Effects Of Interesterification On The Physico-chemical Properties Of Palm-based Oils And Its Application In Food Specialty Fats

Food specialty fats are the high end of oil production.The development of plasticity fats based on palm oil modification is a hot topic in food industry.The application of new oil resources and by-products in modified specialty fats can not only improve the physicochemical quality,but also increase the added value of the products.The modification based on solid fat content and oil polymorphism characteristics is the main blending principle at present.In this paper,palm oil was modified with different types of triacylglycerols,and the influence laws of solid-fat content crystallization habit and microstructure changes were discussed,and the potential practical application in this field was also explored.The main results are as follows.1.PMF was interesterified with edible beef tallow?BT?catalyzed using sodium methoxide. The crystallization rates were expedited,and the solid fat content profiles were got smoother with a wider range of plasticity.The bakery properties prepared with this fat were also improved.The mouth-feel and whipping ability were enhanced by solvent fractionation from the CIE-PMF,and the content of sn-2 saturated fatty acids was also increased after fractionation.2.Shea OL as a byproduct of shea butter with a melting point of 25°C was achieved via solvent fractionation.At temperatures above 25°C,Shea OL exhibited good compatibility and could serve as a blending base oil for preparing specialty fats.Containig about 8% DAG,Shea OL as the oil phase was found to significantly improve the oil in water system's stability compared with the control groups of soybean oil and POL towards maintaining the particle size and emulsion stability at high temperatures.3.The CIE reactions between palm oil and different types of oil were studied and it was found that??form was still domonant,and the crystallization rate was increased obviously when interesterified with BT.Adding soybean oil could significantly increase S/U/U in the system.For pure vegetable oil base,the crystallization rate changed slowly and?form was kept dominant.PKO could reduce S/U/U content,and when it acted with soybean oil, PKO showed a stronger ability to S/U/U and enriched the triacylglycerols compositions, especially increasing the C44 triacylglycerols content.The crystallization rate was also expedited,and the product sample was found to tend to be??crystal form.The addition of PMF above 30%could improve the high-temperature solid fat content to expand plasticity range.However,the addition below 30%was ineffective.4.A new and efficient technique was used for the production of DAGs by the esterification of oleic acid with glycerol catalyzed by diatomite-loaded SO₄^2–/TiO₂.Under the optimized conditions,DAGs yield reached about 59.61%with a purity of 69.64%after a one-stage molecular distillation.An enzymatic production of highly unsaturated MDs?HUSMDs?is reported.Oleic acid and corn oil were used to produce HUSMDs in a bubble column reactor system in the presence of Novozyme 435.Under the optimal conditions,the content of HUSMDs in the products was above 82 wt.%.HUSMDs decreased the crystallization rate significantly,and improved stability of?'crystals which also demonstrated the most stable hardness.5.RBW was modified with POL catalyzed by Lipozyme TL IM.The crystallization rates of RBW-based enzymatically interesterified?EIE?products were found significantly higher than both the starting mixture.The EIE RBW-based samples were donminately crystalized in?'form and presented a much smoother solid fat content profile as compared to physically blended raw materials.And RBW-based samples after EIE also showed an increased hardness and comparable surface properties as an interesting plasticity fat substitute.