The Analysis Of The Components Of Xinglong Coffee With Different Degree Of Roasting And The Effect Of Roasting Process On Quality

Hainan Xinglong as the main medium grain coffee planting area,this article used Hainan Xinglong coffee as raw material.To study the composition of aroma components,composition of active ingredients and their changing rules in different degrees of roast coffee.Headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry(HSSPME/GC-MS)and electronic nose for the analysis of volatile components in coffee beans with different degrees of roasting;At the same time,Analyzed the composition and change of its flavoring substances;On the basis,using SCA to optimize the roasting process of medium coffee and study its effect on coffee quality;Meanwhile,Analysis of changes in antioxidant activity and enzyme inhibition during roasting,to lay the foundation for the roasting process and quality improvement of Xinglong Coffee.The main findings were as follows:(1)A total of 91 compounds were identified in roasted samples.In the JQ,Q and QZ samples,they were mainly composed of acids and pyrazines showing that nuts and sourin flavor.The Z and ZS samples were mainly comprised of furans,pyrroles and ketones,which appeared as caramel and burning flavor,and the S,JS and FZ samples were mainly composed of phenols and pyridines contributing to the smoked and delightful flavor.(2)With the increase of roasting degree,protein and fat content increased gradually,which content were the most in the FZ sample.A total of 7 organic acids were identified in roasted samples,with the increase of roasting degree,organic acid content increased firstly and then decreased.A total of 4 chlorogenic acids,the 5-O-CQA content was the most,and in the FZ sample.There are 17 kinds of amino acids were detected,and 7 kinds of essential amino acids,2 kinds of semi-essential amino acids and 8 kinds of non-essential amino acids.The content of total amino acids decreased with the increase of roasting degree.With the increase of roasting degree,absorbance of browning index increases.(3)When medium coffee beans are roasted,the roasting temperature,roasting power and roasting time increase,the overall score of SCA first increased and then decreased.The temperature was 195?,the fire was 6.5,the time was 8 minute when the coffee beans roasting,the human's sensory evaluation score was the maximum,which was optimal roasting.The quality parameters(pH,TS,TA,TSS)and browning index(BI)were determined under the optimum conditions of medium coffee roasted,which were 5.48±0.0,1.32±0.1,2.33,0.1,2.05±0.0,respectively.0.60±0.0.(4)Finally,the secondary effect of roasting fire power was observed in the determination of total phenolics,antioxidant capacity and enzyme inhibitory activity.By RSM analysis,when the roasting temperature was 185°C,the roasting fire power was 6.5,and the roasting time was 9 min,the optimum roasting conditions were obtained.Roasting fire power was an important parameter for total phenolics,antioxidant capacity and enzymes inhibitory activity in coffee roasting.By increasing or decreasing roasting firepower,the same amount of coffee beans could provide consumers with higher antioxidant capacity and enzyme inhibitory activity.