Preservatives
Preservatives are substances and mixtures that are used for preservation .
properties
Preservatives are antimicrobial biocides used to kill or inhibit the growth of microorganisms . They are used when physical methods alone are not enough. The spectrum of possible compounds has not changed for a long time, as it is difficult to find cheap substances with broad activity and low toxicity to mammals. When using weak acids, their pK value and an acidic pH value in the food are necessary, since only undissociated molecules can penetrate the cell membrane into the interior of microorganisms.
One distinguishes
- Food additives that prevent food spoilage e.g. B. to prevent bacteria , yeast and mold . They play an important role in food preservation and prevent dangerous diseases like botulism and listeriosis . Preservatives must be declared by their generic name , name and E number (200 to 299).
- Cosmetic ingredients such as parabens , benzoic acid or methylisothiazolinone , which are used as preservatives. Preservation is necessary for many cosmetics . However, only preservatives may be used that are permitted under Regulation (EC) No. 1223/2009 on cosmetic products .
- pharmaceutical auxiliaries for drug preservation .
- Wood preservatives .
In the event of missing or insufficient conservation, considerable damage can result. Inadequately preserved foods can lead to illness of the consumer when consumed. Again and again it comes B. Salmonella infections through the consumption of food. The carcinogenic effect of aflatoxins, which are excretion products of mold, is insidious. If you prevent the development of mold , you also reduce the formation of aflatoxins . In addition to chemical preservation using preservatives, there are also physical methods of preservation which are still of considerable technical importance. This includes conservation through
- Heating ( pasteurizing , sterilizing )
- Dehydration ( drying )
- Air exclusion (paraffin layer for cheese, etc., vacuum sealing ) and
- Freezing (≤ −18 ° C ).
Web links
- Cosmetics Ordinance - Annex 6 - Preservatives for cosmetic products ( Memento from January 6, 2014 in the Internet Archive )
Individual evidence
- ↑ Belitz, Grosch, Schieberle: Textbook of food chemistry. Springer, 2008, p. 462, doi : 10.1007 / 978-3-540-73202-0_9 .
- ^ Bertram Philipp, Peter Stevens: Grundzüge der Industrielle Chemie , VCH Verlagsgesellschaft mbH, 1987, pp. 335–338, ISBN 3-527-25991-0 .