Lactic acid. Table

Stereoisomers of lactic acid produced by lactic acid bacteria are useful for species identification. The optical configuration of lactic acid (Table 13.1) depends on the stereospecificity of the LDH. Some microorga-... 

Other organic acids which have been tested for their impact on iron absorption include oxalic, succinic, fumaric and lactic acid (Table V). The iron from iron phytates was bioavailable only in the soluble monoferric form, whereas the less soluble diand tetra-ferric phytates were very poor iron sources (37,... 

Reviewing the primary tastes in beer its sourness will be measured either as its pH (3-8-4-7) or as its titratable acidity. The level of acetic acid reported for normal beers (57-145 ppm) is below the taste threshold (400 ppm) and the same is true of lactic acid (Table 22.7). Infection of beer with microorganisms such as Acetobacter and Lactobacillus spp. may reduce the pH and produce a sour taste. Thus with lambic and gueuze beer the pH may drop to pH 3 2. The level of acetic acid in these beers is 2 6-6-9 times the taste threshold and the level of lactic acid is 5-8-8-6 times its taste threshold [24]. 

Synthesis and Production of Poly(lactic Acid) Table 2.1 Physical Properties of Lactic Acid... 

Draw a flowchart that diagrams a method for the resolution of racemic 2-hydroxypropanoic acid (lactic acid, Table 5-1), using... 

In addition to alcohoHc fermentation, a malolactic fermentation by certain desirable strains of lactic acid bacteria needs to be considered. Occasionally, wild strains produce off-flavors. Malolactic fermentation is desirable in many red table wines for increased stabiUty, more complex flavor, and sometimes for decreased acidity. Selected strains are often added toward the end of alcohoHc fermentation. AH the malic acid present is converted into lactic acid, with the resultant decrease of acidity and Hberation of carbon dioxide. Obviously this has more effect on the acidity the more malic acid is present, and this is the case in wine from underripe, too-tart grapes. Once malolactic fermentation has occurred, it does not recur unless another susceptible wine is blended. 

Physical Properties. Pure, anhydrous lactic acid is a white, crystalline soHd with a low melting poiat. However, it is difficult to prepare the pure anhydrous form of lactic acid generally, it is available as a dilute or concentrated aqueous solution. The properties of lactic acid and its derivatives have been reviewed (6). A few important physical and thermodynamic properties from this reference are summarized ia Table 1. 

A Acylsarcosinates. Sodium A/-lautoylsarcosinate [7631-98-3] is a good soap-like surfactant. Table 4 gives trade names and properties. The amido group in the hydrophobe chain lessens the interaction with hardness ions. A/-Acylosarcosinates have been used in dentifrices (qv) where they ate claimed to inactivate enzymes that convert glucose to lactic acid in the mouth (57). They ate prepared from a fatty acid chloride and satcosine ... 

Table 5-1. Enantioselectivities determined for several drugs. All experiments were performed at room temperature, except those marked with, which were performed at 4 °C. In some cases a lipophilic anion was used to facilitate the solubilization of the drug in the organic phases (PFj = hexafluorophosphate BPh = tetraphenyl borate). DHT = dihexyl tartrate DBT = dibenzoyl tartrate PLA = poly (lactic acid). ...

Lactic acid and levulinic acid are two key intermediates prepared from carbohydrates [7]. Lipinsky [7] compared the properties of the lactide copolymers [130] obtained from lactic acid with those of polystyrene and polyvinyl chloride (see Scheme 4 and Table 5) and showed that the lactide polymer can effectively replace the synthetics if the cost of production of lactic acid is made viable. Poly(lactic acid) and poly(l-lactide) have been shown to be good candidates for biodegradeable biomaterials. Tsuji [131] and Kaspercejk [132] have recently reported studies concerning their microstructure and morphology. 

Some of the most notable contributions were (a) the discovery of numerous strains of lactic acid bacteria including those listed in Table XI, (b) the elaboration of the mineral... 

Table XI. History of Discovery of Common Lactic Acid Bacteria (16)...

Sf.i f-Test 10.9A Calculate the pH and percentage deprotonation of 0.50 m aqueous lactic acid. See Table 10.1 for Ka. Be sure to check any approximation to see whether it is valid. 

Use Table 10.9 to determine the percentage deprotonation of 1.00 m aqueous lactic acid. At what temperature will the solution freeze (Assume that the density of the solution is 1.00 g-cm 3.)... 

Polylactates are an interesting class of biodegradable polymers which may be made from either renewable or petroleum feedstocks. The synthesis of lactic acid raises real issues concerning the relative greenness of the renewable and non-renewable (HCN) route as discussed in Chapter 2. A summary comparison of the greenness of both routes is shown is Table 6.4. Without a full LCA the choice of route on environmental grounds is not easy and at least partly depends on plant location and raw material availability. 

Table 6.4 Comparison of renewable and non-renewable routes to lactic acid...

Table 1 shows the dry weight of substrate, and amounts of HCl aqueous solution for pretreatment, cellulase and suspension broth for the lactic acid fermentation with ESS. The initially supplied amount of bean curd refuse in dry weight basis was changed from 10 to 150 g to examine the influence of substrate loading. The amount of cellulase was increased against initial substrate loading. And also, the amoimt of 0.1 mol/1 HCl was increased against... 

Table 1 Operating condition in the lactic acid fermentation with SSF using HCl-pretreated substrate...

The selective inclusion properties of 40 (Table 6) offer several possibilities of compound separation which are of interest in analytics and for preparation purposes37). The separation of methanol from a mixture with ethanol, or of propionic aldehyde from propionic acid, or of 2-chloropropionic acid from propionic acid or lactic acid, etc., are a few examples. 

---