Physical Properties of Candelilla Wax, Monoacylglycerols, and Fully Hydrogenated Oil Oleogels

Abstract

Oleogels have been studied in the past decade due to their potential to replace saturated fat in foods. Oleogelators have been mostly studied alone or in binary systems. Sometimes a single oleogelator cannot achieve all the technological properties necessary for a specific food application. Thus, the aim of this work was to investigate the interaction between candelilla wax (CLX), monoacylglycerols (MAG), and a fully hydrogenated oil (hardfat [HF]) in soybean and high‐oleic sunflower oils and to evaluate their physical properties. The concentration of the total oleogelator was between 5% and 10%, from pure CLX (5%), sample OP, up to many combinations of MAG, HF, and CLX samples O1, O2, O3, O4, O5, and O6. Samples were evaluated according to their microstructure, melting properties, rheological behavior, hardness, oil‐binding capacity (OBC), and thermal stability. Results showed that the addition of MAG and HF to CLX created a softer gel but improved its rheological properties. Changes in the physical properties were related to the various proportions of CLX, MAG, and HF rather than the overall concentration of structuring agents. For example, for a total concentration of 5% of the structuring agent, a decrease in the CLX concentration from 5% to 3% and the addition of HF and MAG resulted in a softer crystalline network. Increasing the overall concentration of oleogelators by increasing the amount of HF and/or MAG and maintaining the concentration of the CLX constant did not improve the hardness of the gel. This study showed that at least 3% of CLX must be added to the system to obtain a semisolid material independently of the amount of MAG and/or HF added.

Use of High‐Intensity Ultrasound to Change the Physical Properties of Oleogels and Emulsion Gels

“…Each oleogelator (CLX, MAG, and HF) was added in the same proportion (2%). Previous experiments in our laboratory have shown that these concentrations of oleogelators result in good oil entrapment but in low hardness (da Silva et al, ). Therefore, these same oleogelators were chosen to test if sonication could improve the hardness of the oleogel.…”

“…The addition of water to form the EG reduced D m ( P < 0.05) and additionally changed the crystal morphology of the samples (EG5 and EG25) in relation to the EG0. Before water addition, spherulite‐shaped crystals were observed but only small needles were observed after water addition (da Silva et al, ). HIU decreased crystal sizes in sample EG0 ( P < 0.05), but did not change the crystals for samples with water addition.…”

“…The analyses were performed at 25°C for 7 days. The oil loss was determined by weighing filter papers and Petri dishes before the sample was placed in the filter paper and after 1 and 7 days of storage (da Silva et al, ). Oil loss was then calculated using Eq.…”

Sonocrystallization as a tool to reduce oil migration by changing physical properties of a palm kernel fat

“…OL and OM are two important methods used to describe the ability of the crystalline network to retain oil (da Pieve et al., 2010; da Silva & Martini, 2019; da Silva et al., 2018, 2019; Jahaniaval, Kakuda, & Abraham, 2002; Kanagaratnam, Enamul Hoque, Mat Sahri, & Spowage, 2013; Maleky, Mccarthy, Mccarthy, & Marangoni, 2012; Marty & Marangoni, 2009). Although both methods measure basically the same thing (ability to retain oil), the mechanism by which the oil is released from the crystalline matrix is not the same.…”

“…The amount of oil that migrated out of the crystalline matrix was quantified by measuring the diameter of the stain of oil on the filter paper expressed in cm. Three different cylinders were prepared for each crystallization condition (da Silva, Arellano, & Martini, 2018). The crystalline material left on the top of the filter paper after the OM experiment was used to evaluate differences in the crystalline material after OM.…”