Tannins effect

Makkar HPS, Becker K (1993) Vamllin-HQ method for condensed tannins effect of organic solvents used for extraction of tannins. J Chem Ecol 19 613-621... 

Naczk, M., Oickle, D., Pink, D., Shahidi, F. (1996). Protein precipitating capacity of crude canola tannins Effect of pH, tannin, and protein concentrations. J. Agric. Food Chem., 44, 2144-2148. 

ABSTRACT Radiata pine bark contains a large amount of polyflavanoids (radiata tannin) and other valuable materials suitable for feedstock of adhesives and resins. We tried to extract radiata tannin effectively and to partially degrade the bark to water soluble materials using hot compressed water. 

CTs can be effective anti-nutrients against insects, especially at high concentrations as can be found in P. tremuloides (up to 18 % DW). ° Tannin effectiveness and mechanism of action has been debated, but it clearly depends both on variations in chemical structure and plant source, as well as on the biochemical conditions in the gut of the particular insect species. In P. tremuloides, CT levels were shown to be negatively correlated with gypsy moth and forest tent caterpillar larvae performance, although the effects were smaller than with the phenolic glycosides (C. P. Constabel and J. Spence, unpublished data). ... 

Tannins represent a class of plant secondary metabolites and are produced by plants in their intermediary metabolism. Tannins are considered to be a promising group of substances to decrease methane (CH ) emission from ruminants by dietary means. However, there is no common agreement whether tannins generally decrease CH formation in vivo or not and to which extent (Beauchemin et al., 2008). Therefore, research on this particular topic is needed to summarize and to quantify the tannin effects on CH production from ruminants and its associated variables. The objective of this study was to estimate the relationship between dietary tannin levels and CH emission from ruminant animals by compiling available literature data of respective experiments using a statistical meta-analysis approach. 

Plants and microorganisms produce unique and diverse chemical stmctures, some of which act as immunomodulators (18—28). Of specimens used in traditional medicine, approximately 450 plant species have shown antiviral activity out of 4000 plants screened (19). Several tannins (20) exhibit strong inhibition of tumor promotion experimentally. Pretreatment of mice with small amounts of tannins for several days strongly rejected transplanted tumors. This activity has been claimed to be effected through enhancement of host-mediated antitumor activity. 

The apphcation of vegetable tanning materials has an additive effect on the leather. The more vegetable tannins appHed the more the leather becomes like vegetable-tanned leather. The color is changed, the fullness of feel increases, and the leather can be worked and embossed like vegetable leather. 

The mechanism of the tarmage is accepted to be largely one of replacement of the bound water molecules by the phenoHc groups of the tannin and subsequent formation of hydrogen bonds with the peptide bonds of the protein. The effect of this bonding is to make the leather almost completely biorefractive. 

Tannins occur in many plants and are separated by extraction. At present, only quebracho extract is used as a mud thinner in significant quantity in the United States. Quebracho is an acidic material and performs best at high pH. It is an excellent thinner for lime-treated and cement-contaminated muds. However, it is not effective at high salt concentrations. Sulfomethylated tannin products are functional over a wide range of pH and salinity and have either been treated with chromium for good thermal stabiUty (58) or are chrome free. Concentrations of tannin additives are ca 1.5—18 kg/m (0.5—6 lb/bbl). 

Maturing improves the taste and aroma of beer and the elimination of tannin, protein, and hop resins also has a beneficial effect. Some metaboHc products of unpleasant taste are further converted or washed out by the carbon dioxide surplus. The time for 1 agering varies with different types of beer. For every type of beer there is an optimal 1 agering time, and longer ] agering is usually detrimental to beer quaHty. The fiHed 1 agering tanks are subjected to the saturating pressure of carbon dioxide, usually 50—70 kPa (ca 0.5—0.7 atm), controUed by a safety valve. 

A study of the effect on the congener levels of up to eight refills of a used whiskey barrel iadicate that volatile acids, esters, colors, soHds, and tannins showed the greatest percentage change between the first and second use of a new charred barrel (11). 

Locomotive diesels As larger volumes of coolant are required in railway locomotives than in road vehicles, the cost of inhibition is proportionally greater. An additional factor is the possibility of cavitation attack of cylinder liners. These considerations place a restriction on the choice of inhibitors. In the past, chromates have been used at concentrations of up to 0-4%, but their use presents handling and disposal problems. Chromates cannot be used with ethanediol antifreeze solutions. A IS I borate-metasilicate at a concentration of 1 % has been used in the UK. Nitrate is added to this to improve inhibition of aluminium alloy corrosion. Tannins and soluble oils are also used, but probably to a lesser extent than in the past. The benzoate-nitrite formulation (formerly BS 3151) is effective and has been used by continental railways . ... 

Here, the use of inhibitor formulations having a less dramatic effect on TDS (such as certain tannins) may be extremely beneficial. Formulations are available that are based on tannin chemistry and contain blends that act as oxygen scavengers and metal passivators, with additional sludge dispersant and antifoam properties. 

Effective metal waterside surface passivation (using hydrazine, DEHA, tannin, or similar products) remains an essential requirement of higher temperature or pressure system programs. 

Tannins, as DCAs, are particularly effective in conditioning carbonate-cycle sludges. 

For HW, LP steam, and many lower pressure industrial operations, sulfite or sulfite derivatives have proved to be excellent scavengers and suitably cost-effective, provided the MU requirements are not too high and FW temperatures not too low. Alternatively, tannin-based products provide a similar degree of effectiveness without the contribution to TDS and, in practice, almost irrespective of FW oxygen content. 

UCHIDA S, OZAKI M, KASHI T, YAMASHITA K, NIWA M and TANIYAMA K (1995) Effects of (-)-epigallocatechin-3-O-gallate (green tea tannin) on the life span of stroke-prone spontaneously hypertensive rats , Clin Exp Pharmacol, 11 (Suppl 1), S302-303. 

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