The role of edible oils in low molecular weight organogels rheology and structure.

In this paper, the role of solvent characteristics on the rheological and physicochemical properties of organogels was investigated using different techniques. Vegetable oils, such as rice, sunflower and castor oil were used as solvents, for producing organogels with monoglycerides of fatty acids or a mixture of fatty alcohols (policosanol) as gelators. Moreover, two non-edible oils (silicon and paraffin oil) were also used for analysing the properties of solvents completely different in nature with respect to the edible ones, for a better interpretation of the given results. Organogels were investigated from a rheological point of view and through a microscopic analysis, given by polarised light (POM) and atomic force (AFM) microscopy, and X-rays to study the crystallinity of the system. The IR technique was used to analyse the intermolecular interactions, resulting in interesting information about the effect of oil polarity on the driving forces promoting structuration. This investigation showed that when solvents of a similar chemical nature are used, their physical properties, mainly oil polarity, are strictly related to the properties of the organogel, such as the onset of crystallisation temperature, the stiffness of the final material and its crystallinity. Anyway, these physical parameters seem insufficient to describe properly the role of solvents when oils of a different chemical nature are compared.

Effect of the monostearate/monopalmitate ratio on the oral release of active agents from monoacylglycerol organogels.

The delivery of active agents from organogels is becoming an important topic owing to the possibility of releasing, in a controlled way, lipophilic agents. Controlled release from foods is a topic with increasing relevance owing to the growing industrial interest towards functional or medical foods, i.e. foods containing nutraceutical agents or drugs. Anyway, release properties are related to the rheological properties of organogels, and, therefore, a deep knowledge of their microstructure and physical characteristics is necessary to design carriers with expected release properties. In this work, two low molecular weight gelators (i.e. glycerol monopalmitate, GMP, and glycerol monostearate, GMS) have been investigated using rheology, microscopy and infrared spectroscopy, IR, aiming at understanding the effects of different gelator ratios on organogel properties. It was observed that GMP, within the range of investigated compositions, seems to be more effective in yielding consistent organogels and this effect was related to differences in microstructure with respect to GMS. Their ability to control the oral release of active agents was investigated, in vitro, using a chemotherapeutic drug for adenocarcinoma of the gastrointestinal tract, 5 fluorouracil (5-FU). A physical model based on carrier erosion was used to describe the release data, evidencing a good agreement with experimental values. Among the tested samples it seems that the use of 90% of GMS (over total organogelator content) yields promising results allowing a good partition of the released drug between the gastric and intestinal tracts with the largest value (although lower than 40% of loaded amount) of the total released drug.

The innovative "Bio-Oil Spread" prevents metabolic disorders and mediates preconditioning-like cardioprotection in rats.

BACKGROUND AND AIMS: Obesity is often associated with an increased cardiovascular risk. The food industry and the associated research activities focus on formulating products that are a perfect mix between an adequate fat content and health. We evaluated whether a diet enriched with Bio-Oil Spread (SD), an olive oil-based innovative food, is cardioprotective in the presence of high-fat diet (HFD)-dependent obesity. METHODS AND RESULTS: Rats were fed for 16 weeks with normolipidic diet (ND; fat: 6.2%), HFD (fat: 42%), and ND enriched with SD (6.2% of fat + 35.8% of SD). Metabolic and anthropometric parameters were measured. Heart and liver structures were analyzed by histochemical examination. Ischemic susceptibility was evaluated on isolated and Langendorff-perfused cardiac preparations. Signaling was assessed by Western blotting. Compared to ND rats, HFD rats showed increased body weight and abdominal obesity, dyslipidemia, and impaired glucose tolerance. Morphological analyses showed that HFD is associated with heart and liver modifications (hypertrophy and steatosis, respectively), lesser evident in the SD group, together with metabolic and anthropometric alterations. In particular, IGF-1R immunodetection revealed a reduction of hypertrophy in SD heart sections. Notably, SD diet significantly reduced myocardial susceptibility against ischemia/reperfusion (I/R) with respect to HFD through the activation of survival signals (Akt, ERK1/2, and Bcl2). Systolic and diastolic performance was preserved in the SD group. CONCLUSIONS: We suggest that SD may contribute to the prevention of metabolic disorders and cardiovascular alterations typical of severe obesity induced by an HFD, including the increased ischemic susceptibility of the myocardium. Our results pave the way to evaluate the introduction of SD in human alimentary guidelines as a strategy to reduce saturated fat intake.

Olive oil and hyperthermal water bigels for cosmetic uses.

Bigels are biphasic systems produced with an organogel (or oleogel) and a hydrogel mixed together at high shear rates. These systems are promising for different uses, among them the formulation of new cosmetic matrices for cosmetic agents delivery is under investigation. In the present paper, a common cosmetic formulation for skin care was enriched with increasing fractions of monoglycerides of fatty acids/olive oil organogels, in order to understand the rheology and the microstructure of these systems. Small amplitude oscillation tests, NMR-self diffusion analysis, contrast phase microscopy and electric conductivity confirmed that the addition of the organogel caused a microstructural change of the starting material, which turned from O/W to a more complex system where, probably, a matrix-in-matrix structure is present at the highest fractions of added organogel.