Effect of chia mucilage addition on oxidation and release kinetics of lemon essential oil microencapsulated using mesquite gum - Chia mucilage mixtures.

Lemon essential oil (LEO) emulsions were prepared using mesquite gum (MG) - chia mucilage (CM) mixtures (90-10 and 80-20 MG-CM weight ratios) and MG as control sample, LEO emulsions were thenspray dried for obtaining the respective microcapsules.LEO emulsions were analyzed by mean droplet size and apparent viscosity, while microcapsules were characterized through mean particle size, morphology, volatile oil retention (≤51.5%), encapsulation efficiency (≥96.9%), as well asoxidation and release kinetics of LEO. TheLEO oxidation kinetics showed that 90-10 and 80-20MG-CM microcapsules displayed maximum peroxide values of 91.6 and 90.5 meq hydroperoxides kg-1 of oil, respectively, without significant differences between them (p > .05).MG-CM microcapsules provided better protection to LEO against oxidation than those formed with MG; where the oxidation kinetics were well adjusted to zero-order (r2 ≥ 0.94).The LEO release kinetics from microcapsules were carried out at differentpH (2.5 and 6.5) and temperature (37 °C and 65 °C) and four mathematical models (zero-order, first-order, Higuchi and Peppas) were used to evaluate the experimental data; the release kinetics indicated that the 80-20 MG-CM microcapsules had a longer delay in LEO release rate, followed by 90-10 MG-CM and MG microcapsules, hence, CM addition in MG-CM microcapsules contributed to delay the LEO release rate. This work clearly demonstrates that use of a relatively small amount of CM mixed with MGimproves oxidative stability and delays the release rate of encapsulated LEO regarding MG microcapsules, therefore, MG-CM mixtures are interesting additives systems suitable for being applied in food industry.

Identification of Tequila with an Array of ZnO Thin Films: A Simple and Cost-Effective Method.

An array of ZnO thin film sensors was obtained by thermal oxidation of physical vapor deposited thin Zn films. Different conditions of the thermal treatment (duration and temperature) were applied in view of obtaining ZnO sensors with different gas sensing properties. Films having undergone a long thermal treatment exhibited high responses to low ethanol concentrations, while short thermal treatments generally led to sensors with high ethanol sensitivity. The sensor array was used to distinguish among Tequilas and Agave liquor. Linear discriminant analysis and the multilayer perceptron neural network reached 100% and 86.3% success rates in the discrimination between real Tequila and Agave liquor and in the identification of Tequila brands, respectively. These results are promising for the development of an inexpensive tool offering low complexity and cost of analysis for detecting fraud in spirits.

Relationship between the elemental composition of grapeyards and bioactive compounds in the Cabernet Sauvignon grapes Vitis vinífera harvested in Mexico.

The red grape Vitis vinífera is an important source of phenolic compounds, which can prevent disease if included as a part of a diet. The levels of these compounds in grapes have been associated with various environmental factors, such as climate, soil composition, and biotic stress. The purpose of this study was to determine the relationship between the elemental compositions of the soil and the grapes and the presence of bioactive compounds, such as catechin, epicatechin, piceid and resveratrol. Ethanol-based extracts of red grapes were used to quantify total and individual phenolic compounds by HPLC. It was observed that the elemental compositions of the soil and the grapes were related to their locations within different wine-producing regions. A principal component analysis showed a relationship between high metal content (Sr, Mn, Si and Pb) and higher concentrations of antioxidants in the grapes.