Vinegars

Manufactured by the liquid-phase oxidation of ethanal at 60 C by oxygen or air under pressure in the presence of manganese(ii) ethanoate, the latter preventing the formation of perelhanoic acid. Another important route is the liquid-phase oxidation of butane by air at 50 atm. and 150-250 C in the presence of a metal ethanoate. Some ethanoic acid is produced by the catalytic oxidation of ethanol. Fermentation processes are used only for the production of vinegar. 

Caustic alkalis. Dilute by drinking much water, followed by vinegar, lemon or orange juice, or solutions of lactic acid or citric acid. Milk may then be given but no emetics. 

Although these humble origins make interesting historical notes m most cases the large scale preparation of carboxylic acids relies on chemical synthesis Virtually none of the 3 X 10 lb of acetic acid produced m the United States each year is obtained from vinegar Instead most industrial acetic acid comes from the reaction of methanol with carbon monoxide... 

Fig. 1. An amplified outline scheme of the making of various wiaes, alternative products, by-products, and associated wastes (23). Ovals = raw materials, sources rectangles = wines hexagon = alternative products (decreasing wine yield) diamond = wastes. To avoid some complexities, eg, all the wine vinegar and all carbonic maceration are indicated as red. This is usual, but not necessarily tme. Similarly, malolactic fermentation is desired in some white wines. FW = finished wine and always involves clarification and stabilization, as in 8, 11, 12, 13, 14, 15, 33, 34, followed by 39, 41, 42. It may or may not include maturation (38) or botde age (40), as indicated for usual styles. Stillage and lees may be treated to recover potassium bitartrate as a by-product. Pomace may also yield red pigment, seed oil, seed tannin, and wine spidts as by-products. Sweet wines are the result of either arresting fermentation at an incomplete stage (by fortification, refrigeration, or other means of yeast inactivation) or addition of juice or concentrate.

Maturation is conducted in closed, full containers to prevent oxidation and aerobic growth of microorganisms. Etee air contact with low alcohol wine soon leads to vinegar. Except for those sherry types already mentioned, wines ate exposed to air minimally and temporarily. During transfers incident to bulk storage and processing, some air exposure is almost inevitable, mote in total the longer the wine is held. In the cases of white and pink table wines, it is ordinarily as neat zero as possible, and stainless steel or other impermeable containers, inert gas headspace, etc ate employed. Red wines withstand and even benefit from small but repeated exposures to air. 

Theophrastos (272—287 Bc) studied the utilisation of acetic acid to make white lead and verdigris [52503-64-7]. Acetic acid was also weU-known to alchemists of the Renaissance. Andreas Libavius (ad 1540—1600) distinguished the properties of vinegar from those of icelike (glacial) acetic acid obtained by dry distillation of copper acetate or similar heavy metal acetates. Numerous attempts to prepare glacial acetic acid by distillation of vinegar proved to be in vain, however. 

Lavoisier beUeved he could distinguish acetic acid from acetous acid, the hypothetical acid of vinegar, which he thought was converted into acetic acid by oxidation. Following Lavoisier s demise, Adet proved the essential identity of acetic acid and acetous acid, the latter being the monohydrate, and in 1847, Kolbe finally prepared acetic acid from the elements. 

Mustard is marketed in three forms, ie, as a seed as a prepared blend of ground mustard seed, vinegar, salt, sugar, and other spices and as powdered dry mustard, also known as ground mustard or mustard flour. The seeds of the white or yellow mustard add pungency to any preparation, and that of the black mustard is required for aroma. Mustard is the largest volume spice imported into the United States and its use covers almost every flavor category except dessert items. 

Bl cetyl. Biacetyl [431-03-8] (2,3-butanedione) is a greenish yeUow liquid with a quinone odor. Biacetyl occurs naturally in bay oil and is readily soluble in organic solvents. It is a constituent of many food aromas, eg, butter, and is commonly used to flavor margarine. Flavor-grade biacetyl was available at 20.40/kg in July 1993, and is used as an odorant for coffee, vinegar, tobacco, and in perfumes. 

BenZenetetrol. 1,2,3,4-Tetiahydioxybenzene 01 apionol (59) forms needles from benzene (mp 161°C). It is easily soluble in water, diethyl ether, ethanol, and glacial acetic acid and is spariagly soluble ia benzene. It has been identified as one of the many constituents of wood—vinegar distillate (202). 

Dispersed Systems. Many fluids of commercial and biological importance are dispersed systems, such as soflds suspended in Hquids (dispersions) and Hquid-Hquid suspensions (emulsions). Examples of the former include inks, paints, pigment slurries, and concrete examples of the latter include mayonnaise, butter, margarine, oil-and-vinegar salad dressing, and milk. Blood seems to fall in between as it is a suspension of deformable but not hquid particles, and it does not behave like either a dispersion or an emulsion (69) it thus has an interesting rheology (70). 

Egyptian papyms bonded with a starchy adhesive has been dated to 3500—4000 BC. Pliny the Elder (23—74 ad) described Egyptian use of wheat starch modified by boiling in vinegar to produce a smooth surface for papyms documents. 

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