[Objectives] This study was conducted to analyze the differences in procyanidine content in grapes caused by different producing areas. [Methods]With Muscat Hamburg grape from different producing areas as an experimen...[Objectives] This study was conducted to analyze the differences in procyanidine content in grapes caused by different producing areas. [Methods]With Muscat Hamburg grape from different producing areas as an experimental material,procyanidine content was determined by n-butanol-hydrochloric acid colorimetry. [Results] The procyanidins contents in different parts of the same variety ranked as grape seed > grape skin > grape flesh. The procyanidins contents in grapes from different producing areas were in order of Changli County,Hebei Province > Dazeshan Town,Shandong Province > Hangu District,Tianjin City.[Conclusions]The procyanidins contents in Muscat Hamburg grapes from different producing areas differ to a certain degree.展开更多
To study the effects of different soil conditions on winter nutrient storage of Muscat Hamburg branches,this study compared the soil texture,bulk density,total salt content and soil K,Ca,Na,Mg and total Fe contents of...To study the effects of different soil conditions on winter nutrient storage of Muscat Hamburg branches,this study compared the soil texture,bulk density,total salt content and soil K,Ca,Na,Mg and total Fe contents of Muscat Hamburg vineyards in Ninghe District and Hangu District,Binhai New Area of Tianjin and analyzed the soluble sugar and soluble protein contents in one-year-old vine branches. The results showed that the soil p H was lower,and the soil K,Ca and total salt( 0. 445%) contents were higher in the vineyard of Ninghe District than those in the vineyard of Hangu District. There were no significant differences in the soil Mg,Fe and Na contents between the vineyards in the two regions. The soil of the vineyard in Ninghe District is medium loam,and that in Hangu District is heavy loam. In short,all the soil indicators of the vineyard in Ninghe District were better than those in Hangu District except the indicator of soil salt content. The soluble sugar and soluble protein contents of one-year-old vine branches differed significantly between the two regions.展开更多
ß-Glucosidases(ßGL)-widely used in the enological field-are enzymes that catalyze the liberation of aromatic volatiles from their glycosidic precursors during winemaking.In the present study,aßGL obtain...ß-Glucosidases(ßGL)-widely used in the enological field-are enzymes that catalyze the liberation of aromatic volatiles from their glycosidic precursors during winemaking.In the present study,aßGL obtained from the Antarctic yeast Mrakia sp.LP 7.1.2016 was produced on a bioreactor scale,purified,characterized,and the enzyme’s properties studied for a potential enological application.Sodium-dodecylsulfate-polyacrylamide-gel electrophoresis indicated a high molecular weight for this enzyme,it having at least two subunits of 134 and 14 kDa.ßGL exhibited a pH optimum of 5.0 and retained substantial activity and stability at pH 4.0.The temperature range for optimal activity was 50-55℃,with the enzyme demonstrating thermostability up to 50℃ and retaining 87%of residual activity at that temperature after 3 h.The respective kinetic constants determined with p-nitrophenyl-ß-D-glucopyranoside and cellobiose were 0.38 and 1.79 mM for Km and 20.1 and 5.65μmol^(-1)mg^(-1)min^(.1) for Vmax,ß-Glucosidase manifested high activity in 10-25%(v/v)ethanol,30.0 mg L^(-1)sulfur dioxide,and 10-200 g L^(-1)fructose;but it was strongly inhibited by glucose,retaining only 6%of residual activity in the presence of 20 g L^(-1).Upon investigating the influence of the enzyme on Muscat-wine glycosidic precursors,we found significant differences in terpene content after 14 days ofßGL treatment at an eightfold increase over control-wine levels.The enzyme was more active toward the precursors of the monoterpenes nerol and geraniol and oxides of trans-and cis-linalool.These findings contribute to our understanding of the potential of cold-active enzymes in advantageous biotechnological applications to enology.展开更多
基金Supported by the Key Research and Development Foundation of Tianjin City(17YFXTZC00040)Agriculture Product Quality and Security Detection Foundation of Ministery of Agriculture(181821301092362005)Tianjin Science and Technology Program(17JCYBJC29800,16PTZSTG00020)
文摘[Objectives] This study was conducted to analyze the differences in procyanidine content in grapes caused by different producing areas. [Methods]With Muscat Hamburg grape from different producing areas as an experimental material,procyanidine content was determined by n-butanol-hydrochloric acid colorimetry. [Results] The procyanidins contents in different parts of the same variety ranked as grape seed > grape skin > grape flesh. The procyanidins contents in grapes from different producing areas were in order of Changli County,Hebei Province > Dazeshan Town,Shandong Province > Hangu District,Tianjin City.[Conclusions]The procyanidins contents in Muscat Hamburg grapes from different producing areas differ to a certain degree.
基金Supported by Major Agricultural Technology Extension Project of Tianjin City(2017CK0184)Tianjin Agricultural and Rural Affairs Committee(ITTHRS2018002)Special Commissioner Project of Tianjin Science and Technology Commission(17ZXBFNC0031)
文摘To study the effects of different soil conditions on winter nutrient storage of Muscat Hamburg branches,this study compared the soil texture,bulk density,total salt content and soil K,Ca,Na,Mg and total Fe contents of Muscat Hamburg vineyards in Ninghe District and Hangu District,Binhai New Area of Tianjin and analyzed the soluble sugar and soluble protein contents in one-year-old vine branches. The results showed that the soil p H was lower,and the soil K,Ca and total salt( 0. 445%) contents were higher in the vineyard of Ninghe District than those in the vineyard of Hangu District. There were no significant differences in the soil Mg,Fe and Na contents between the vineyards in the two regions. The soil of the vineyard in Ninghe District is medium loam,and that in Hangu District is heavy loam. In short,all the soil indicators of the vineyard in Ninghe District were better than those in Hangu District except the indicator of soil salt content. The soluble sugar and soluble protein contents of one-year-old vine branches differed significantly between the two regions.
基金supported by grants from the National Scientific and Technological Research Council and the National Agency for the Promotion of Science and Technology under Grants number PICT 2018-3194 and PICT 2019-3123.
文摘ß-Glucosidases(ßGL)-widely used in the enological field-are enzymes that catalyze the liberation of aromatic volatiles from their glycosidic precursors during winemaking.In the present study,aßGL obtained from the Antarctic yeast Mrakia sp.LP 7.1.2016 was produced on a bioreactor scale,purified,characterized,and the enzyme’s properties studied for a potential enological application.Sodium-dodecylsulfate-polyacrylamide-gel electrophoresis indicated a high molecular weight for this enzyme,it having at least two subunits of 134 and 14 kDa.ßGL exhibited a pH optimum of 5.0 and retained substantial activity and stability at pH 4.0.The temperature range for optimal activity was 50-55℃,with the enzyme demonstrating thermostability up to 50℃ and retaining 87%of residual activity at that temperature after 3 h.The respective kinetic constants determined with p-nitrophenyl-ß-D-glucopyranoside and cellobiose were 0.38 and 1.79 mM for Km and 20.1 and 5.65μmol^(-1)mg^(-1)min^(.1) for Vmax,ß-Glucosidase manifested high activity in 10-25%(v/v)ethanol,30.0 mg L^(-1)sulfur dioxide,and 10-200 g L^(-1)fructose;but it was strongly inhibited by glucose,retaining only 6%of residual activity in the presence of 20 g L^(-1).Upon investigating the influence of the enzyme on Muscat-wine glycosidic precursors,we found significant differences in terpene content after 14 days ofßGL treatment at an eightfold increase over control-wine levels.The enzyme was more active toward the precursors of the monoterpenes nerol and geraniol and oxides of trans-and cis-linalool.These findings contribute to our understanding of the potential of cold-active enzymes in advantageous biotechnological applications to enology.
