Preservation and bleaching of sliced mushrooms with hydrogen peroxide

According to the article [Extending the Shelf Life of Fresh Sliced Mushrooms](http://www.teagasc.ie/research/reports/foodprocessing/4196/eopr-4196.pdf), it states that 5% (v/v) hydrogen peroxide is an effective means for the preservation of sliced mushrooms.


In regards to the preservation:



> 
> In the USA hydrogen peroxide
>  is an approved bactericide for some dairy products and is used for disinfecting fruit
>  and vegetables. Its activity is due to its oxidising effects on
>  bacteria and it also bleaches mushrooms during the soaking period.
> 
> 
> 


**How does oxidising effects cause the bleaching, hence preservation of sliced mushrooms?**




Hydrogen peroxide is quite a strong oxidizer. First, let's address the bleaching effect: It bleaches by oxidizing colored compounds, making them colorless. From [Wikipedia](https://en.wikipedia.org/wiki/Bleach#Mechanism_of_action):



> 
> An oxidizing bleach works by breaking the chemical bonds that make up the chromophore. This changes the molecule into a different substance that either does not contain a chromophore, or contains a chromophore that does not absorb visible light. This is the mechanism of bleaches based on chlorine.
> 
> 
> 


This is also the mechanism of hydrogen peroxide as a bleach, since both chlorine-based bleach and hydrogen peroxide are oxidizers.


As for the antibacterial effect: hydrogen peroxide in this particular concentration (5%) may or may not be effective against bacteria (and viruses, fungi, etc.) due to the presence of the enzyme [catalase](https://en.wikipedia.org/wiki/Catalase) in some bacteria and fungi. In those organisms which it is effective against, hydrogen peroxide would probably work by causing [oxidative stress](https://en.wikipedia.org/wiki/Oxidative%20stress) in the organism.


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