26 replies to this topic

[GMO]

Oh that's interesting; when you say spectral interference, the ones I've used are based on IR spectrometry which wouldn't work for He as there is no bond there.  Is it a different one they use?

Indeed, the packaging we were testing was very robust.  You could actually see the packs puff up significantly in the CO2 detector but wouldn't be as distorted by the water one, we just couldn't get that kind of pressure.  Perhaps that's why our different observations.

[karamjit7828]

I have experience with MAP in cheese. 70/30 and 100% CO2 are both common gas mixes. The purpose of the CO2 is it gets absorbed into the cheese to a level and has an antimicrobial effect. In my experience both work but I suspect you have more CO2 in the grated to maximise the amount for the higher surface area.

The downside to 100% CO2 can be if all the gas is absorbed then it can pull in the packaging like a vacuum which isn’t always desired but if you’re putting enough in that’s possibly not an issue.

So to my mind that’s the reason for the difference. Higher mould risk on grated due to the higher surface area meaning you’re putting in more CO2 to maximise the antimicrobial impact.

The limit on oxygen seems ok. I’ve seen levels ranging from 0.5-1%. From experience 1% is possibly too high. 0.6% might be based on the machinery you have. If you can reliably get it below 0.5% I would.

But probably the most important check is on leaks. As you’re using CO2 there are some great bits of kit to detect leaks based on IR sensors. I think from memory they’re called Dansemsor Leakpointers? Basically they pull a vacuum on test pack(s) and test for CO2 presence in the headspace. Much better than those bubble tanks as they’re more sensitive and if you have several sealing jaws you can test more than one pack at a time.

Are you able to tell me the supplier name for food grade gases?