Production of olive oil organogels: influence of carnauba wax concentration on physicochemical properties

Abstract

Edible oils have potential health benefits when compared to saturated and/or trans fats typically used in food products. In order to widen their use as spreadable products, structuring these oils is a requirement. Thus, the aim of this work consisted in the development of an olive-oil organogel, foreseeing its application in the food industry. Olive-oil was used for the production of the organogels, with carnauba wax (CW) as organogelator (1% to 6% (w/w)), solubilized under magnetic stirring (90 °C) and cooled to room temperature. Systems were evaluated regarding oxidation (PV), textural, rheological (flow curves; non-isothermal oscillatory sweeps) and thermal properties. Olive-oil and commercial butter were used as controls. An increase in CW concentration increased the textural parameters. Compared to values of commercial butter, organogels values were lower, indicating a less structured organogel (highest values: firmness of 3.79 N and 10.29 N for organogel and butter respectively; spreadability of 3.17 N/sec and 10.15 N/sec for organogel and butter respectively). Thixotropy, initial viscosity, onset temperature, enthalpy, also showed an increase with increasingly higher CW concentrations. Melting point of organogels was determined and compared with calorimetric analysis. Similar trends were found: an increase in concentration increased the melting point; Regarding oxidative stability (63 days of storage, room temperature, exposed to light), results showed that, while an increase exists, it is within expected values (maximum PV, 1.10 meqO2/kg at 63 days), and all organogel samples were below the PV of olive oil (maximum PV of 1.47 meqO2/kg, at 63 days). Results show that varying gelator concentration, physicochemical properties can be easily changed and tailored, possibly creating a wide range of products. Thus, an industrial application can be easily projected, since olive oil is a healthier alternative to other spreadable products.