摘要
为探究水质因子对冷萃咖啡主要成分及感官风味的影响,本研究选择 6种不同的市售水通过冷萃的方式制备咖啡萃取液,采用高效液相色谱(HPLC)技术和顶空固相微萃取-气质联用(HS-SPME-GC-MS)技术鉴定 6组冷萃咖啡液,比较分析 6组冷萃咖啡理化指标、非挥发性成分、挥发性成分、感官评价的差异,并进行相关性和主成分分析(PCA).结果显示,不同类型的水样主要离子含量差异较大,水中离子对冷萃咖啡的萃取浓度、萃取率、pH、可滴定酸、咖啡因、葫芦巴碱和呋喃类挥发性化合物整体有较大影响,对总酚、绿原酸、咖啡酸、抗氧化活性影响较小.水中的Ca2+、Mg2+、HCO3-与冷萃咖啡的萃取浓度、萃取率、咖啡因、葫芦巴碱呈显著正相关(P<0.05),与可滴定酸值呈显著负相关(P<0.05).糠醇、5-甲基糠醛、1-糠基吡咯、糠基甲基硫醚、2-异丁基-3-甲氧基吡嗪、乙酸糠醇酯这些挥发性化合物与水中总离子含量有较大关联.PCA图分析显示,水中较低的离子含量能促进咖啡花果风味的体现,随着水中Ca2+、Mg2+、HCO3-的增加,咖啡的花果味、酸味、甜味会有不同程度的减弱.较高的离子含量(尤其是Na+、K+)能促进咖啡焦糖味、苦涩味的体现,Na+、K+对糠醇含量影响较大,Ca2+、Mg2+、HCO3-对 1-糠基吡咯、5-甲基糠醛、糠基甲基硫醚含量影响较大,而用中等的离子含量的水冲泡的冷萃咖啡有较好的坚果味、烘焙味、甜味、风味和总体感官评价.研究结果可为深入认识水质因子对咖啡理化特性与主要成分的影响提供一定理论依据.
Abstract
In this study,six types of commercially available water were selected for preparing cold brew coffee to explore the influence of water quality factors on the main components and sensory flavor of the coffee.High-performance liquid chromatography(HPLC)and headspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME-GC-MS)were used for analysis of the coffee.Physical and chemical indices,volatile and non-volatile components,and sensory evaluation were analyzed and compared,and correlations and principal component analysis(PCA)were performed.It was found that the different types of water had significantly different compositions of major ions.The contents of total phenol,chlorogenic acid,and caffeic acid,as well as antioxidant activity in the cold brew coffee were not significantly affected by the water ions,but they were significantly affected by the extraction concentration,extraction rate,pH,and titratable acid,caffeine,trigonelline,and furan volatile chemical components.The Ca2+,Mg2+,and HCO3-ions in the water were positively correlated with the extraction concentration,extraction rate,and caffeine and trigonelline concentrations in the cold brew coffee(P<0.05),and negatively correlated with titratable acid(P<0.05).The ions in the water had significant effects on volatile compounds such as furfuryl alcohol,5-methylfurfural,1-furfurylpyrrole,furfuryl methyl sulfide,2-isobutyl-3-methoxy-pyrazine,and furfuryl acetate.PCA showed that lower ion concentrations in the water promoted fruit and flower flavors in the coffee,and higher concentrations of Ca2+,Mg2+,and HCO3-reduced the fruit and flower flavor,as well as sweet and sour taste in different degrees.Higher ion contents(especially Na+ and K+)enhanced caramel flavors and bitterness in the coffee.Na+ and K+ significantly affected the furfuryl alcohol content,while Ca2+,Mg2+,and HCO3-influenced 1-furfuryl pyrrole,5-methylfurfural,and furfuryl methyl sulfide.Cold brew coffee brewed in water with moderate ion contents showed better nutty,roasted,and sweet flavors,as well as better overall sensory evaluation.These results could provide a theoretical basis for further understanding the effects of water quality factors on the physicochemical properties and main components of coffee.
基金项目
上海科技成果转化促进会联盟计划(LM201956)
维普
万方数据