Generation of peroxyhydroxycarboxylic acid and the use thereof
Peroxyhydroxycarboxylic acid forming compositions and methods for forming peroxyhydroxycarboxylic acids, preferably in situ, using the peroxyhydroxycarboxylic acid forming compositions are disclosed. Methods of using the peroxyhydroxycarboxylic acids, including for treating a surface or a target in need of antimicrobial or sanitizing treatment are also disclosed. Particular applications of using odor-free, low volatility peroxyhydroxycarboxylic acid sanitizers for direct food contact are disclosed.
1. A method for forming a peroxyhydroxycarboxylic acid comprising:
contacting reagents comprising a lactone of an alphahydroxycarboxylic acid with an alkalinity source and hydrogen peroxide or a substance that generates hydrogen peroxide when in contact with a liquid, to form a liquid that comprises the peroxyhydroxycarboxylic acid and has a pH below about 7 within about 5 minutes after the contact between the reagents; and
generating at least about 1 ppm of the peroxyhydroxycarboxylic acid at the point of contacting to within less than 1 minute.
2. The method of claim 1 , wherein the lactone of the alphahydroxycarboxylic acid is a diester of lactone.
3. The method of claim 2 , wherein the alphahydroxycarboxylic acid is lactic acid or glycolic acid, and wherein the lactone of the alphahydroxycarboxylic acid is correspondingly lactide or glycolide.
4. The method of claim 1 , wherein the alkalinity source comprises an alkaline metal hydroxide, an alkali metal silicate, an alkali metal carbonate, borate, amine, amide or other basic nitrogen sources or mixtures thereof.
5. The method of claim 1 , wherein the reagents are contacted to form a liquid solution comprising the peroxyhydroxycarboxylic acid in amounts from about 0.1 ppm to about 100,000 ppm and/or wherein the peroxyhydroxycarboxylic acid has less than about 1 KPa vapor pressure at 20° C.
6. The method of claim 5 , wherein the reagents are contacted to form a liquid solution comprising the peroxyhydroxycarboxylic acid from about 10 ppm to about 50,000 ppm of the peroxyhydroxycarboxylic acid.
7. The method of claim 1 , wherein the liquid that comprises the peroxyhydroxycarboxylic acid comprises at least about 10 ppm, at least about 100 ppm, or at least about 1,000 ppm peroxyhydroxycarboxylic acid within about 1 minute of the contact time.
8. The method of claim 1 , wherein the liquid that comprises the peroxyhydroxycarboxylic acid comprises at least about 100 ppm, at least about 1,000 ppm, or at least about 10,000 ppm peroxyhydroxycarboxylic acid within about 5 minutes of the contact time.
9. The method of claim 1 , wherein the reagents are contacted at a temperature ranging from about 4° C. to about 60° C. and at a pH between about 7 to about 12.
10. The method of claim 1 , wherein the formed liquid that comprises the peroxyhydroxycarboxylic acid has a pH below about 6 within about 5 minutes after the contact between the reagents.
11. The method of claim 1 , wherein the peroxyhydroxycarboxylic acid is generated in situ.
12. The method of claim 1 , wherein the reagents are contacted in the presence of a solvent to disperse the reagents that are in a powder form and/or a catalyst or an enzyme that catalyzes formation of the peroxyhydroxycarboxylic acid.
13. The method of claim 1 , wherein the reaction to form the peroxyhydroxycarboxylic acid does not comprise an enzyme and/or catalyst.
14. The method of claim 1 , wherein the peroxyhydroxycarboxylic acid is not combined with a stabilizing agent and/or a stabilizing agent is not included as a reagent in the reaction to generate the peroxyhydroxycarboxylic acid.
15. The method of claim 1 , wherein the reagents further comprise a stabilizing agent for hydrogen peroxide and/or a pH buffering agent.
16. The method of claim 1 , wherein contacting the reagents further comprises contacting the hydrogen peroxide with multiple dosages of the lactone of an alphahydroxycarboxylic acid sequentially.
17. The method of claim 1 , wherein an additional C1-C22 peroxycarboxylic acid is formed in the liquid comprising the peroxyhydroxycarboxylic acid, or wherein a preformed C1-C22 peroxycarboxylic acid composition is added to the liquid comprising the peroxyhydroxycarboxylic acid.
18. The method of any one of claim 17 , wherein an ester precursor and/or a carboxylic acid precursor of the additional C1-C22 peroxycarboxylic acid is added to the reagents and/or added to the liquid comprising the peroxyhydroxycarboxylic acid to generate the additional C1-C22 peroxycarboxylic acid.
19. The method of claim 18 , wherein the precursors are provided as powders and/or liquids, wherein any powder reagents are combined into a single composition prior to the contacting, and wherein any liquid reagents are kept separately prior to the contacting to generate the peroxyhydroxycarboxylic acid.
20. The method of claim 1 , wherein the lactone of the alphahydroxycarboxylic acid and the hydrogen peroxide or a substance that generates hydrogen peroxide are kept separately prior to said contacting, or wherein the alkalinity source and the hydrogen peroxide or a substance that generates hydrogen peroxide are kept separately prior to said contacting.