| Wax-based oleogel is an organogel formed by wax as a gelator and liquid vegetable oil as a continuous phase.It has the advantages of solid strength and plasticity as well as the reduction of trans fat and saturated fat content in foods.It can be a healthy fat type that can replace traditional solid fat applications.In this paper,beeswax(BW),candelilla wax(CLW),carnauba wax(CRW),and rice bran wax(RBW)were used as gelator.The effects of different lipid matrix saturation,length of carbon chain and type of glyceride on the gel characteristics of wax-based oleogel were analyzed from the critical concentration,oil binding ability(OBC),texture,thermal,microscopic properties and storage stability,To provide basic support for the development of wax based oleogel in food industry.The contents are as follows:(1)Conducted a study on the effect of lipid matrix saturation on the properties of oleogel.The critical concentrations of wax-based oleogels with different saturation were BW: 3%,CLW: 2%,CRW: 4%(RCR: 5%)and RBW: 5%,respectively.The OBC of BW oleogel showed no significant correlation with saturation of lipid matrix.Other oleogel had no correlation,but it could reach 99.90% at high concentration.The texture parameters of BW and CLW oleogel had a weak correlation with the saturation of lipid matrix.The correlation between thermal properties,X-ray diffraction(XRD)and FTIR and saturation of lipid matrix was not observed.It was observed that the thermal parameters of BW oleogels were most similar to CM.Polarizing microscope(PLM)found needle-like crystals of BW and CLW oleogel and spherical crystals of CRW and RBW oleogel.The measurement of peroxide value(PV)showed the dependence on the PV of lipid matrix.(2)The difference analysis of carbon chain length on different wax-based oleogels was completed.The lowest critical concentration of MCT and CLW was 1%,while MCT and BW was 4%,which was greater than that of CO(3%).Except RBW oleogel,the OBC of other wax-based oleogel prepared by MCT was less than CO.In addition to the high texture parameters of MCL with low critical concentration,other MCT oleogels showed weak firmness and stickiness.The thermal profile of CRW oleogel had significant difference with lipid matrix of different chain length.Different thermal parameters and endothermic peaks were observed,and the thermal behavior of BW and RBW oleogel was also different.The crystal size and distribution of wax-based oleogels with different chain lengths were consistent with the results of other properties.The absorption peak of FT-IR was similar to that of lipid matrix,and the stability was also related to the PV of lipid matrix.MCT oleogel was the most stable.(3)The effect of glyceride type of lipid matrix on wax-based oleogel was studied.The critical concentration of diolein(DO)and BW was 2%,while CO was 3%,CLW oleogel was the same,2%.Both CRW and RBW with DO formed weak gels with critical concentrations of 6% and 7% respectively,and their OBC was significantly lower than CO oleogel.The firmness and stickiness of BW and CLW oleogels prepared by DO were greater than that of CO,while CRW and RBW were opposite.Thermal properties have also observed significant differences in CRW and RBW oleogels of different glycerides,and the cooling process of BW oleogels was also different.RBW was curved fibrous in DO,but similar to spherical in CO.The difference between CRW and RBW oleogels prepared by DO in infrared spectra and lipid matrix is not so obvious compared with other oleogels.It was found that the PV of DO oleogel was relatively stable compared with CO due to the low PV of DO.(4)The overall study showed that CLW oleogel exhibited strong gel properties independent of the properties of lipid matrix due to the strong gel ability of CLW,which showed the lowest critical concentration,the largest firmness and stickiness.The OBC of all samples can reach 99.90% at low concentration,their ?? crystal form has the strongest plasticity and has good solid fat substitution properties. |
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