热处理对不同颜色番茄中类胡萝卜素异构化和降解的影响

Effect of Thermal Processing on Degradation and Isomerization of Carotenoids in Colored-Tomatoes

为综合利用彩色番茄资源,对比不同颜色番茄中类胡萝卜素的组成,研究类胡萝卜素热稳定性,阐述其异构化和降解的规律。利用高效液相色谱-二极管阵列检测器(HPLC-PDA)并配备YMC Carotenoid C30色谱柱分离类胡萝卜素,并以光谱特征鉴定异构体,系统分析番茄中类胡萝卜素组成,并探究热处理温度和时间对其类胡萝卜素异构化和降解的影响。结果表明,橙色番茄-1富含顺式番茄红素(主要为7Z,9Z,7’Z,9’Z-番茄红素),橙色番茄-2以全反式(all-E)β-胡萝卜素为主,而常见的红番茄则富含all-E-番茄红素。橙色番茄-1的顺式番茄红素质量分数分别是橙色番茄-2和红番茄的28.79倍和12.57倍,六氢番茄红素和八氢番茄红素质量分数分别是橙色番茄-2和红番茄的7.52倍和3.20倍。橙色番茄-1中的番茄红素质量分数随热处理时间(0~5 h)延长和温度(60~100℃)升高,呈明显下降,100℃下3 h后降至初始值的1/3;其中,7Z,9Z,7’Z,9’Z构型在100℃时降至未检出,而all-E、5-顺(5Z)和其他顺式质量分数分别增至28.51%、28.73%和42.76%。热处理对橙色番茄-2和红番茄中番茄红素和β-胡萝卜素的降解和异构化无显著影响(P>0.05)。此外,橙色番茄-1中六氢番茄红素和八氢番茄红素经100℃处理3 h后保留率仍达到84.32%和88.76%。以上表明,橙色番茄-1是高顺式番茄红素、六氢番茄红素和八氢番茄红素的良好来源。7Z,9Z,7’Z,9’Z-番茄红素热稳定性差于all-E-番茄红素和all-E-β-胡萝卜素;六氢番茄红素和八氢番茄红素热稳定性良好。以上信息对综合利用不同颜色的番茄原料和研发高生理活性的番茄产品具有重要意义。

In order to comprehensively utilize the colored tomatoes,the carotenoid compositions of tomatoes in different colors were compared.The thermal stability of carotenoids was assessed,and the rules of isomerization and degradation were discussed.High-performance liquid chromatography-diode array detector(HPLC-PDA)with YMC Carotenoid C30 column was employed to separate carotenoids from tomatoes,and individual isomers were identified by the spectral characteristics.In addition,the effects of thermal treatment on the isomerization and degradation of carotenoids were investigated.The results showed that orange tomato-1(OT-1)was rich in cis-lycopene(mainly 7,9,7’,9’-tetra-cis(7Z,9Z,7’Z,9’Z)),while orange tomato-2(OT-2)was abundant in all-trans-(all-E-)β-carotene.The red tomato was rich in all-E-lycopene.The cis-lycopene content of OT-1 was 28.79 times and 12.57 times of that in OT-2 and red tomato,respectively.The total amount of phytofluene and phytoene was 7.52 times and 3.20 times of that in OT-2 and red tomato,respectively.In OT-1,the lycopene concentration decreased with the increment of heat time(0~5 h)and temperature(60~100℃).The value decreased to 1/3 of the initial content after treated at 100℃for 3 h.Meanwhile,the 7Z,9Z,7’Z,9’Z isomer reduced significantly,which was not detected when treated at 100℃.However,the all-trans(all-E),5-cis(5Z)and other cis-lycopenes increased to 28.51%,28.73%and 42.76%,respectively.Heat treatment had no significant effect on the degradation and isomerization of lycopene andβ-carotene in OT-2 and red tomato(P>0.05).Besides,the retention rates of phytofluene and phytoene in OT-1 after treatment at 100℃for 3 h still reached 84.32%and 88.76%.The results indicated that OT-1 was good source with high contents of cis-lycopene,phytofluene and phytoene.7Z,9Z,7’Z,9’Z-lycopene was less thermally stable than all-E lycopene and all-E-β-carotene,while phytofluene and phytoene showed better thermal stability.The above information is of great significance for the comprehensive utilization of tomato sources in different colors and the development of tomato products with high bioactivity.