Extraction Process Of Iron Walnut Oil And Preparation Of Its Liposomes And Oleogels

Iron walnut is one of the major walnut species in China,with wide distribution,large yield,easy to grow and store,high nutritional value and broad commercial prospects.However,due to the lack of iron walnut processing products,many iron walnut resources cannot be effectively utilized,resulting in waste.Therefore,in order to expand the application of iron walnut,this thesis developed a series of iron walnut primary and further processed products,including iron walnut liposome and iron walnut oil gel,by improving the quality and extraction rate of iron walnut oil with iron walnut as raw material,and the experimental results are as follows:First,iron walnut oil was prepared by leaching,ultrasonic leaching and microwave leaching using iron walnut as raw material to compare its physicochemical properties,fatty acid composition,tocopherol content and antioxidant capacity,and the best quality iron walnut oil processing technology was optimized by principal component analysis and single-factor-orthogonal experiment.The experimental results showed that the acid value(0.35-0.49 mg/g),peroxide value(0.02-0.04 g/100g)and fatty acid composition of iron walnut oil prepared by the three processes were similar and met the requirements of national standards.Iron walnut oil prepared by microwave leaching had the highest α-tocopherol content(16.81 mg/kg)and total phenol(15.37 mg/kg),and the highest antioxidant capacity of nonpolar DPPH(502.60μmol TE/kg),whole oil DPPH(774.40 μmol TE/kg),FRAP(175.96 μmol TE/kg)and ABTS(146.60 μmol TE/kg)had the highest free radical scavenging ability and were the best processing methods.The optimal extraction conditions were obtained after optimization as follows: number of extractions 4 times,material-liquid ratio 1:8 g/m L,extraction temperature 60 °C,and extraction time 2 h.Under these process conditions,the extraction rate of iron walnut oil reached 66.64%.Next,β-sitosterol was used instead of cholesterol for the preparation of iron walnut liposomes,and the process conditions were optimized by single-factor-response surface experiments with the encapsulation rate and particle size as the optimization objectives.The optimum liposome preparation conditions were: soy lecithin concentration was 8.7 mg/m L,the mass ratio of soy lecithin toβ-sitosterol was 6:1 g/g,the mass ratio of soy lecithin to iron walnut was 4:1 g/g,the content of Tween-80 was 20%,the sonication time was 30 min,and the sonication power was 400 W.Under these conditions,the liposomes of iron walnut appeared sphere-like with smooth and complete appearance.Under these conditions,the liposomes of Fe-N are spherical in shape,smooth and intact,with 92.51%encapsulation rate,137.63 nm particle size,-39.93 m V zeta potential and 0.25 PDI,which have high encapsulation rate,small particle size,uniform and stable distribution.Finally,six types of oleogels were prepared from iron walnut oil using glutelin/β-sitosterol,glutelin/cholesterol,monostearic acid glycerides,monoglycerides/beeswax,beeswax,and carnauba wax as raw materials,and the fatty acid composition,antioxidant capacity,textural properties,rheology,oil-holding properties,crystal properties,and chromaticity of the oleogels were compared to investigate the effect of the type of gelling agent on the structural properties of iron walnut oil gels The results of the experiments showed that the gels of iron walnut oil were not suitable for the analysis.The experimental results showed that the fatty acid composition of the oleogels prepared from iron walnut oil did not change,and the intermolecular forces and crystal self-assembly structures of the gels prepared from different oleogel agents were different.The oleogels prepared by glutelin/β-sitosterol mainly consisted of carbonyl and carboxyl groups forming a hollow wedge structure by intermolecular hydrogen bonding and stacking with each other,and their free radical scavenging ability(766.50 μmol TE/kg)and total phenolic content(14.98mg/kg)of DPPH whole oil showed almost no loss compared with that of iron walnut oil,and excellent hardness(1116.51 g)at 4 ° C.Monoglycerides and monoglycerides/beeswax mainly formed reverse bilayers in hydrophobic medium and accumulated continuously to form a three-dimensional mesh structure.The addition of beeswax made the three-dimensional mesh structure more dense,with an oil-holding capacity of 98.84% and a moderate hardness of 109.94 g,making it suitable as a spreadable solid fat.In summary,this experiment prepared the processing process of iron walnut oil by microwave leaching and optimized the process conditions to improve the extraction rate.Using iron walnut oil as raw material,two products of iron walnut oil liposome and iron walnut oil gel were studied and developed,which provided theoretical guidance for the development and utilization of iron walnut.