scholarly journals Free Amino Nitrogen in Brewing

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 22 ◽  
Author(s):  
Annie Hill ◽  
Graham Stewart

The role of nitrogenous components in malt and wort during the production of beer has long been recognized. The concentration and range of wort amino acids impact on ethanolic fermentation by yeast and on the production of a range of flavour and aroma compounds in the final beer. This review summarizes research on Free Amino Nitrogen (FAN) within brewing, including various methods of analysis.

2019 ◽  
Vol 279 ◽  
pp. 356-363 ◽  
Author(s):  
Yu Matsuo ◽  
Larissa Akari Miura ◽  
Tetsuya Araki ◽  
Yumiko Yoshie-Stark

1970 ◽  
Vol 21 (5) ◽  
pp. 723 ◽  
Author(s):  
J Leibholz

Crossbred wethers were given a control diet (8 g nitrogen, 730 g dry matter daily) or a low nitrogen diet (0.5 g nitrogen, 520 g dry matter daily) or starved, for a 12 or 20 day experimental period. The concentrations of free serine, glutamine, glycine, alanine, histidine, and arginine in the plasma of the starved sheep decreased significantly while the concentrations of lysine, 3-methylhistidine, and isoleucine increased significantly. The ratio of essential to non-essential amino acids increased from 0.35 to 0.56 in the starved sheep. In sheep on the low nitrogen diet, the ratio of essential to non-essential amino acids in the plasma decreased from 0.40 to 0.27, with significant increases in the concentrations of glutanlic acid, glutamine, glycine, isoleucine, leucine, and 3-methylhistidine. Starvation and the low nitrogen diet both resulted in a reduction of the plasma urea concentrations. Starvation and the low nitrogen diet resulted in a 20-50 % reduction in the flow of saliva and a 40-78% increase in the concentration of total nitrogen. This resulted in no significant change in the daily secretion of nitrogen in the saliva. The concentration of urea in the saliva was increased by 3-54%. The concentrations of individual free amino acids in saliva are reported. The nitrogen content of the rumen was reduced, and after 7 days of starvation or on the low nitrogen diet all rumen nitrogen could be attributed to ammonia and free �-amino nitrogen.


Author(s):  
D. J. Read ◽  
R. Bajwa

SynopsisSome aspects of the role of the ericoid mycorrhizal symbiosis in the ecology and physiology of ericaceous plants are described. Mycorrhizal infection leads to enhancement of plant nitrogen content and an experimental analysis of the basis of this effect is reported. In addition to improving the efficiency of ammonium absorption at low concentrations, the mycorrhizal endophyte utilises amino acids, peptides and proteins as nitrogen substrates for growth. These are the predominant nitrogen sources in organic heathland soil. It is suggested that the success of ericaceous plants in such soils may arise through the capacity of the mycorrhizal fungus to provide its host with access to this nutrient resource. A model is described in which absorption of ammonium and amino nitrogen leads to soil acidification, increased acid protease activity and improved vigour of the ericaceous plants.


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