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Nutrients are biochemicals essential to the human body for growth and survival. They are included in different foods in various proportions and quantities, and are released after food metabolism. The factors that produce physicochemical changes on nutrients are light, temperature and oxygen. Unwanted changes in visual (color) and olfactory (smell) effects, which are easy to spot, are not accepted by consumers and are used as indicators of inferior or unsafe products. The combined effects of the loss of nutrients and bioactive components, with the degradation of quality (color and flavor), negatively affect the overall quality of food and consumer acceptance, leading to lower product sales, lower brand confidence and an economic loss in the food industry. Heat processing of food can affect the bioavailability of minerals in their composition by changing their solubility and destroying food constituents that increase or decrease availability. Cooking and baking can destroy some of the valuable nutrients in food: polyunsaturated fatty acids, proteins, carbohydrates, vitamins. [ABSTRACT FROM AUTHOR]

Thispaper reports experimental data of density and refractiveindex for the binary systems of 1-butyl-3-methylimidazolium tetrafluoroborate,[Bmim][BF4], with 1,4-dioxane, and 1-ethyl-3-methylimidazolium tetrafluoroborate,[Emim][BF4], with 1,4-dioxane and ethylene glycol (EG). Moreover,for the system [Bmim][BF4] + EG we report here refractive index data.The measurements for the systems with EG were made over the entirecomposition range at atmospheric pressure (101 ± 2 kPa) and inthe temperature range from (293.15 to 353.15) K for densities andfrom (298.15 to 323.15) K for refractive indices. Because at roomtemperature the mixtures of both ionic liquids with 1,4-dioxane haveindicated partial immiscibility, liquid–liquid phase equilibriumwas determined. The excess molar volumes, VE, and deviations in refractive index, Δn,were calculated by using the measured experimental data and correlatedby the Redlich–Kister type equations. VEvalues are positive for the system with EG and negative forboth systems with 1,4-dioxane, Δnpresentingan opposite sign. To probe the interactions in mixtures and to correlatethe excess molar volumes of the mixtures the Prigogine–Flory–Patterson(PFP) theory has been used. Moreover, to correlate VEand predict density and refractive index of the mixturesthe Lorentz–Lorenz equation was applied. [ABSTRACT FROM AUTHOR]