Study On The Mechanism Of Pinking Transformation Of Fresh-cut Lily(Lilium Sativum L.)

Fresh lily bulbs have highly nutritional and economic value.During the storage,the pinking would occur on the surface of lily bulbs after fresh-cut process.This paper mainly studied the phenomenon and mechanism of pinking after fresh-cut process.The conclusions were as followed:(1)Study on the pinking condition of fresh-cut lily bulbs.First,various light treatment(blue,green,red,white,and darking),storage temperature(4 °C,20 °C,30 °C),and gas environment(high-oxygen,low-oxygen,air environment.)were conducted.The color attribute(L* value,a* value,b* value,and ?E value)and area of pinkness were measured during the storage period.The area of pinkness increased with the storage time.The pinking required shortest time with blue light treatment,followed by white light,green light,red light,and dark.To compare with light treatment,the storage temperature and air environment had no significant effect.The L*,and b* value shown decreased with storage period,the a*,and ?E value were opposite(p< 0.05).The optimum pinking condition were found that the storage at 4 ? with blue light treatment under air environment.(2)Study on the identification of composition caused pinking in fresh-cut lily bulb.The anthocyanins were identified by UPLC-MS/MS.Fourteen anthocyanins were identified,including Cyanidin(14%),Delphinium(65%),Petunidin(71%)and Peonidin(14%).There were significant differences in the types and contents of anthocyanins with different light treatment.(3)Study on the formation mechanism of the pinking.Based on proteomics,the fresh-cut lily bulbs stored at 0,6,and 15 days under the optimal pinking conditions were selected to compare the proteomics information.There were 672 differential proteins were identified in the 6vs0 samples,288 differential proteins were identified in the 15vs0 samples,and 604 differential proteins were identified in the 15vs6 samples.Through GO enrichment and KEGG functional analysis,the differential proteins obtained from the 6vs0 sample were mainly involved in 85 pathways,of which 119 differential proteins were involved in Metabolic pathways and 83 differential proteins were involved in the Biosynthesis of secondary metabolites.The differential proteins obtained from the 15vs0 sample were mainly involved in 69 pathways.Among them,13 differential proteins were involved in the Flavonoid biosynthesis pathway,and 75 differential proteins were involved in metabolic pathways.The differential proteins obtained from the 15vs6 sample were involved in 96 pathways.Among of them,108 differential proteins were involved in Metabolic pathways and 65 were involved in the Biosynthesis of secondary metabolites.The intersection pathways,which involved in the samples of three groups,included Phenylalanine metabolic pathway,Flavonoid metabolic pathway,and Amino acid metabolic pathway.Flavonoids of pathways,the primary pathway for synthesis of anthocyanins,involved chalcone synthase,chalcone isomerase,and anthocyanins synthetase.The expression level of chalcone synthase,chalcone isomerase,and anthocyanins synthetase increased with pinking.The proteomics results were consistent with the identification of composition caused pinking,which shown that the synthesis of anthocyanin result in pinking.The results could provide theoretical basis for the preservation of lily bulbs.