# Calculating pH in the aqueous phase of smoked herring

3 replies to this topic

### #1 Conny T

Conny T

• IFSQN Associate
• 45 posts
• 4 thanks
0
Neutral

• Denmark

• Gender:Female
• Interests:Photography, nature

Posted 16 May 2012 - 01:06 PM

Conducting a risk-analysis for producing smoked herrings in vegetable oil I have come to think if I can calculate the pH in the aqueoous phase of the fish?

As product is in oil it is hard measuring a pH that we can trust. But I thought that if we measure dried matter and acid on the herring we would be able to find the acid in the aqueous phase - and then calculate the pH from that......

Do I have a point?

### #2 Simon

Simon

IFSQN...it's My Life

• 12,546 posts
• 1321 thanks
732
Excellent

• United Kingdom

• Gender:Male
• Location:Manchester
• Interests:Married to Michelle, Father of three boys (Oliver, Jacob and Louis). I enjoy cycling, walking and travelling, watching sport, especially football and Manchester United. Oh and I love food and beer and wine.

Posted 17 July 2012 - 07:49 PM

Can anyone assist Conny with this technical question?

Thanks,
Simon

Get FREE bitesize education with IFSQN webinar recordings.

https://www.ifsqn.com/fsf/Free%20Food%20Safety%20Videos.xlsx

Check out IFSQN’s extensive library of FREE food safety videos
https://www.ifsqn.com/food_safety_videos.html

### #3 MicroMike

MicroMike

• IFSQN Active
• 8 posts
• 4 thanks
0
Neutral

• Scotland

Posted 21 July 2012 - 06:29 PM

It's possible, but the easiest might be just to macerate the product, use a separation funnel and wait for the oil and water to separate out, then measure the pH of the water.If you know the acid concentration, wet weight and dry weight I.e. how much water is there and the acid concentration, you can work out the concentration of hydrogen ions. pH is -log10 of the hydrogen ion concentration in water. You can only do it if you know what type acid is present because they can dissociate into hydrogen ions and anions differently.
HTHMike

 Thanked by 1 Member:

### #4 Conny T

Conny T

• IFSQN Associate
• 45 posts
• 4 thanks
0
Neutral

• Denmark

• Gender:Female
• Interests:Photography, nature

Posted 23 July 2012 - 07:17 AM

We do not have the equipment for separation but can analyze the acid. Will try to do it this way. Thanks

#### 0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users