Study On The Compability Of Lard And Palm Oil And Its Application

Lard oil (LO) and palm oil (PO) are most common animal fat and vegetable oil,respectively. Combination of lard with palm oil can be used to improve the processingperformance of the two kinds of oils, and keep the flavor at the same time. However,combination of different kind of oils with each other will lead to the change in fatcrystallization characteristics. resulting in incompatible phenomenon, which affects oil foodprocessing, quality and shelf life. In this study, the focuses will be put on the compatibility ofmixture system between lard and palm oil in order to provide the basis for their application inspecial oil.Firstly, LO was mixed with six kinds of palm fractions (25.8℃,30.9℃,32.3℃,34.9℃,46.2℃and53.1℃PO). The compatibility of the binary systems was studied by usingisothermal lines (SFC-T) and deviation curves (△SFC-T). The results showed that when LOwas mixed with46.2℃PO at the temperature range from0～40℃, compatibility was thebest. Only slightly monotectic or eutectic phenomenon was observed, followed by53.1℃palm oil. constantly monotectic phenomenon was found at0～40℃when mixing with53.1℃palm oil. The optimal ratio for the compatibility between LO and34.9℃PO wasobserved at0.2:0.8. The same ratio was obtained when LO was mixed with32.3℃PO. Theoptimal ratio for compatibility of LO and30.9℃PO was0.9:0.1. Finally, when LO wascombined with25.8℃PO, the optimized value was observed at0.2:0.8.Subsequently, another PO was added into a binary mixtures of LO＋46.2℃PO, or LO＋53.1℃PO. The compatibility of ternary system was investigated by using mixingregression method. The results showed that the compatibility was further improved afteradding the third oil. The ternary mixtures of LO＋46.2℃PO＋53.1℃PO had the bestcompatibility, and the optimal proportion was0.1:0.45:0.45. Its△SFC values were varidedwithin±1.5%at0～40℃. In addition, other systems with specific proportion and temperaturerange also had a good compatibility. For example the optimal proportion of the ternarymixtures of LO＋24.2℃PO＋46.2℃PO was0.1:0.1:0.8, and its△SFC values werevaried within±1.5%at the temperature from20to40℃.Finally, Based on the compatibility and requirements for SFC and crystal type of theplasticity of shortening, the ternary mixtures of LO＋24.2℃PO＋46.2℃PO withproportion of0.1:0.1:0.8was selected, whereas the proportion of LO＋46.2℃PO＋53.1℃PO was0.1:0.45:0.45. The trial experiments of shortening using sealed continuous processingmode with freezing, crystallizing and plasticizing (Votaor process) was conducted. The resultsshowed that the two shortening products have a wide range of plasticity, with SFC valuesrange within32.60%～78.10%and23.50%～71.30%, respectively, They could be used inshortening due to the formation of stable β’ type. No significant difference was observed inthe bread mading of the two kinds of shortening compared to the bread mading of commercialshortening. In addition, self-making bread had a larger volume than those making of LO and was more delicious and softer than those mading of PO. The optimal formula for frozen foodoil was LO:21.9℃PO:53.1℃PO＝0.45:0.1:0.45. The trail production showed that theoptimal formula had a wider plasticity range(SFC values range in8.60%～65.40%, at10～35℃) than LO (SFC values range in6.03%～52.63%, at10～35℃). Additionally, itshardness was between LO and PO. Dumplings making of optimal formula showed nosignificance difference with those making of LO (p＞0.05).