scholarly journals Characteristics of Free Amino Acids (the Quality Chemical Components of Tea) under Spatial Heterogeneity of Different Nitrogen Forms in Tea (Camellia sinensis) Plants

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 415 ◽  
Author(s):  
Li Ruan ◽  
Kang Wei ◽  
Liyuan Wang ◽  
Hao Cheng ◽  
Liyun Wu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Spatial Heterogeneity ◽  
Root Length ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Performance ◽  
The Other ◽  
Chemical Components ◽  
Split Root System ◽  
Analysis System

Nitrogen (N) forms are closely related to tea quality, however, little is known about the characteristics of quality chemical components in tea under the spatial heterogeneity of different N forms. In this study, a split-root system, high performance liquid chromatography (HPLC), and root analysis system (WinRHIZO) were used to investigate free amino acids (FAAs) and root length of tea plants under the spatial heterogeneity of different N forms. Uniform. (U.) ammonium (NH4+) (both compartments had NH4+), U. nitrate (NO3−) (both compartments had NO3−), Split. (Sp.) NH4+ (one of the compartments had NH4+), and Sp. NO3− (the other compartment had NO3−) were performed. The ranking of total FAAs in leaves were as follows: U. NH4+ > Sp. NH4+/Sp. NO3− > U. NO3−. The FAA characteristics of Sp. NH4+/Sp. NO3− were more similar to those of U. NO3−. The contents of the important FAAs (aspartic acid, glutamic acid, and theanine) that determine the quality of tea, increased significantly in U. NH4+. The total root length in U. NH4+ was higher than that in the other treatments. More serious root browning was found in U. NO3−. In conclusion, NH4+ improved the accumulations of FAAs in tea leaves, which might be attributed to the root development.

THE ESTIMATION OF FREE AMINO ACIDS USING A MICRODIFFUSION TECHNIQUE

1952 ◽  
Vol 30 (7) ◽  
pp. 522-528 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
The Other ◽  
Routine Analysis ◽  
Average Deviation ◽  
Substantial Saving ◽  
Ionic Concentrations ◽  
The Mean

The carbon dioxide evolved when α-amino acids were heated for one hour at 85 °C. with ninhydrin was determined in a partially evacuated microdiffusion cell. Distillation of solvent from one chamber to the other was minimized by keeping the ionic concentrations of the reaction mixture and absorbing mixture approximately equal. The method was useful for samples of amino acids which liberated from 0.06 to 0.3 mgm. of carbon dioxide. The average deviation from the mean was somewhat less than 1% for samples liberating 0.2 mgm. of carbon dioxide. Use of the method for routine analysis of enzymatic digests resulted in substantial saving of time and material.

scholarly journals Green coffee derived supplements and infusions as a source of polyamines and free amino acids

2020 ◽  
Author(s):  
Lukas Macheiner ◽  
Anatol Schmidt ◽  
Helmut K. Mayer
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Performance ◽  
Nutritional Supplements ◽  
Green Coffee ◽  
Edible Portion ◽  
Green Coffee Beans ◽  
Coffee Beans ◽  
Detection And Quantification

Abstract This work reports on monoamines (MA), diamines (DA) and polyamines (PA) as well as free amino acids (fAA) in nutritional supplements and infusions derived from green coffee beans. Samples were investigated using a ultra-high performance liquid chromatography UV/FLR method, which was validated regarding specificity, linearity, range, precision, accuracy and limits of detection and quantification. Nutritional supplements based on green coffee beans showed large amounts of total amines ranging from 1090 to 2593 mg/kg, with exceptional high levels of spermidine up to 724 mg/kg, and a content of fAA from 4004 to 12,389 mg/kg. Infusions brewed from green coffee beans showed much lower contents of amines (14–17 mg/L) and fAA (78–100 mg/L). However, if the customary edible portion was considered, infusions from green coffee were a mainly better source for MA and PA as well for fAA, compared to nutritional supplements. Tryptamine and tyramine were predominant as MA putrescine as DA, and spermidine as PA, respectively. Graphic abstract

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