Refining Of Tomato Seed Oil And The Research Of Unsaponifiables

With the growing of tomato processing industry in our country, providing awealth of domestic oil resources-tomato seeds. The fat content of tomato seedsexceeds10%, which belongs to one of herbal oils. Tomato seed oil can be preparedfrom tomato seed by traditional extraction and crushing method. This paper focuseson a study of tomato seed oil extraction and refining. It was also the first time tostudy on tomato seed oil unsaponifiables and separated the components by TLC. Toprovide a theoretical basis for understanding the expansion and developinghigh-quality of tomato seed oil.The fat content is lower than the bulk of tomato seed oil. Some methods ofpreparation can be assisted during extraction the oil to improve the rate of extraction.The experiments explored the effects of microwave pretreatment on the rate ofextraction preliminarily. The results showed that: moisture content of tomato seedbefore microwave pretreatment had a stranger impact on tomato seed oil extraction,when plus5%water, tomato seed oil extraction rate was the highest.There were many methods to get crude oil, whose quality and appearance can notreach the standard, and need to be refined. The squeezed tomato seed oil was refinedby chemical refining method, including degumming, deacidification, bleaching anddeodorization. The acid value and peroxide value of tomato refined oil reached thenational health standards.Squeezed tomato seed oil was used as the raw material to refine. The losses oflycopene content in oil during refining were measured by spectrophotometry. Resultshows that: lycopene content decreased during refining, and decrease rate inbleaching> neutralization> deodorization. The losses of lycopene content duringneutralization (alkali refining, washing) and bleaching were26.83%and67.73%.During neutralization, while the alkaline concentration raised from8.5%to11.5%,the residual lycopene decreased. During bleaching, lycopene losses increased whilethe amount of clay increased or temperature rose. There was no significant change for residual lycopene after5min when bleaching temperature was100°C and the usageof clay was2%, which meaned the lycopene was removed effectively. Lycopenelossed26.83%while neutralization, which main caused by alkali refining process.Lycopene content of the oil as an indicator, used Box-Benhnken response surfacedesign to optimize the alkali refining process conditions, result showed: alkalirefining temperature41.29℃, alkali concentration8.55%,0.10%over the baseamount of alkali. Lycopene content (Y) and alkali refining temperature (A), alkaliconcentration (B) and ultra-alkali capacity (C) of the quadratic regression modelequation coded as follows:Y=34.68-1.96A+0.48B+0.45C+0.68AB-0.53AC-1.8BC-1.28AC-2.65A2-1.4B2-5.01C2For protecting the lycopene in tomato seed oil，simplified the process likeneutralization, washing and vacuum drying to get purified tomato seed oil. Squeezedtomato seed oil was refined by four processes to get refined tomato seed oil, theprocesses were neutralization, washing, bleaching and deodorization. Physicochemi-cal properties and oxidation stability were compared with those two kinds of oil.Results showed that: purified oil reached the national health standard of vegetable oil(GB/T2716-2008). The UV absorption peaks of squeezed tomato seed oil andpurified oil were the same, both of them had two peaks that were240nm and269nm. But the UV absorption peaks of refined oil were240nm,258nm and267nm.There was no change on component type, though the fatty acid composition had aslight variation. The oxidation stability of purified tomato seed oil was better thanrefined tomato seed oil.Analysed the unsaponifiable ingredients of tomato seed oil by GC-MS. Initially,separated the unsaponifiable matter with thin-layer chromatography (TLC). Theresults showed that:42peaks were isolated from tomato seed oil unsaponifiablematters by GC-MS, and29kinds of that were identified. β-sitosterol was themaximum component with the concent of15.68%. Tomato seed oil unsaponifiablesfraction dissolved in hexane was deposed on silica gel60F254, eluted with hexane-chloroform (7:3,v/v), after solvent evaporation, six bands were evidenced underultraviolet light. Then, extrcted the6isolates from the plate. Scanned the6isolates with UV–visible, showing that6isolates had different maximum absorption peak.