Qiao Liping, Sun Yujing, Chen Rongrong, Fu Yu, Zhang Wenjuan, Li Xin, Chen Jianchu, Shen Yan, Ye Xingqian
College of Biosystems Engineering and Food Science; Zhejiang Key Laboratory for Agro-Food Processing; Fuli Institute of Food Science; Zhejiang R & D Center for Food Technology and Equipment;Zhejiang University, Hangzhou, PR China.
Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, PR China.
PLoS One. 2014 Feb 6;9(2):e87766. doi: 10.1371/journal.pone.0087766. eCollection 2014.
The sonochemical effects of ultrasound (US) treatment on 14 flavonoids representing the main flavonoids in citrus fruit were investigated in a standard mixture by stability evaluation of a model system. Degradation products were further tentatively identified by Fourier transform infrared spectroscopy and high-performance liquid chromatography-ultraviolet detection-electrospray ionization tandem mass spectrometry. Thirteen flavonoids (i.e., eriocitrin, narirutin, neohesperidin, quercitrin, eridictyol, didymin, naringenin, luteolin, sinensetin, nobiletin, tangeretin, naringin, and hesperidin) were fairly stable whereas quercetin was degraded significantly by US treatment. The types of solvent and temperature used were important factors that determined the resulting degradation reactions. The degradation rate of quercetin was highest in 80% ethanol aqueous solution and decreased with increasing temperature. Longer US durations caused increases in the extent of quercetin degradation. Liquid height, ultrasonic intensity, pulse length, and duty cycle of US affected degradation rates but did not change the nature of degradation of the flavonoids. Four types of reactions occurred simultaneously for quercetin under US treatment: oxidation, addition, polymerization, and decomposition. Eight degradation products were tentatively identified as dimer, alcohol addition, oxidation, and decomposition products.
通过模型系统的稳定性评估，研究了超声（US）处理对代表柑橘类水果中主要黄酮类化合物的14种黄酮类化合物的声化学效应。通过傅里叶变换红外光谱和高效液相色谱 - 紫外检测 - 电喷雾电离串联质谱进一步初步鉴定降解产物。13种黄酮类化合物（即橙皮苷、柚皮芸香苷、新橙皮苷、槲皮苷、圣草酚、地奥明、柚皮素、木犀草素、川陈皮素、诺米林、橘红素、柚皮苷和橙皮苷）相当稳定，而槲皮素经超声处理后显著降解。所用溶剂类型和温度是决定最终降解反应的重要因素。槲皮素在80%乙醇水溶液中的降解率最高，且随温度升高而降低。超声处理时间延长会导致槲皮素降解程度增加。液体高度、超声强度、脉冲长度和超声占空比影响降解速率，但不改变黄酮类化合物的降解性质。超声处理下槲皮素同时发生四种反应：氧化、加成、聚合和分解。初步鉴定出8种降解产物为二聚体、醇加成、氧化和分解产物。
