Advice please- Vacuum Packing- fascia/blood taking on green/blue hue instantly

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geoffw

geoffw

Well-Known Member
I am experiencing a vacuum packing issue and would welcome advice please...

The meat is all handled to the nec standards, professionally chilled (progressive 7C,4C,2C) and butchered by local butcher.
This problem occurs whether it's a fallow calf butchered and packed within 3 days, or an older beast hung for 7-10days.

Using a commercial (Buffalo) vac packer, in styrene foam trays (I can find no biodegradable alternative) +blood soak pads, any fascia takes on a (coppery?) green/ (iron?) blue hue within 30mins. Any blood that leaches out turns greeny/blue shortly afterwards. This discolouration gets progressively more noticable until the UBD 7 days later.

If I open the pack to inspect then the meat is perfect- red/pink as fresh as the day it was butchered and there is no smell to either the meat or the blood.

Can anyone tell me what is going on here and how to prevent it please? Many, many thanks in advance.

@VSS you're wise on these matters I think? Any thoughts please?

@willie_gunn fyi
 
Lifted from a Google

As far as the greenish/blue coloring, the tint of the packaging may also be a contributing factor, but it is more than likely that the myoglobin started to break down and oxidize creating metmyoglobin which can give a brownish/green hue to the meat. This coupled with the fact that some meat packing plants expose the meats to carbon-monoxide for long periods of time to preserve color in the meat display case, may also cause some additional discoloring during oxidation
 
sh1kar said:
Lifted from a Google

As far as the greenish/blue coloring, the tint of the packaging may also be a contributing factor, but it is more than likely that the myoglobin started to break down and oxidize creating metmyoglobin which can give a brownish/green hue to the meat. This coupled with the fact that some meat packing plants expose the meats to carbon-monoxide for long periods of time to preserve color in the meat display case, may also cause some additional discoloring during oxidation
Click to expand...
Thank you @sh1kar
Armed with a possible causal mechanism I can narrow my search for a solution.
 
75 said:
What happens if you vac pac without either the foam tray or the pad? I'd bet it's one or other of those causing it.
Click to expand...
I hear you, and will give it a go @75 .
The issue is that the local farm shops all want both of those packaging materials.
The foam trays were from Weschenfelder, so should be good, I'll give Rob a call and see what he knows.
Will report back.
 
I use the same foam trays from weschenfelder and use absorbent pad too but not experiencing any issues.
Also, yeast and mould can grow on low temperature, maybe worth a microbiological test?
Plus worth to have a look to the vac packer's sucking tube, if your one is a portable one, as if any liquid/blood gets in and gets trapped there, then that can cause problems
 
South West Stalkers said:
I use the same foam trays from weschenfelder and use absorbent pad too but not experiencing any issues.
Also, yeast and mould can grow on low temperature, maybe worth a microbiological test?
Plus worth to have a look to the vac packer's sucking tube, if your one is a portable one, as if any liquid/blood gets in and gets trapped there, then that can cause problems
Click to expand...
Thank you @South West Stalkers, good to know re the trays and pads.

One question- do you vacuum pack to rock hard?
I ask based on some reading @willie_gunn kindly sent me "The fact that the meat doesn't change colour makes me wonder whether you have the vacuum set too strong. I had a quick look at this link, which speaks about myoglobin (what gives meat its red colour). It was this sentence that tweaked my interest: "The use of a plastic wrap that allows oxygen to pass through it helps ensure that the cut meats will retain this bright red color". The ziploc bag [what I previously used] is not airtight, so the oxygen will still get through, whereas a strong vacuum will remove all oxygen and I wonder if that prevents the formation of myoglobin? Just a guess, and I am in no way a scientist!"

I'm pretty confident it's this/a chemical reaction rather than microbial because it's instantaneously evident and on the face of fresh slices, even though it seems somewhat counter-intuitive that this could be due to the absence of oxygen!

Mine's a mouth sealer rather than a sucking tube, but thank you for the suggestion.
 
What happens if you vacuum, but cease before it has completely removed all the air? My Buffalo sealer let’s me stop at any point by pressing the “Seal” button.

Just thinking of ways to isolate the problem.
 
Thank you for all the comments and ideas.
Reduced vac- yes, I wondered too and have been experimenting with that @willie_gunn, but don't have a definitive view yet- will revert.
@csl I think you're right, and some of the US facilities use CO2 and even, I read (really!), CO, since it binds to the haemoglobin better than O2, as many will know.

I don't have answer for you yet, but... I shot a small fallow calf on Sunday that didn't justify butchery charges, so I kept it in my chiller 7C-4C-3C and did it myself on Wednesday, vacuum packing the sirloin steaks (+trays+pads) at the same time- they stayed red. I left the haunches hanging in the chiller and seamed them on Saturday mornign prior to the farmers market- they have also stayed red once vac packed.

So, perhaps the others have hung too long at the butchers. It's not a problem I've ever experienced before, so I will accelerate that process.
I realise too that I've a cousin who supervises meat packing facilities, so I'm going to pick her brains.

Coulda done with you being around still eh? Chris King RIP.
 
South West Stalkers said:
Does it happen on particular cuts or generally in all your packs?
Click to expand...
@South West Stalkers - it was most obvious on diced (butcher leaves the fascia on, and it shows here, though personally, I don't) and on any haunches with fascia left on. Any cut that leaches blood (all), the blood also turns.
One thing I've not reviewed is the specific age of the beasts (I believe some of the oxy/haemo-globin contents increase with age), but the range would be 1-4y/o.
It's not something I've noted previously, in previous years I shot the same qty (~35), but most went "in-skin" to local restaurants, so three obvious variables are
a) the qty I'm seeing butchered
b) the addition of a butcher to the chain
c) new commercial vac packer (+ pads + trays)

Update: @csl My in-the-trade cousin also recommended the MAP system, but it's probably not viable for me/most of us on here.... so if no-one else one here has noted these issues in their conventional commercial pressure vac-packing... then I'm doing something wrong.
 
geoffw said:
Collected two from the butcher this morning, now in the chiller at 1C. Vacuum packing later- will revert.
Click to expand...

Might be nothing but you mentioned the small fallow calf that you kept in your own chiller, you then butchered and packed it yourself and it did not suffer the problem.
All the other beasts were hung at the Butchers, is something amiss there?
Just a thought.

Willowbank.
 
geoffw said:
Thank you @South West Stalkers, good to know re the trays and pads.

One question- do you vacuum pack to rock hard?
I ask based on some reading @willie_gunn kindly sent me "The fact that the meat doesn't change colour makes me wonder whether you have the vacuum set too strong. I had a quick look at this link, which speaks about myoglobin (what gives meat its red colour). It was this sentence that tweaked my interest: "The use of a plastic wrap that allows oxygen to pass through it helps ensure that the cut meats will retain this bright red color". The ziploc bag [what I previously used] is not airtight, so the oxygen will still get through, whereas a strong vacuum will remove all oxygen and I wonder if that prevents the formation of myoglobin? Just a guess, and I am in no way a scientist!"

I'm pretty confident it's this/a chemical reaction rather than microbial because it's instantaneously evident and on the face of fresh slices, even though it seems somewhat counter-intuitive that this could be due to the absence of oxygen!

Mine's a mouth sealer rather than a sucking tube, but thank you for the suggestion.
Click to expand...
Sounds like there may be some PH reaction between the venison and the surface of the vacuum pouches you are using, it's not unknown for pouches to be incorrectly coated, though of course they are generally well- and properly made; have you tried using a different supply of pouches?

In the case of a chamber vacuum machine and using appropriate pouches for this type of unit, you will still get discolouration, albeit only usually after ten days or so, and then usually only with products containing either bone, eg shanks, osso bucco, etc, or possibly a layer of connective tissue; you can of course get discolouration and gasification if packing mince and keeping it too long or in marginal temperature limits, which I think is caused over time by the vastly increased surface area (the minced/ground meat) being exposed to air and all that is in it prior to the vac/sealing process; as you say, after the pack is opened to the air again, any gases formed dissipate and the colour of the venison perks up again. Inert gas flushing the packs is possible with certain types of machine, but given the guidelines for UBD it shouldn't be necessary for venison.

I don't think it likely that it could be the vacuum 'intensity', as the chamber machines are almost always fitted with much stronger pumps than the external type machines, and typically seal to considerably lower vacuum pressure level.

Sorry I can't be more specific, but I hope you get to the bottom of it.
 
Update:
We packed two beasts on Wednesday night and did not experience the blue/green issue, using a variety of methods
a) vac pack only
b) vac pack + blood pads
c) vac pack + blood pads + styrofoam tray
d) vac pack + blood pads + foil backed card

On the one hand, that's good, but on the other hand, I am unable to replicate, nor identify, the issue. I may have to write it down to experience.

I've invested in some digital thermal recorders to increase the frequency of the data reads (thanks @willie_gunn ) , but it's a grown up commercial chiller and was only serviced last year, so it's not the obvious issue.
I'll reduce the hanging times where possible, although 9 days at 7C/24hrs and then 3C should also not be the problem (and they smelt/tasted light/perfect, not "gamey"). Yes, I removed and hung them out of the chiller while I cleaned it, but that's a five minute operation at an ambient of 10-11C, so well within every guideline. The c/s don't touch the walls either.

Thank you all for your wisdom and thoughts, I do appreciate it-
Have you changed your bleeding out regime or shot placement?
That's an interesting one for sure, I consulted the records, but no, I've not changed shot placement @sh1kar - it's high heart or hilar for me and these are all suspended bleed/gralloch from branch or vehicle deer hoist.

@willowbank yes, I wondered the same, the butcher handling being a variable- perhaps it was not even something "amiss", but rather something "different" from my norm, that I may never identify.
I've done 8 or so beasts subsequently (myself and through the butcher), but it's not been replicated.

@Freeforester Thank you for all the detailed advice in your reply.
Yes, pH/coating could be it. I have used Nisbets rolls (ie should be first rate) consistently without previous (or subsequent) issues.
This most recent time round (Wednesday night) I opted for Nibet's pre-formed bags and had no issue- though that probably proves little.

Noted for future reference your advice re products containing either bone or possibly a layer of connective tissue. Are you including "fascia" in the definition of affected "connective tissue" please?
Mince- yes, I freeze this quickly or give it a short UBD (if chilling only) to avoid this gasing/tinge- consumer perception is everything after all!

Thank you all, still stumped, but cheered by all the helpful advice.
 
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