Glycerol, butyric acid from

D,L-GIyceraldehyde, III, 166 Glyceric acid, effect on conductivity of boric acid, IV, 195 reduction of, IV, 109 D-GIyceric acid, III, 21 D,L-GIyceric acid, III, 132, 167 Glycerides, trityl ethers, III, 105 —, unsaturated, II, 125 Glycerol, butyric acid from, IV, 110 effect on conductivity of boric acid, IV, 191... 

More than seventy years ago the impressive discovery was made that bioreduction of mannitol, glycerol and starch yields butanol. Fermentations in which butyric acid, butanol and acetone are formed from carbohydrates by different bacilli (butyl bacteria) belong in this group. The term butyl bacteria as a generic name for microbes producing the genetically related substances of the four-carbon series was proposed in 1921" and has been applied since then. The approximate course of these reactions is shown by the following formulations which, however, do not explain the mechanism ... 

Important results have recently been obtained by Simon. Among other things he ascertained that glycerol yields butyric acid. The formation of four-carbon compounds from six-carbon substrates is independent of the grouping (aldehyde, hydroxyl, carboxyl, phosphory-lated hydroxyl) at the first carbon atom of the molecule. L-Rhamnose and D-arabitol are fermented, but not n-arabinose and D-sorbitol. In contrast to the studies of Underkofler and Hunter, " L-sorbose has been found fermentable. Results obtained with fresh and acetone-dried Cl. hutylicum are identical in principle. 

Lipase splits fatty acids from glycerol to produce free fatty acids, for example, butyric acid. If the original fat is butterfat then at low levels this produces a buttery or creamy flavour. As the free fatty acid content is increased, this strengthens the flavour to cheesy . Normally in toffees free butyric acid is not a problem at any practical level, possibly because of losses during cooking. Other free fatty acids have different flavours. Laurie acid, which is found in nuts, tastes of soap. This is not too surprising as soap often contains sodium laurate. Laurie fat sources, such as hardened palm kernel oil, are often used as a substitute for butter another potential source is nuts, which are sometimes combined with toffee. In any of these cases, lipolytic activity can shorten the shelf life of the product or render it totally unacceptable. 

Butyric acid is obtained from the animal charcoal which has -been used in the purification of glycerol, in which it exists as calcium butyTate. It is also formed by subjecting to fermentation. a mixture composed of glucose, water, chalk, and cheese or gluten. The calcium butyrate is decomposed by HjS04, and the butyric -acid separated by distillation. 

The structures of the acids are derived from their syntheses from propyl bromide and isopropyl bromide, respectively. Normal butyric acids occurs in combination with glycerol in butter (whence the name of the acid), and in other fats. It is formed as the result of the fermentation of sugars, fats, and other sub-... 

Propylene is, next to ethylene, the most important basic chemical to produce not only polypropylene but also other intermediates for example propylene oxide and acrylonitrile. Just like ethylene, propylene can be produced via a hydrocarbon feedstock produced from a biomass [35-37]. Bio-glycerol produced as a byproduct of biodiesel can be dehydrogenated to produce propylene [48]. Bio-based ethylene can be dimerized to produce n-butene, which can then react with remaining ethylene via metathesis to produce propylene [49]. The use of fermentation products of biomass such as 1-butanol [50] enables the formation of n-butene, followed by a subsequent methathesis [49]. Alternatively, hydrothermal carboxylate reforming of fermentation products such as butyric acid or 3-hydroxybutyrate is also proposed as a viable option to propylene [51]. 

Butyric fatty acid is specific for milk fat of ruminant animals and is responsible for the rancid flavor when it is cleaved from glycerol by lipase action. 

Many other chemicals can be obtained from both yeast and bacteria fermentation of sugars and pulp mill effluents. Potential fermentation products from wood hydrolysates include acetone, organic acids (acetic, butyric, lactic), glycerol, butanediol, and others.42... 

Three different fatty acids can occur from 27 different mixed triglycerides. To simplify the description, one- or two-letter abbreviations of fatty acids are used, such as B = butanoic (butyric), D = decanoic (capric or caprinic), H = hexanoic (caproic), L = linoleic, La = lauric, Ln = linolenic, M = myristic, O = oleic, Oc = octanoic (caprylic), P = palmitic, Po = palmitoleic, S = saturated, St = stearic, U = unsaturated and V = vaccenic. For example, the mixed triacylglycerol esterified with palmitic acid in position s -l, with stearic acid in the position sn-2 and oleic acid in the position sn-3 of glycerol is then called l-palmitoyl-2-stearoyl-3-oleoyl-s -glycerol (abbreviated to s -PStO). Racemate is a mixture of s -PStO and and s -OStP in a molar ratio of 1 1... 

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