Sorbic acid preservatives

Problem 17.31 Use aldol condensations to synthesize the following useful compounds from cheap and readily available compounds (a) the food preservative sorbic acid, CHjCH=CH—CH==CH—COOH (fe) 2-ethyl-l-hexanol (c) 2-ethyl-l,3-hexanediol, an insect repellant (d) the humectant pentaerythritol, CCCHjOHjo. ... 

Additives/Preservatives sorbic acid, benzoic add, BHT, BHA, tocopherol... 

A variety of additives are incorporated into the dispersions as surfactants (Tween 80, sodium lauryl sulfate, polyoxyethylene nonyl phenyl ether, cetyl alcohol, and Pluronic F-68), plasticizers (dibutyl sebacate, oleic acid, and Myvacet 9-40), pigments, antiadherents (fumed silica), anticoagulant (Myvacet 9-40), preservatives (sorbic acid), and stabilizers (ammonia). ... 

Plumridge, A., Hesse, S.J., Watson, A.J., Lowe, K.C., Stratford, M., and Archer, D.B. 2004. The weak acid preservative sorbic acid inhibits conidial germination and mycelial growth of Aspergillus niger through intracellular acidification. Applied and Environmental Microbiology 70 3506-3511. 

Holyoak, C.D., Stratford, M., McMullin, Z., Cole, M.B., Crimmins, K., Brown, A.J.P., and Coote, P. 1996. Activity of the plasma-membrane H+-ATPase and optimal glycolic flux are required for rapid adaptation and growth in the presence of the weak acid preservative sorbic acid. Applied and Environmental Microbiology 62 3158-3164. 

In the field of food analysis, a number of successful applications of analytical isotachophoresis have been reported (e.g. determination or organic acids in juices 9,76,99,112-114) yoghouTts wincs , and tea . The short time required for the separation and the minimum necessary treatment of the samples are the main advantages of these analyses. Thus both preservatives (sorbic acid and benzoic acid) and the initial components of the samples (ascorbic, isoascorbic, citric, lactic, aconitic, aspartic and glutamic acids, theanine etc.) may be determined. 

The oxidative dehydrogenation of alcohols represents key steps in the synthesis of aldehyde, ketone, ester, and acid intermediates employed within the fine chemical, pharmaceutical, and agrochemical sectors, with allylic aldehydes in particular high-value components used in the perfume and fiavoring industries [1]. For example, crotonaldehyde is an important agrochemical and a valuable precursor for the food preservative sorbic acid, while citronellyl acetate and cinnamaldehyde confer rose/fruity and cinnamon flavors and aromas, respectively. There is also considerable interest in the exploitation of biomass-derived feedstocks such as glycerol (a by-product of biodiesel synthesis from plant or... 

The solubility of active substances often depends on the pH (see Sect. 5.8.1). By adjusting the pH, a solution or a suspension may be prepared (see Sect. 19.1.1). The pH can affect the stability of an active substance or excipient. For example, the hydrolysis rate of esters depends on the pH (see Sect. 22.2.1). The pH must be taken into account for the preservation of an oral solution. The preservative sorbic acid is only effective at a pH <5.5 and the preservative methyl parahydroxybenzoate undergoes hydrolysis at pH > 8. 

The efficacy of a preservative is pH dependent. Therefore the pH value of the ophthalmic solution determines the choice of the preservative. Sorbic acid and benzoic acid present in other dosage forms are active at a pH value lower than 5, and therefore unsuitable in most ophthalmic solutions. 

The ionisable preservatives sorbic acid (see Fig. 23.16) and benzoic acid (see Fig. 23.17) are only active as the undissociated form, because this passes the bacterial membrane. 

Electrospun nanofiber layers were also used as elution substrate for ESI-MS via the TLC-MS Interface. The preservatives sorbic acid m/z 223 [2M-H] ),... 

Moors, M., C. R. R. R. Teixeira, M. Jimidar, and D. L. Massart. 1991. Solid phase extraction of the preservatives sorbic acid and benzoic acid, and the artificial sweeteners aspartame and saccharine. Anal. Chim. Acta 255 177-186. 

---