The Effect of Cooling Rate on the Microstructure and Macroscopic Properties of Rice Bran Wax Oleogels

Abstract

The main purpose of this paper is to study the microstructure and macroscopic characteristics of rice bran wax (RBW) oleogels at a cooling rate of 1℃/min and 10℃/min by polarized light microscopy, Xray diffraction, differential scanning calorimetry, texture analyzer, and micro rheometer. The oleogels of soybean oil were prepared by RBW in concentrations of 5%, 7.5%, 10%, 15% and 20% (wt/wt). The results of this study indicated that the concentration of RBW and cooling rates were affected by the crystal size and spatial distribution of these crystals. For the same RBW concentration, oleogels contained smaller crystals when cooled at 10℃/min compared to 1℃/min. And the oleogels obtained at a rate of 10℃/min exhibited a tighter crystal network, lower melting point, harder texture, and energy storage modulus. These results demonstrated the impact of cooling rate on the rheological behavior, nucleation, and crystallization process.

The Influence of Edible Oils’ Composition on the Properties of Beeswax-Based Oleogels

“…According to the classification described in [ 34 ] and the obtained YV values ( Table 3 ), the texture of the three oleogel samples based on FO, SO, and OO can be classified as “satisfactory plastic and spreadable” and the LO oleogels as “very soft, not spreadable.” In particular, this characteristic can be useful when selecting oleogels to replace solid fat in food products, taking into account the individual characteristics of the end product. When analyzing the results of microscopy, where the average crystal length decreases in the series LO > SO > OO > FO, and hardness values, the oleogels with smaller crystals form stronger gels, which also confirms the conclusion put forward in [ 35 ] about the influence of crystal size on the textural properties of oleogels. In our opinion, this pattern may be related to the larger surface area in small crystals.…”

An Attempt to Relate Oleogel Properties to Wax Ester Chemical Structures

“…For stored products, this could mean low cooling rates. In conclusion, the responses of the WE-based oleogels studied at different cooling rates are in line with published data on wax-based oleogels [ 24 , 25 , 44 ].…”

Effect of water content on the physical properties and structure of walnut oleogels

“…S3(a)-(e), † with the increase of water content, the droplets in the oleogel gradually grew larger, and the droplet morphology gradually changed from spherical to non-spherical. 42 When the oil-to-water ratio was 9 : 1, a slight reective phenomenon was observed on the surface, which is consistent with the observed phenomenon in Fig. 1(a).…”