Effect Of Processing On The Stability And Isomerization Of Lycopene

Lycopene is a functional factor with superior physiological functions.The cis-isomer has better bioavailability and biological activity than the naturally occurring all-trans,but it is prone to oxidative degradation and cis to all-trans recovery.Conversion,stability is not good.In this paper,YMC Carotenoid C30 column was used as the mobile phase with methyl tert-butyl ether and methanol as mobile phase.A gradient elution HPLC system achieves good separation of lycopene isomers.This method can be used for quantitative analysis.The linear regression equation of all-trans lycopene is y=24946.91x(R2=0.9987).The identification of lycopene isomers was combined with mass spectrometry information and UV spectral information.A total of 12 lycopene isomers including all-trans lycopene were detected.Tomato sauce processing industry is a characteristic representative industry in China,and its quality index is directly affected by the quality of raw materials.For the first time,the lycopene content of 44 tomato varieties cultivated in Xinjiang,which is the main producing area of tomato,was studied in order to study the mutual transformation of lycopene and its isomers during the processing of new breeding tomatoes and to evaluation stability and functionality.The early tomato cultivar NDM2272(PT-6)had the highest lycopene content and total cis lycopene content,1.28 and 0.18 mg/g,respectively,and was not significantly degraded after simulated industrial sauce.The highest lycopene content of late-maturing tomato cultivar was Jinfan 7(PT-26),while the best cultivar of lycopene and its isomers was H9888(PT-33).Compared with early-maturing tomato varieties,late-ripening tomato sauces are more prone to degradation.The decrease in lycopene content of Jinfan No.15 and H9997 reached 76.15 and 68.9%,respectively,and the total cis-lycopene content decreased by 56.3% and 54.5% are not suitable for processing into tomato products.The lycopene content of different varieties of processed sauces remains different,and changes in the processing parameters provide the basis for the industry.Tomato sauce is the main processed product of tomato.It is of great significance to study the effect of concentrated production process on the conformation of lycopene in fruit.According to the rate of change of lycopene molecules in the process of concentration,the stability of each component can be judged as follows: 9-cis lycopene>13-cis lycopene>9,13-dicis lycopene >15-cis lycopene.The effect of concentration time on the isomerization of lycopene is more pronounced than the concentration temperature.Due to the presence of long chains of conjugated carbon-carbon double bonds,lycopene is prone to chemical changes when exposed to light and heat,lycopene is very sensitive to light,and different frequencies of light have different effects on lycopene.By studying the effects of four different illumination conditions(white,red,blue,and red)on the time and the conversion of lycopene and its isomers in lycopene oil,it was found that the red and green light were on lycopene and its isomers.The retention effect is better,and blue light degrades rapidly completely.The effect of heat treatment conditions on the conformation of lycopene at temperature(40,50,60,and 70?)and time(1,2,3,4 and 5 h),elucidation of the effect of heating process on the conformation of lycopene,and construction of heat The degradation kinetics,the lower the temperature,the shorter the time,the smaller the absolute value of the degradation rate constant,the more stable the lycopene.By calculating the apparent activation energy of degradation of lycopene,the stability of all-trans lycopene is best.