Acid, acetic propionic

At identification of cognacs and cognac alcohols on authenticity use the following characteristic attributes presence in them significant concentration of (15-150 mg/1) bytanol, the high level of acids - acetic, propionic and oil the high contents of polyphenolic bonds. 

The nature of the diet sets the basic pattern of metabohsm. There is a need to process the products of digestion of dietary carbohydrate, lipid, and protein. These are mainly glucose, fatty acids and glycerol, and amino acids, respectively. In ruminants (and to a lesser extent in other herbivores), dietary cellulose is fermented by symbiotic microorganisms to short-chain fatty acids (acetic, propionic, butyric), and metabohsm in these animals is adapted to use these fatty acids as major substrates. All the products of digestion are metabohzed to a common product, acetyl-CoA, which is then oxidized by the citric acid cycle (Figure 15-1). 

The title compounds la-e were obtained in fair to good yields through the cyclization of 2 with a variety of one carbon donors such as formic acid, acid acetic, propionic acid, buturic acid, and chloroacetyl chloride at reflux (Scheme 1). 

Due to fermentation of hitherto undigested carbohydrates by the cecal and colonic bacteria (the large bowel contains concentrations of bacteria of up to 10lo-1012 bacteria/ mL), the pH in the proximal colon is usually lower than that of the ileum. This is reflected in the composition of SCoF, which is essentially an acetate buffer. The use of acetate is appropriate as it is known that the products of carbohydrate fermentation include very short chain acids (acetate, propionate, and butyrate are typical). 

Films of various stoichiometries of Sn-S have been deposited from carboxylic acid (acetic, propionic, butyric) solutions of elemental S and SnCli. Depending on deposition conditions, in particular whether some water was present and how much, as well as the presence of complexing agents, films of approximate composition SnS, SniSs, or SnS2 could be formed. Interestingly, various Sn-S films were also formed on the walls of the deposition vessel above the liquid level (by several centimeters) this was attributed to reaction between volatile SnCU and H2S, both formed in the deposition bath. 

The reaction products were analyzed by chromatography and chromatomass-spectrometry. The complex mixture of oxygen containing organic compounds and C - C6 hydrocarbons was formed. Oxygen containing products consist of C - C4 aldehydes (formaldehyde, propionic aldehyde, butiraldehyde), C2 - C4 acids (acetic, propionic, butyric), acetone, ethanol and the traces of C3 - C4 alcohols of normal structure. 

Similar results are given for mixtures of water and organic acids (acetic, propionic, acrylic) by Kitao and Asaeda [52] for rather thick (10 pm) silica membranes supported by y-Al203 and made in a multi step process (up to 15 layers on top of each other). A permeation mechanism and a model for the pore... 

The large intestine extends from the ileocecal valve to the anus. It is wider than the small intestine except for the descending colon, which when empty may have the same diameter as the small intestine. Major functions of the colon are absorption of water, Na+, and other electrolytes, as well as temporary storage of excreta followed by their elimination. The colon harbors large numbers of mostly anaerobic bacteria that can cause disease if they invade tissues. These bacteria metabolize carbohydrates to lactate, short-chain fatty acids (acetate, propionate, and butyrate), and gases (CO2, CH4, and H2). Ammonia, a toxic waste product, is produced from urea and other nitrogenous compounds. Other toxic substances are also produced in the colon. Ammonia and amines (aromatic or aliphatic) are absorbed and transported to the liver via the portal blood, where the former is converted to urea (Chapter 17) and the latter is detoxified. The liver thus protects the rest of the body from toxic substances produced in the colon. Colonic bacteria can also be a source of certain vitamins (e.g., vitamin K, Chapter 36). 

Carboxylic acids Acetate, propionate, maleate, benzoate, salicylate, fumarate... 

For a number of reasons, a great deal of effort has been directed to the degradation of alkanoic acids acetate, propionate, and butyrate are fermentation products of carbohydrates and are metabolites of the aerobic degradation of alklanes and related compounds, while long-chain acids are produced by the hydrolysis of lipids. Studies on the degradation of alkanoic adds have been carried out using both pure cultures and syntrophic associations that have been discussed in Section 4.5.1. 

Figure 22. Spectrum of outlet 3 without nitrate (see Fig. 21) and spectra of some carboxylic acids (acetic, propionic and butyric acids).

Effect of Anions in Copper Compounds. Since the copper stearate was the most effective catalyst among the transition metal stearates for the early stage of the thermal oxidation of polypropylene, the effect of anions in copper compounds on the thermal oxidation of atactic polypropylene was examined. The oxygen uptake curves of the polymer in the presence of various copper compounds (acetate, propionate, butylate, stearate, laurate, polyacrylate, and cupric oxide) are shown in Figure 4. In the absence of the copper compounds, oxygen uptake of the polymer increases linearly with time. In the presence of copper compounds of fatty acids (acetate, propionate, butyrate, laurate, and stearate), the oxygen uptake of the polymer levels off at ca. 25-30 O2 mL/g polymer after... 

Organic acids [acetate, propionate, butyrate, alcohols, and COJ... 

Wheat bran cellulose is much less well digested than that of fruit and vegetables and this has been attributed to its lignin content. The chief products of the anaerobic fermentation of fibre are volatile fatty acids (acetate, propionate and butyrate), gas (CO2, Ha and methane) and energy. Gas production is a normal part of colonic metabolism but may be one of the reasons why people in the West have tended to maintain a relatively low fibre intake. 

Root contains inulin (up to approx. 45%) polyacetylenes (0.001-0.002%, dry-weight basis) consisting mainly of 1,1 l-tridecadiene-3,5,7,9-tetrayne and 1,3,1 l-tridecatriene-5,7,9-triyne arctic acid and lappaphens a and b (acetylenic acids containing S) volatile acids (acetic, propionic, butyric, isovaleric, 3-hexenoic, 3-octenoic, costic, etc.) and nonhydroxy acids (lauric, myristic, stearic, palmitic, etc.) a... 

Short-chain aliphatic acids (acetic, propionic, and butyric) have been... 

Two main hypotheses have been advanced to explain the faecal bulking properties of fibre. The water-holding idea, mentioned above, is probably the most widely held view. In addition, it was suggested by Williams and Olmsted in 1936 that the way in which fibre increased faecal weight was through an effect of its metabolites, the short-chain fatty acids (acetic, propionic and butyric). They noted that dietary fibre was broken down in the gut and that the increased faecal weight was associated with an increased faecal excretion of short-chain fatty acids. 

Particulate carbohydrates, proteins, fats amino acids, sugars, fatty acids Amino acids and sugars —> propionate, acetate fatty acids —> acetate Propionate — acetate Acetate —> CH4 H2, CO2 CH, Siegrist et al. (2002)... 

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