Total soluble nitrogen

Literature on the cause and control of the flavor of crackers is scant. Faridi and Johnson (10) studied the chemical changes related to flavor precursor components (organic and amino acids) during the twenty-five hour fermentation period. They measured the total soluble nitrogen, peptides, primary amines, and ammonia formed in cracker doughs as a result of the lengthy fermentation. All components increased... 

ISO 14255 1998 Soil quality - Determination of nitrate nitrogen, ammonium nitrogen and total soluble nitrogen in air-dry soils using calcium chloride solution as extractant. 

FIGURE 4.3. Distribution of soluble and gaseous nitrogen species. Total soluble nitrogen is assumed to be 10-3 M. (Adapted from Lindsay (1979).)... 

However, it was not possible to construct a reasonable calibration equation for either total soluble nitrogen or bitterness with either transmission or transflectance NIR. With transmission NIR, the best SEC obtained for total soluble nitrogen was 140 mg-l and the correlation coefficient was 0.94, and for bitterness was 8 B.U. and correlation coefficient was 0.72, which were far too great to be of practical use. These constituents are found in beer in only ppm concentrations, and NIR methods may be not capable of reliable measurement at these levels. 

Despite the fact that crude APPL s are totally soluble in DMF, an important residue is obtained at the end of the solvent sequence (0 100, THF DMF) indicating that the protein-rich fractions require association with the polyphenolic part for their solubilization in DMF (Table VI). Because each APPL has a different amino acid composition, its solubility distribution is also different, but in both cases, the THF fraction is the most lignin-like, with only 1% nitrogen. This is confirmed by FTIR analysis (Fig. 7). As the fractionation proceeds with increasing solvent polarity, the lignin characteristic bands at 1515, 1460, 1265, 1095, 1035, and 810 cm-1 disappear, while the amide characteristic bands at 3290 and 3080 cm-1 appear. 

The more modem approach to the problem of mixing nitrocellulose consists of mixing defined types of nitrocellulose in the nitrocellulose factory itself. In this case the two forms of nitrocellulose are mixed under water in mixers as described in Vol. II, p. 374. The water is then centrifuged and the mixture dehydrated with alcohol. This method, however, creates certain inconvenience to the powder factory which loses the possibility of changing (within certain limits) the composition of the mixtures, i.e. nitrogen content and total solubility of nitrocellulose. The powder factory is therefore compelled to limit the number of factors which can be varied to obtain the powder of required ballistic properties. 

The batching of nitrocellulose consists of weighing the guncotton and collodion cotton in a ratio which gives a mixture of suitable nitrogen content with the required total solubility. 

The quantity of waste products added to the fresh dough in the kneaders varies depending on the amount of factory waste arising during manufacture. From 20 to 90 kg of waste products may be added per 100 kg of fresh nitrocellulose...Naturally the waste products added to fresh powder should have a suitable nitrogen content and total solubility. 

Shorygin and Khait [57] first drew attention to the fact that cellulose brought into contact with nitrogen dioxide is converted into a substance totally soluble in alkali solution. This reaction was then investigated in more detail by Kenyon et al. [58] as well as by Rogovin et al. [59]. 

FIGURE 5.17 Residual levels of (a) ttg,-casein and (b) P-casein, expressed as a percentage of the amount in the corresponding 1-day-old cheese (c) levels of water-soluble nitrogen (WSN) and (d) total free amino acids (TFAA) in control ( ) 3P1 ( ) and 3P15 (a) ewe milk cheese throughout ripening. (From Juan, B. et al., Int. Dairy J., 18, 129, 2008. With permission.)... 

St Total solubility of the neutral and ionized forms of a substance (M) C-moles of biomass produced per C-mole of substrate consumed )p/s C-moles of product per C-mole of substrate consumed Tn/s Moles of nitrogen source consumed per C-mole of substrate consumed Tbj/s Moles of O2 consumed per C-mole of substrate consumed Fw/s Moles of water consumed per C-mole of substrate consumed Fc/s Moles of CO2 produced per C-mole of substrate consumed Fq/s Heat flow per C-mole of substrate consumed Z Charge on a protein 9 Extent of coverage in ligand binding CO Rotational speed in an ultracentrifuge (1/s)... 

Nitrogen soluble in 12% TCA is referred to as non-protein nitrogen (NPN), of which milk contains 250-300mgl i.e. 5-6% of total milk nitrogen. The NPN is a very heterogeneous fraction (Table 4.7). 

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