi-spherical zein microparticles in the FM/CMC matrix. TGA plots ascertained the addition of zein and nanocellulose caused a significant increase in the thermal stability of FM/CMC film, although zein showed a greater effect. The presence of zein and nanocellulose increased the mechanical strength of nanocomposites. The WVP of FM/CMC decreased after the incorporation of zein and nanocellulose, which created a tortuous path for the diffusion of water molecules. The zein particles exhibited a greater influence on improving the mechanical and barrier properties compared to nanocellulose. FM/CMC-Z film exhibited the highest mechanical strength (49.07 ± 5.89 MPa) and the lowest WVP (1.179 ± 0.076). The composites containing oregano essential oil (EO) showed higher than 60 % antibacterial properties. The bactericidal efficiency of FM/CMC/Z-EO and FM/CMC/Z-EO/BC1 nanocomposites decreased about 10% compared to FM/CMC/EO and FM/CMC-Z/BC1. This evidenced the successful encapsulation of EO molecules in zein particles. According to the in vitro release study, entrapment of EO into zein particles could delay the release and provide the extended antimicrobial effect.

Effect of thymol and Pickering stabilization on in-vitro digestion fate and oxidation stability of plant-derived flaxseed oil emulsions.

The aim of this study was to evaluate the effect of Pickering stabilization by biopolymer-based particles (bioparticles), consisting of flaxseed protein and polysaccharides, and of the addition of thymol to the oil phase on the oxidation stability, and digestion fate of flaxseed oil (FO) emulsions, compared to bulk FO and conventional emulsions stabilized by polysorbate 80 (PS80). Applying Pickering stabilization and thymol simultaneously was a successful approach to retard FO oxidation. Moreover, lipid digestion was slower in bioparticle-stabilized emulsions compared to PS80 stabilized emulsions. The thymol bioaccessibility increased after incorporation into FO Pickering emulsions in comparison to the bulk oil. The results suggested that the combination of Pickering stabilization and thymol addition to the oil phase can be used as a promising way of protecting highly unsaturated oils such as FO against oxidation. These emulsions are also applicable for designing functional foods with controlled lipid digestion.

Dual effectiveness of Flaxseed in constipation and diarrhea: Possible mechanism.

ETHNOPHARMACOLOGICAL RELEVANCE: This study was planned to assess pharmacological basis for the medicinal use of Flaxseed in constipation and diarrhea. MATERIALS AND METHODS: The oil and mucilage of Flaxseeds were studied for their laxative, and antidiarrheal activities in mice. The mechanisms of laxative and antidiarrheal activities were further studied using the isolated tissue preparations (rabbit jejunum and guinea-pig ileum) immersed in Tyrode׳s solution maintained at 37°C and aerated with carbogen gas. Isotonic responses were measured on spontaneously contracting isolated jejunum and guinea-pig ileum preparations. RESULTS: Oral administration of Flaxseed oil (30 and 70mg/kg, orally) and mucilage (1 and 2.5g/kg, orally) caused dose-dependent increase in wet feces in mice. The spasmogenic effect of Flaxseed oil was partially blocked by pyrilamine (p<0.05) and atropine (p<0.01) in isolated rabbit jejunum whereas atropine completely blocked the effect of Flaxseed mucilage on isolated guinea-pig ileum. When studied for its antidiarrheal effect, Flaxseed oil reduced the castor oil-induced diarrheal score by 49.35% and 84.41% and intestinal secretions by 19% and 33.62% at the oral doses of 100 and 300mg/kg respectively. In isolated rabbit jejunum preparations, Flaxseed oil produced a dose-dependent inhibition of both spontaneous and low K(+) (25mM) -induced contractions in rabbit jejunum. The inhibitory effect against low K(+) was most sensitive to tetra-ethylammonium chloride, a non-specific K(+) channel blocker, followed by glibenclamide, a partial ATP-dependent K(+) channels blocker and 4-Aminopyridine, a voltage gated K(+)-channel blocker. CONCLUSIONS: Our results indicate that Flaxseed oil and mucilage exhibit laxative activity, mediated primarily through cholinergic pathway with weak histaminergic effect component evident in Flaxseed oil, which also showed antidiarrheal activity, mediated possibly through K(+) channels activation. Thus this study rationalizes the medicinal use of Flaxseed in both the constipation and diarrhea with sound mechanistic basis.

Characterisation of mucilages extracted from seven Italian cultivars of flax.

The chemical composition, physicochemical, functional and sensory properties of mucilages, extracted from seven Italian flax cultivars, were evaluated. All samples were composed of neutral and acidic sugars, with a low protein content. From the NMR data, a rhamnogalacturonan backbone could be inferred as a common structural feature for all the mucilages, with some variations depending on the cultivar. All the suspensions showed a poor stability, which was consistent with a low zeta potential absolute value. The viscosity seemed to be positively correlated with the neutral sugars and negatively with the amount of proteins. Functional properties were dependent on the cultivar. The sensory analysis showed that most mucilages are tasteless. All these outcomes could support the use of flaxseed mucilages for industrial applications. In particular, Solal and Festival cultivars could be useful as thickeners, due to their high viscosity, while Natural, Valoal and Kaolin as emulsifiers for their good surface-active properties.