Research On Acer-Truncatum Oil Extraction And Its Functional Characteristics

Acer truncatum?A.truncatum?is a native plant widely distributed in China.The major research contents of the thesis are:1)Set up the processing technology of ATO;2)Investigated the physicochemical properties and nutraceutical constituents of ATO with different extraction methods;3)Used ATO as one of the basestock in the margarine application;4)Studied how the hardstock of ATO might alter the physicochemical properties and crystal stability of low saturated fatty acid?SFA?margarine during storage.Extraction of ATO and its functional characteristics were studied in order to provide a thorough theoretical basis for margarine applications.The results are as follows:1)The seeds of Acer truncatum from Jinyang ShaanXi Province was used to obtain fully refined ATO.Soxhlet extraction,supercritical carbon dioxide?SC-CO₂?and sub-critical fluid extraction technology were used to extract oil from Acer truncatum seeds.ATO was extracted with petroleum ether?60⁹0??using a Soxhlet apparatus for 6 h.The residual solvent was removed at 90?under reduced pressure with a rotary evaporator.The SC-CO2 extraction was carried out in a 100 mL stainless steel vessel.The optimal parameters were determined to be 39 MPa,44?and 10 h resulting in a maximum yield of 43.1%.The optimal conditions of extraction of ATO by sub-critical fluidextraction technology were:40?,Kernel:solvent=1:3?g:mL?for 3 times,and 30 min for each extraction,with a yield of 43.6%.Refined ATO was obtained by enzymatic degumming,bleaching and deodorization processing.2)ATO rich in nervonic acid was extracted using supercritical carbon dioxide.Gas chromatography?GC?analysis revealed that the oil contained approximately 6.22%nervonic acid.The sn-2 compositions were also determined using lipase hydrolysis.A total of 52 triacylglycerides?TAGs?were tentatively identified in the oil using an ultra-performance convergence chromatography?UPC2?coupled with quadruple time-of-flight mass spectrometry?Q-TOF-MS?for the first time.In addition,the contents of phytosterols?1961.9²402.8?mol/kg?and?-carotene?2.09².35?mol/kg?were also quantified for the first time,along with tocopherols?2352.0²654.3?mol/kg?.?-tocopherol?1296.9¹442.3?mol/kg?was the primary tocopherol,while?-sitosterol?1355.2¹631.3?mol/kg?was the dominant phytosterol.The physicochemical properties of the oil were also investigated.This study indicated that Acer truncatum seed oil is rich in nervonic acid and other nutraceutical constituents.It has a high potential in functional foods for improving human health.ATO contained more than 92%unsaturated fatty acid,and NA is one of the long mono-saturated chain fatty acids,which has a great potential in trans-free and low saturated fatty acid margarine manufacturing.Furthermore,ATO contains 33.7%LCFA,which may improve the stability of margarine products during storage.3)Obtained trans-free fats containing nervonic acid,a fatty acid with beneficial effects for mental health.Four fats containing 1.28².41%?w/w?nervonic acid were prepared by chemical or enzymatic interesterification of palm stearin?ST?,Acer truncatum oil?ATO?and palm kernel oil?PKO?.The chemical procedure was catalyzed using MeONa,whereas the enzymatic procedure was catalyzed with a 1,3-specific lipase.As a result,the interesterified fats showed a similar fatty acid profile to their corresponding physical blends measured by gas chromatography,but contained more nervonic acids at the sn-2 position,which was more conducive to metabolism and absorption.The content of tripalmitoylglycerol?PPP?and 1,3-dipalmitoyl-2-oleoyl glycerol?POP?or1,2-dipalmitoyl-3-oleoyl glycerol?PPO?in the interesterified fats decreased significantly,resulting in improved plasticities.All interesterified fats showed a satisfactory content of tocopherols and oxidative stability.A combination of differential scanning calorimetry,X-ray diffraction spectroscopy and polarized light microscopy results suggested that the interesterified fats formed spherulitic,needle-like crystals in the?'form,while the physical blends formed dendritic crystals in the?form.These data indicated that the trans-free interesterified fats rich in nervonic acid might have a great potential in margarine applications.4)The effect of long chain fatty acid esters on crystallization stability of margarine and the potential mechanisms were investigated using shelf life evaluation methods.ATO contains 33.7%LCFA with C20,C22 and C24chains,which is higher than in normal vegetable oil with about 3%LCFA.The margarine system with fully hydrogenated Acer truncatum oil?FHATO?containing LCFA shows?'crystal tendency during storage after 6 cycles of temperature fluctuation experiments,demonstrating that it may be most suitable for margarine use.TAG structure,melting point,storage temperature and fatty acid composition are contribution factors for the crystallization of hard stocks.ATO with LCFA has a similar amount of saturated fatty acids TAG as PSS and PPS,with a high melting point,and diversified fatty acid composition,which can help to produce and maintain the beneficial?'crystallization forms in the margarine during storage.