Use of Rhodotorula minuta Live Cells Hosted in Water-in-Oil Macroemulsion for Biotrasformation Reaction

Progress in Colloid Delivery Systems for Protection and Delivery of Phenolic Bioactive Compounds: Two Study Cases—Hydroxytyrosol and Curcumin

Insufficient intake of beneficial food components into the human body is a major issue for many people. Among the strategies proposed to overcome this complication, colloid systems have been proven to offer successful solutions in many cases. The scientific community agrees that the production of colloid delivery systems is a good way to adequately protect and deliver nutritional components. In this review, we present the recent advances on bioactive phenolic compounds delivery mediated by colloid systems. As we are aware that this field is constantly evolving, we have focused our attention on the progress made in recent years in this specific field. To achieve this goal, structural and dynamic aspects of different colloid delivery systems, and the various interactions with two bioactive constituents, are presented and discussed. The choice of the appropriate delivery system for a given molecule depends on whether the drug is incorporated in an aqueous or hydrophobic environment. With this in mind, the aim of this evaluation was focused on two case studies, one representative of hydrophobic phenolic compounds and the other of hydrophilic ones. In particular, hydroxytyrosol was selected as a bioactive phenol with a hydrophilic character, while curcumin was selected as typical representative hydrophobic molecules.

Veiled Extra Virgin Olive Oils: Role of Emulsion, Water and Antioxidants

This review traces the current knowledge on the effects of various factors and phenomena that occur at interface, and the role of dispersed phase on the physicochemical, sensorial and nutritional characteristics of veiled extra virgin olive oil (VVOO). Since 1994 there have been numerous articles in the literature regarding the peculiar characteristic of unfiltered olive oil, so-called veiled or cloud virgin olive oil. It is a colloidal system (emulsion–sol), where the continuous lipidic phase dispreads mini droplets of milling water, fragments of cells and biotic fraction obtained from oil processing. During storage, the dispersed phase collapses and determines the quality of the virgin olive oil (VOO). The observed phenomena lead to worsening the quality of the product by causing defects such as oxidation of phenols, triacylglycerols hydrolysis and off-flavor formation. The addition of bioactive compounds, such as vitamins, on product based on VVOO, must take into account the eventual synergistic effect of individual substances. The role of the interphase is crucial to the synergic activity of bioactive molecules in improving oxidative stability, sensorial and health characteristics of VVOO.

Antioxidant Effect of Vitamins in Olive Oil Emulsion

In this study, water-in-extra virgin olive oil emulsions were enriched with vitamins. Water-in oil emulsions are heterogeneous systems able to solubilize both hydrophilic and hydrophobic compounds. Thus, hydrophilic vitamin C and lipophilic vitamin E were loaded separately or together in emulsion. A suitable emulsion composition was selected after considering different surfactant (mono and diglycerides of fatty acids, E471; sorbitan monooleate, Span 80; polyoxyethylene sorbitan monooleate, Tween 80) and water concentrations. The most appropriate emulsion, for the high stability, resulted the one containing concentrations of Span 80 1% w/w and water 1% w/w. The antioxidant effect of vitamins in emulsions was studied considering the variation of the peroxide values during storage. The oxidation reaction was slowed down in emulsions containing vitamin C, but it was quickened by the loading of vitamin E for its high concentration. In emulsions containing vitamin E, indeed, the peroxide values were higher than in emulsions prepared in the absence of vitamins or in oil. The antioxidant activity generated by the co-loading of vitamin C and E was very effective to the point that in presence of high amounts of vitamins the peroxide values did not change in about 40 days of storage, due to the vitamin E regeneration by vitamin C.

Red Wine-Enriched Olive Oil Emulsions: Role of Wine Polyphenols in the Oxidative Stability

The benefits associated with the consumption of red wine due to its rich pool of phenolic compounds are well-recognized, thanks to the antioxidant activity related to these kinds of molecules. However, wine drinking should be done in moderation, or is forbidden for some populations for ethnic or religious reasons. One way to still enjoy the advantages of red wine is to use its dry extract. In order to test the ability of the red wine dry extract to reveal its antioxidant activity, it was solubilized in water to produce water-in-oil (W/O) emulsions based on olive oil. After the selection of the right emulsion composition, kinetics of oil oxidation were carried out in oil and emulsions in the presence of an increasing amount of red wine extract, whose presence influenced the rate of oxidation by slowing it down. This behavior was confirmed by monitoring the oxidation reaction in two ways; i.e., with the classical method that consists of the determination of the peroxide value, and with an accelerated test making use of 2,2′-azobis(2,4-dimethylvaleronitrile) (AMVN) and diphenyl1-pyrenylphosphine (DPPP). The first is a molecule that triggers the reaction at 40 °C, and the other is a molecule that by reacting with hydroperoxides becomes fluorescent (DPPP=O). Moreover, by comparing the emulsion structures observed by optical microscopy, no differences in the size of the dispersed aqueous phase were detected with the increase of the wine dry extract, which is an aspect that confirmed that the antioxidant activity was directly proportional to the wine extract concentration, and thus to the phenolic content.

Determination of bisphenol A in red wine using a double vortex-ultrasound-assisted microextraction assay: Role of the interfacial properties

Bisphenol A (BPA) is a synthetic compound broadly used in medical devices as well as in packaging of food and drinks. Recently, BPA toxicity has become of concern to environmental public health. Red wine that is susceptible to BPA contamination is an alcoholic beverage made from yeast fermentation of grapes in the presence of grape skins so as to extract phenolic compounds. The aim of this study was to validate an efficient, low cost, and time-saving method for BPA determination in red-wine beverage. To this end, a rapid and simple microextraction method is here proposed consisting in liquid-liquid separation assisted by a vortex-ultrasound-vortex procedure combined with gas chromatographic analysis (GC-Fid or GC-IT/MS). By means of a comparative study between real red-wine matrix and synthetic hydroalcoholic solutions, different parameters related to the microextraction steps were investigated. The minimal amount of extraction solvent for a given volume of sample was calculated for both the systems. It was demonstrated that for red-wine matrix, the extent of phase separation is strongly affected by some wine constituents and that separation can be tuned by varying the amount of the extraction solvent. This double vortex-ultrasound-assisted method achieved high recovery of BPA and enrichment factor compared with other microextraction methods.