Allergenic Egg White Proteins in Wine: New Methods Detect Measurable Amounts in Finished Wine

The practice of including warnings about possible food allergens on consumer goods is becoming more commonplace across the globe.  According to the Directive 2003/89/EC in the European Union, all foods that contain traces of a specific list of potential allergens must have a label indicating their presence.  There is similar legislation (in some form or another) in other countries as well, including Australia and the United States.  These labeling laws are placed on hold when the potential allergenic components are used in processes such as winemaking, since there doesn’t appear to be strong scientific data suggesting these allergens are present in the finished product after processing.

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One part of the winemaking process that has the potential to introduce allergens into wine is in the fining process.  The purpose of fining is to remove undesirable phenolic compounds while also reducing bitterness and astringency.  During fining, proteins are added to the wine (i.e. gelatin, milk casein, albumin from egg whites, etc) which then interact with polyphenols and form complexes, which can then be removed via a filtration step or other techniques.  These proteins, particularly eggs, can cause severe allergic reactions in some individuals (0.3% of the adult population), thereby making their presence in wine problematic.  Even with the filtration step, it is not guaranteed that all of the potential allergens will be removed. 

Red wine fining in particular, often employs the use of egg whites (either fresh or in freeze-dried powder form), with doses ranging from 5-15g of fining agent per hL of wine.  Current analytic methods, such as ELISA analysis, do not appear to be particularly sensitive to lower doses of egg white albumin used in the fining process.  Newer methods, such as mass spectrometry, may prove to be more accurate for detecting trace levels of allergens in wine, though the only work done on wine so far using mass spectrometry was using milk proteins and not egg whites.

The purpose of the study reviewed today was to detect egg white proteins in finished red wine using both immunoenzymatic and mass spectrometry techniques.  If either of these techniques is able to find traces of egg white proteins, then the appropriate label should be affixed to the wine in order to avoid any potentially serious allergic reactions by the consumer.

Methods

Egg whites preparations (Albuclar®) were commercially produced and supplied by Enologica Vason S.r.l. in Verona, Italy.

A 2009 vintage Merlot was the wine chosen for the experiment.  As a control, a commercially produced Amarone from a winery in the Valpolicella area in Verona, Italy was used.  This wine was treated commercially using the same Albuclar® egg white preparation as the experimental wine.

Egg white preparations were added to 500mL each of the experimental wines in concentrations of 5, 10, 15, 50, 150, 250, and 300g/hL.  The wine sample treated with 50g/hL of egg white preparation was fined with 50g/hL of bentonite and then filtered on 0.65m in order to test the ability of the absorbent to remove the egg white protein.

For protein detection, gel electrophoresis, dot blot, immunochemical analyses, liquid chromatography and mass spectrometry methods were employed.  For mass spectrometry, only wines with the 5 and 10g/hL doses of egg whites were analyzed.

Results

  •       Protein bands on the electrophoresis gel corresponded to the proteins found in egg whites, all of which are known to be allergenic proteins.
  •        For the immunochemical analysis, egg white proteins were only detected in wines treated with egg whites at doses of 50g/hL or higher.
  •       For the commercial wine supplied by the winery, no egg white proteins could be detected using the immunochemical techniques.
  •       Using mass spectrometry, egg white proteins were found in all of the experimental wines treated with Albuclar®, including the experimental wine treated with the lowest dose (5g/hL).
  •       Using mass spectrometry, egg white proteins were found in both white and red wines.

o   Specific proteins detected by mass spectrometry were ovalbumin, ovotransferrin, lysozyme, and ovomucin.

  •       The mass spectrometry results reveal that it is more sensitive and able to detect egg white proteins in wine where standard immunochemical techniques could not.
  •       Using mass spectrometry, egg white proteins were found in the wine that was treated with bentonite (comparable to the amount found in wines not treated with bentonite).

Conclusions

The results of this brief study indicate that the fining and filtration steps used in winemaking are unable to remove all remnants of egg white proteins from the final wine.  The results also show that standard immunochemical techniques that have been used in the past to determine egg white protein presence lack sensitivity and are inferior to newer techniques such as mass spectrometry.  With mass spectrometry, the scientists were able to find egg white protein in all wines, regardless of the original fining dosage. 

The authors claim they are the first to show that mass spectrometry (combined with liquid chromatography) to detect egg proteins in wines treated with some of the lowest dosages currently used in winemaking fining processes.  These results could have important consequences for the labeling wine with allergenic warnings, which could potentially prevent many adverse allergic reactions for those suffering from egg allergies.

Were you aware that finished wine still contains egg white proteins after processing?  Let me know what you think by commenting below!

Source:  Tolin, S., Pasini, G., Curioni, A., Arrigoni, G., Masi, A., Mainente, F., and Simonato, B. 2012. Mass spectrometry detection of egg proteins in red wines treated with egg white. Food Control 23: 87-94.

DOI: 10.1016.j.foodcont.2011.06.016
I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!

16 comments for “Allergenic Egg White Proteins in Wine: New Methods Detect Measurable Amounts in Finished Wine

  1. Richard Mansfield
    December 14, 2011 at 5:38 pm

    There is the question as to what level will trigger an allergic response in susceptible individuals. Before we jump on the added cost of labeling and confusing our customers, studies should be done as to what levels of allergens are acceptable. At a certain level, as analytical methods become ever more refined, we will find atomic levels of virtually all known substances everywhere. I presume we could probably find Ovalbumin in seawater if our methods were refined enough.

    According to my own MS-BS spec studies, there is a substantial portion of Jimmy Hoffa in all wines I've analyzed. Should we indicate this also? And if he is present, would that render such wines as unsuitable for Vegans and Vegetarians? Hummm….

  2. December 14, 2011 at 9:42 pm

    Great points, Richard! I don't happen to know off-hand what the allergic response levels are for those that are susceptible. I also haven't scoured the allergy research enough to know if these studies have been done yet or not. That is a great next step though, before more writing it simply slapped onto wine bottles.

    I find your Jimmy Hoffa results intriguing. However, my dog was left wondering why his mom suddenly busted out with laughter for no apparent reason 😉 I agree though, we should warn Vegans/Vegetarians about that 😉

  3. December 15, 2011 at 4:31 pm

    Does the study just look at egg whites, or any of other fining materials that are potential allergens? I agree with Richard, that finding a standard that causes a reaction is key, along with the method of measuring if you can meet that standard. With Canada's wine allergen label laws going into effect next summer, the topic it timely.

  4. December 15, 2011 at 6:26 pm

    Thanks for commenting, AllergyFreeT!

    This study was relatively short, and only included egg whites as the fining material. It'd be interesting to see a study looking at multiple sources of fining material with potential allergenic properties.

    Do the new Canadian label laws include listing potential allergens?

    Thank you again for commenting!

  5. Flying Scotsman
    December 15, 2011 at 10:48 pm

    Very interesting. Using the theory that traces of egg whites are found no matter what, I am making a leap to conclude that this would apply to all fining agents. I am very susceptual to any product from a cow and suffer considerable headaches as a result. I notice that with certain wines I too have the same effect, this is not caused by over consumption, the amount drunk is identical, two glasses in either case. I wonder if the the wines that cause me a problem contain dairy products?

  6. Patrick
    December 15, 2011 at 11:18 pm

    I’ve not heard of the egg allergy. How widespread is this problem?

    Furthermore, active proteins, like antigens and enzymes, require an unforgiving degree of specificity. One incorrect amino-acid in a precise sequence of several hundred renders the protein inactive. The inactivity is caused by a MINISCULE change in the molecule’s three-dimensional shape. Environmental factors – heat, pH, alcohol, tannin, osmotic pressure — can also change the shape enough to inactivate a protein. The environmental shock experienced by egg-albumin thrown into a red wine would dramatically alter its shape and certainly inactivate its antigenic properties.

    Conclusion: The ability to detect that a certain protein has been added doesn’t provide useful information about potential allergic reactions.

  7. December 15, 2011 at 11:23 pm

    I wouldn't be surprised if all fining agents could be found in traces in all wines. I can't imagine being able to remove every single bit of fining agent from every cubic inch of wine. That being said, as long as the amounts are high enough to illicit an allergic reaction, it's possible that could be affecting you in your wine consumption. Some winemakers will use casein, which is derived from milk, as a fining agent. I'd be curious to see if those wines that affect you the most use casein as their fining agents.

    Thanks for your comments!

  8. December 15, 2011 at 11:27 pm

    Thanks for reading/commenting, Patrick!

    I don't think egg allergies are too common. The paper cited 0.3% of the adult population as having egg allergies. That doesn't seem like a lot to me, however, I'm not an allergist, so I could very well be wrong about that.

    Great points about the winemaking process rendering the potential allergic agents inactive. I'd be curious to see some molecular data to see how the compounds change in this sort of situation.

    I agree with your comment that simply being able to detect the proteins in the wine doesn't actually give any useful information about potential allergic reactions. However, I think it's a step in the right direction. At least they know it's there, now perhaps the next set of experiments would involve looking at the molecular structure, and whether or not the amounts measured would even have an influence on individuals who are allergic to eggs.

    Great comments! Thank you!

  9. Charmion
    December 23, 2011 at 9:58 pm

    Re: the labeling law issue. I wish the govt. would refrain from issuing new, mostly ignored, overlapping, confusing label laws until they can show some actual harm that is specifically connected to a specific element and that element is identifiable and controllable. Otherwise, the govt. issuing more laws is "pin the tail on the donkey".

  10. DCS
    July 11, 2012 at 12:07 pm

    I think this is a load off bull. Rule of thumb is 1-4 egg whites /hl of wine. After the fining Bentonite has to be added to get the wine protein stable again. Thus removing a massive amount of the proteins again.
    0.3% of people world wide are affected, that's about 2100000 of which, lets say, 2 % drink wine so that's 42000 people (thumb suck). How many of these people have such severe allergy that they will be affected by the trace amounts in wine? 10 %? 4200 people?
    4200 people world-wide?!
    This howl thing is blown out of per portion. This is just another plan by the EU (Germany) to make money and try to curb wine imports to Europe to boost ailing local wine sales. The same thing happened to Natamycin in wine. Who holds the patent for the lab testing equipment and alternative products? EU companies. Ochratoxin A in wine is also again rearing its ugly head and soon Gelatine will also follow.
    It's a bad joke.

  11. Tom H.
    August 31, 2012 at 11:41 pm

    This is interesting. I am allergic to eggs and just became aware of egg white fining with red wines. One wine particularly causes me allergic symptoms and yes,I've learned since that they use egg white fining for Columbia Crest's Walter Clore red.

  12. September 4, 2012 at 4:21 pm

    Thanks for your comments, Tom!

    That's unfortunate that you're allergic to eggs! At least you've been able to identify why it is you were having allergic symptoms with some wine and now have the tools necessary to avoid it in the future (while still being able to enjoy other wines without egg white fining!).

  13. Lisa
    November 17, 2012 at 11:07 am

    This is some great information, thank you for the post. I recently was diagnosed with an egg allergy and have found that eggs are in many products I never realized before. When a friend mentioned that egg whites are used in the winemaking process, it was definitely an “ah ha!” moment. I always thought it must be something I ate that was causing my reaction, never dreaming it could have been my beloved red wine. Another observation has been that different wines give me a different level of reaction (I do not have a severe anaphylactic reaction, but itching and hives for up to 10 days), so I have been cautiously testing different wines and choosing those that don’t give me a reaction. Labeling would certainly help me choose a wine more easily, but for now, perhaps looking at vegan wines may be my solution.

  14. robyn lionetti
    June 15, 2013 at 11:15 pm

    I am severely allergic to eggs and have been since childhood
    Many years back i was getting severely ill after dinner serving red wine and couldn’t find an answer
    Well yes my answer was the wine of course
    I recently tried organic wines and have been able to tolerate them
    I am not a drinker but do enjoy a social drink
    Are there any manufacturers of red or white wine that can be 100% egg free?
    And of course i am all for labeling

    • Becca
      June 15, 2013 at 11:26 pm

      Hi Robin,

      I’m glad you were able to tolerate the organic wines! If you’re trying to avoid egg, you’ll need “vegan-friendly” wines. I stumbled across this site which may or may not help (i.e. I don’t know when it was last updated or if it’s completely accurate): http://www.barnivore.com/wine You might be able to try looking up wines on one of their apps (you can download free versions).

      The other thing to do would be to write/call the winery itself and ask if they clarified their wines with egg-white based compounds or something else. Don’t worry–there are a bunch of wines that don’t use egg, you just need to do a little research first! Labeling would be the easiest thing, but alas, we’re not quite there yet!

  15. Katja Virolainen
    December 15, 2013 at 4:22 am

    Thank you very very much for this article! I have a severe allergy for eggs and yesterday I got my first reaction from wine, didn’t know that could happen. I’ve never been much of a drinker, but I enjoy wines. For me to get this information and be aware is a lifesaver. Thank you!

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