Study On Extraction Of Lycopene And Polysaccharides From Tomato Pomace

Xinjiang is China’s main tomato sauce processing base.According to incomplete statistics,in 2018,the tomato planting area in Xinjiang reached more than 1.1 million mu,and the total tomato sauce production reached 1.0183 million tons.Tomato pomace are leftovers in the production of ketchup,but they are rich in active substances such as lycopene and polysaccharides.Lycopene is a promising natural antioxidant with many functions such as anti-cancer,anti-tumor,anti-aging,etc.It has been widely used in pharmaceutical,cosmetics,health products and other fields.At present,there are many reports on lycopene in tomato pomace,but few reports on other active ingredients such as polysaccharides,proteins,and tomato seed oil.Among them,polysaccharides are essential components in all living organisms and have special activity.Therefore,in this study,tomato pomace was used as the raw material,and the extraction process of lycopene and polysaccharides were studied by used salting-out extraction technology,and the crude extract obtained was preliminary purified to realize the lycopene and polysaccharides one-step extraction and coarse separation.Firstly,enzyme-assisted aqueous two-phase extraction of lycopene and polysaccharides from tomato pomace was studied.The effects of the concentration of solvent and inorganic salt,the number of crushing meshes,the rest time of the material-liquid ratio and the enzymatic hydrolysis factors on the yield of the target product were investigated,and the response surface method was used to optimize the enzyme-assisted aqueous two-phase extraction of lycopene and polysaccharides from tomato pomace.The results showed that when the aqueous two-phase system was consisted of 31%（w/w）ethanol/16%（w/w）dipotassium phosphate,extraction under the conditions of 160 mesh and material-liquid ratio of 1:40g/m L for 90 min.After 2%mixed enzyme（pectinase:bromelain 1:1）hydrolyzed at p H 6.0 and 50℃for 119min,the maximum yields of lycopene and polysaccharide were 15.69 mg/100 g and 77.16 mg/g,respectively.In addition,compared with the solvent method,the crude lycopene extract obtained by enzyme-assisted aqueous two-phase extraction has a better scavenging effect on DPPH·,with an IC₅₀ of3.37μg/m L.Secondly,the main active ingredients of the three liquid phase extraction tomato pomace were studied.The effects of factors such as the concentration of n-hexane,ethanol and inorganic salts on the extraction were investigated.The results showed that when the three liquid phase system consisted of 9%（w/w）n-hexane/33%（w/w）ethanol/17%（w/w）dipotassium phosphate,the effect was the best when the meshing number was 160 mesh and material-liquid ratio of 1:50 g/m L for 90 min.The fourier transform infrared spectroscopy showed that the top phase extracts were all-trans-lycopene;the yields of lycopene and polysaccharides by this method were high than tri-solvent-mediated extraction,ultrasonic and microwave-assisted extraction.Thirdly,enzyme-assisted three-liquid extraction of lycopene and polysaccharides from tomato pomace was studied.The effects of enzyme types and enzymatic conditions on extraction were investigated.The results showed that 2%pectinase was hydrolyzed at p H 6.0,enzymatic hydrolysis for 90 min at 45 ^oC,the maximum yield of lycopene and polysaccharides were 127.0 mg/100 g and 59.8 mg/g,respectively.The functional groups structure of lycopene obtained by EA-TLPE was not destroyed showed by Fourier transform infrared spectrum;the yields of lycopene and polysaccharides by this method are high than enzyme assisted tri-solvent-mediated extraction and the three liquid phase extraction,And better antioxidant activity.Finally,the macroporous resin was used to purify lycopene and polysaccharides crude extracts obtained from enzyme-assisted three-liquid phase.The top phase crude extract was purified by column chromatography;the bottom phase crude extract was purified and the structure was preliminary analyzed,The decolorization effects of AB-8 and D101 resins,the number of protein removals by the Sevage method,the graded sedimentation,and the Congo red experiment were investigated.The results show that 7.8 g of lycopene crystals can be obtained by column chromatography purification of the crude extract of the top phase;the lower phase crude extract was decolorized with AB-8 type macroporous resin,and the effect of removing protein were repeated six times.The mass of P70 component is the largest in the graded sedimentation experiment.and Congo red experiment showed that the tomato polysaccharides had a stable triple helix structure.