Brewers who create hop-forward styles such as American-style India Pale Ales typically add hops toward the end of or after wort boiling to avoid aroma volatilization and thereby impart strong hopderived aromas.However...Brewers who create hop-forward styles such as American-style India Pale Ales typically add hops toward the end of or after wort boiling to avoid aroma volatilization and thereby impart strong hopderived aromas.However,previous studies have demonstrated that despite the volatilization effects of boiling wort,hops that are added early in the kettle boil can contribute to hop aroma.Nonvolatile hopderived precursors,specifically glycosides,may survive the boiling process and become hydrolyzed to release volatile aglycones capable of contributing to aroma.To investigate the contribution of these different hop fractions to the aroma of kettle-hopped beers,12 single-hopped pilot-scale(3 hL)beers were brewed using pellet,supercritical CO2 extract,and spent hop fractions of Citra,Simcoe,Centennial,or Cascade cultivars.Pellet,extract,and spent additions consisted of a single hop add让ion 5 min into a 60 min boil.Volatile analysis of beers was perfonned using stir-bar sorptive extraction and quantified using gas chromatographymass spectrometry.Beers were analyzed for the common terpenoid compoundsα-pinene,β-pinene,3-myrcene,limonene,linalool,E,β-caryophyllene,α-humulene,andα-terpineol.In addition,beers were evaluated using descriptive sensory analysis.The descriptive sensory data identified significant differences among the cultivar and hop product treatments.The spent hop treatments produced beers that had a noticeable hop aroma,which suggests that the water-soluble components left behind in the spent hops may contribute to hop aroma in beer.The intensity and nature of the hop aroma in the spent treatments were hop variety specific.However,the contributions of water-soluble components found in spent hops to increased aroma intensity in beer were small,especially compared with the pellet and extract treatments.展开更多
采用固相微萃取(solid phase microextraction,SPME)、吹扫捕集-热脱附(purge&trap-thermal desorption,P&T-TD)、搅拌磁子吸附(stir bar sorptive extraction,SBSE)、动态顶空吸附(head space sorptive extraction,HSSE-1、HSS...采用固相微萃取(solid phase microextraction,SPME)、吹扫捕集-热脱附(purge&trap-thermal desorption,P&T-TD)、搅拌磁子吸附(stir bar sorptive extraction,SBSE)、动态顶空吸附(head space sorptive extraction,HSSE-1、HSSE-2和HSSE-3)4种捕集方式联用气相色谱-质谱仪对杭州龙井茶、黄山毛峰茶、山东崂山茶和福建乌龙茶进行分析,研究茶的挥发性香气组分。结果显示:茶的香气主要由烯类、醛类、醇类、酮类、酯类、酸类、芳香族化合物、含氮化合物、杂环化合物、含硫化合物、酚类化合物组成;4类茶均含有大量的烯类、醛类、醇类和酮类化合物,其中福建乌龙茶含量最高;杭州龙井茶、黄山毛峰茶和山东崂山茶属绿茶类,酯类、杂环类、芳香族类以及酚类化合物含量相对较高;通过HSSE-1、HSSE-2对茶叶香气成分进行对比,冲泡前后组分种类和含量略有不同。组分之间的差异使茶形成不同产地不同种类的茶叶的特有风味。展开更多
文摘Brewers who create hop-forward styles such as American-style India Pale Ales typically add hops toward the end of or after wort boiling to avoid aroma volatilization and thereby impart strong hopderived aromas.However,previous studies have demonstrated that despite the volatilization effects of boiling wort,hops that are added early in the kettle boil can contribute to hop aroma.Nonvolatile hopderived precursors,specifically glycosides,may survive the boiling process and become hydrolyzed to release volatile aglycones capable of contributing to aroma.To investigate the contribution of these different hop fractions to the aroma of kettle-hopped beers,12 single-hopped pilot-scale(3 hL)beers were brewed using pellet,supercritical CO2 extract,and spent hop fractions of Citra,Simcoe,Centennial,or Cascade cultivars.Pellet,extract,and spent additions consisted of a single hop add让ion 5 min into a 60 min boil.Volatile analysis of beers was perfonned using stir-bar sorptive extraction and quantified using gas chromatographymass spectrometry.Beers were analyzed for the common terpenoid compoundsα-pinene,β-pinene,3-myrcene,limonene,linalool,E,β-caryophyllene,α-humulene,andα-terpineol.In addition,beers were evaluated using descriptive sensory analysis.The descriptive sensory data identified significant differences among the cultivar and hop product treatments.The spent hop treatments produced beers that had a noticeable hop aroma,which suggests that the water-soluble components left behind in the spent hops may contribute to hop aroma in beer.The intensity and nature of the hop aroma in the spent treatments were hop variety specific.However,the contributions of water-soluble components found in spent hops to increased aroma intensity in beer were small,especially compared with the pellet and extract treatments.
文摘采用固相微萃取(solid phase microextraction,SPME)、吹扫捕集-热脱附(purge&trap-thermal desorption,P&T-TD)、搅拌磁子吸附(stir bar sorptive extraction,SBSE)、动态顶空吸附(head space sorptive extraction,HSSE-1、HSSE-2和HSSE-3)4种捕集方式联用气相色谱-质谱仪对杭州龙井茶、黄山毛峰茶、山东崂山茶和福建乌龙茶进行分析,研究茶的挥发性香气组分。结果显示:茶的香气主要由烯类、醛类、醇类、酮类、酯类、酸类、芳香族化合物、含氮化合物、杂环化合物、含硫化合物、酚类化合物组成;4类茶均含有大量的烯类、醛类、醇类和酮类化合物,其中福建乌龙茶含量最高;杭州龙井茶、黄山毛峰茶和山东崂山茶属绿茶类,酯类、杂环类、芳香族类以及酚类化合物含量相对较高;通过HSSE-1、HSSE-2对茶叶香气成分进行对比,冲泡前后组分种类和含量略有不同。组分之间的差异使茶形成不同产地不同种类的茶叶的特有风味。
