Starch ester
Starch esters are derivatives of starch that result from the esterification of hydroxyl groups with acids. In a polymer-analogous reaction , there is a change in the functional group. This makes it possible to change the properties of the starch. The starch for this is mostly obtained from potatoes, corn or wheat. Some starch esters are used today as a food additive .
Manufacturing
The starch esters are synthesized from starch and carboxylic acid anhydrides in a polymer-analogous reaction . An alkaline pretreatment of the starch is necessary for the synthesis of starch sulphate. This is usually followed by a reaction with acid chlorides. Since not all hydroxyl groups react in this reaction, mixtures are formed with different degrees of substitution . The degree of substitution of the individual starch components within a polymer can also vary.
The schematic synthesis of acetylated starch ( E 1420 ) in the polymer-analogous reaction of starch with acetic anhydride serves as an illustration :
Analogous mixtures result from the following reactions:
- Starch sulfates are produced by reacting starch that has been pretreated with an alkaline solution with chlorosulfonic acid.
- Starch nitrates are produced by reacting starch with concentrated sulfuric acid (H 2 SO 4 ) and nitric acid (HNO 3 ).
- Starch exanthates are produced by reacting starch pretreated with alkaline agents with carbon disulfide (CS 2 ).
- Starch citrates are made by reacting starch with citric acid.
- Starch succinates are made by reacting starch with succinic anhydride .
- Starch phosphates are made by reacting starch with monosodium orthophosphate or disodium orthophosphate. They can also be obtained by dry heating of starch with phosphates or phosphorus oxychloride to 120-175 ° C in a basic environment.
- Starch sodium octenyl succinate ( E 1450 ) is produced by reacting starch with octenyl succinic anhydride.
application
Starch esters are chemically modified starches that are used industrially as food additives , among other things . They are mainly used in frozen and canned dishes. The starch esters are mostly used for freeze-thaw stabilization or to stabilize the consistency. They are also used as a protective coating for perishable products such as dried fruits , for encapsulating flavors and for fruit fillings in pralines. They are also used as thickeners and stabilizers for baked goods. The exact areas of application of the individual starch esters can be found in the respective article. For example, starch phosphates are used especially for acidic foods that are strongly heated (sterilized). In addition to monostarch phosphate ( E 1410 ) and distarch phosphate ( E 1412 ), phosphated and acetylated distarch phosphate ( E 1414 ) are also used. The phosphated starch derivative is labeled ( E 1413 ).
Individual evidence
- ↑ a b c d e Entry on starch esters. In: Römpp Online . Georg Thieme Verlag, accessed on May 26, 2020.
- ↑ a b ZZulV : Annex 4 (to Section 5, Paragraph 1 and Section 7) Limited additives .
- ↑ Entry on starch nitrate. In: Römpp Online . Georg Thieme Verlag, accessed on May 26, 2020.
- ^ H. Klaushofer, E. Berghofer, W. Steyrer: Starch citrate - production and application-technical properties . In: Starch, 1978, Vol. 30, No. 2, pp. 47-51, https://doi.org/10.1002/star.19780300204 .
- ↑ Frank Böttger: Synthesis and characterization of new starch derivatives for clinical use . Kassel, 2003, p. 29, https://kobra.uni-kassel.de/handle/123456789/700 .
- ↑ Entry on starch phosphates. In: Römpp Online . Georg Thieme Verlag, accessed on May 26, 2020.
- ↑ a b Entry on monostarch phosphate. In: Lebensmittellexikon.de Frank Massholder, accessed on March 15, 2016.
- ↑ a b Hans-Dieter Belitz , Werner Grosch , Peter Schieberle : Textbook of food chemistry . 6th completely revised edition. Springer, Berlin / Heidelberg 2008, ISBN 978-3-540-73201-3 , doi : 10.1007 / 978-3-540-73202-0 .
- ^ Joint FAO / WHO Expert Committee on Food Additives (JECFA), Monograph for STARCH SODIUM OCTENYL SUCCINATE , accessed on December 9, 2014.