远红外辐射对萎凋叶氧化酶活性及红茶品质的影响

基于远红外特有的光热效应以及光萎凋在茶叶加工中的优越性,通过单因素试验深入分析不同时长和强度的远红外光萎凋对多酚氧化酶(PPO)活性、过氧化物酶(POD)活性及红茶生化成分和感官品质的影响。结果表明,萎凋叶中多酚氧化酶(PPO)活性随远红外光强度的上升而上升,随远红外光时间的延长呈现先上升后下降的趋势,POD活性变化趋势与PPO相似,两者活性均以15 W/m ²远红外光处理3 h的萎凋叶最高且较对照分别提升14.4%和23.5%;此条件处理后的红茶与对照相比氨基酸含量提高8.4%,茶多酚总量下降14.3%,茶黄素含量提高20.5%,茶红素含量提高11.9%,同时感官审评得分最高。实验优化了红茶加工中远红外辐射萎凋的工艺参数,可为远红外辐射在红茶加工中的应用提供理论依据。

Effect of Far-infrared Light Withering on Enzyme Activities of Oxidases and Biochemical Quality of Black Tea

The effects of far-infrared light withering of different duration and intensities on polyphenol oxidase (PPO) activity, peroxidase (POD) activity,biochemical composition, and sensory quality of black tea were analyzed by single factor test based on the special photothermal effect of far-infrared and the advantages of light whitering in tea processing. The results showed that the PPO activity increased with the rise of the far-infrared light intensity, presented a downward trend after rising first with the extension of far-infrared light time; the change of POD activity was consistent with the change of PPO activity, and compared with the control group, the activity of PPO and POD in withering leaves of 15 W/m ² far-infrared light treatment for 3 h increased by 14.4% and 23.5% respectively, the amino acid content of black tea increased by 8.4%, the total amount of tea polyphenols decreased by 14.3%, the content of theaflavin increased by 20.5%, the content of thearubigins increased by 11.9%, and the sensory evaluation score was the highest. The experiment optimizes the process parameters of far-infrared radiation withering and provides a theoretical basis for the application of far-infrared radiation in black tea processing.