â€śWine Technology of the Futureâ€ť is a series on The Academic Wino that features new inventions and patents that attempt to make your wine experience easier and more enjoyable, though sometimes we look at products that are already in existence but have not yet been verified as beneficial, accurate, or worthwhile.Â Previously on this series, weâ€™ve introduced the â€śself-aerating wine bottleâ€ť; the â€ścorkscrew with integral intelligent thermometerâ€ť; â€świne dispensing and preservation deviceâ€ť; â€śmulti-stream wine aerating deviceâ€ť; â€świne bag carrierâ€ť; and the â€śsystem and method for pairing food with wineâ€ť.
Todayâ€™s â€śWine Technology of the Futureâ€ť is actually not for consumers, but instead is for the winemaker.Â I recently read an article that compared the effectiveness of two different Lateral-Flow Devices for measuring the levels of Botrytis cinerea antigens in finished wines.Â As weâ€™ve talked about many times on The Academic Wino, and anyone who is a winemaker knows, Botrytis cinerea can be very devastating to table wines, though for those making late-harvest dessert wines, the presence of this fungus is actually highly desirable.Â Grey mold, with is a term frequently associated withBotrytis cinerea infections in grapes and other produce, can result in a finished table wine with off-flavors and aromas, which can also lead to significant economic losses due to damaged or destroyed crops.Â On the other hand, in late-harvest dessert wines, the presence of Botrytis cinerea is actually desired, since this â€śnoble rotâ€ť is partially responsible for the desired flavors and aromas of these finished dessert wines.
Lateral-flow devices (LFDs) have been used in other systems to detect and analyze fungal antigens, and so was thought that perhaps they could be used to detect levels of Botrytis antigens in finished wines, which could then been correlated to the levels of off- or desired flavors and aromas of the wine.Â In terms of application, LFDs are apparently very easy to use, and are very fast, taking only 5-15 minutes and easily used by untrained workers in any work space (no laboratory required).
The two LFD systems that one study compared were produced by the companies EnviroLogix (ME) and Forsite Pocket Diagnostics (NY).Â Both use very similar mechanisms, mainly through recognition of the Botrytis monoclonal antibody, BC-12.CA4, an antibody which is not degraded during the fermentation process.Â In technical terms, these LFD systems function mechanistically similar to an ELISA assay, or sandwich assay.Â In lay terms, what happens is this:
1)Â Â Â Â Â You have a wine that may contain the Botrytis antigen if it had been infected in the vineyard prior to winemaking.
2)Â Â Â Â Â You have this little LFD analyzer that contains the Botrytis antibody that recognizes (i.e. sticks to) the Botrytis antigen like a bug on sticky fly paper (itâ€™s not coming offâ€¦.).Â Attached to this antibody is a colored dye that will show up under specific light conditions.
3)Â Â Â Â Â Take a sample of your wine and insert it into your LFD system and it moves through via capillary action (i.e. like the drawing up of liquid through a tiny tube or through the grains of paper).
4)Â Â Â Â Â The more Botrytis antigen that is present in your wine sample, the more of it will stick to the Botrytis antibody in the LFD system. Since the antibody was also attached to a colored dye, the more antigen that is present in the wine sample, the brighter the color will be, which can then be correlated to a concentration of Botrytis in the wine based on known standards.
I realize thatâ€™s a really rough description, but itâ€™s basically the idea.Â If you need further clarification, please ask!
Both LFD systems from EnviroLogix and Forsite Pocket Diagnostics work very similarly, though where they differ is in where and when the Botrytis antigen is stuck to the Botrytis antibody in the system.
To compare each of the LFD systems for Botrytis detection in finished wines, one study examined 36 red table wines, 32 white table wines, and 27 dessert wines
Results showed that the analysis from both systems were well correlated with one another for table wines, indicating that one product did not appear to be drastically different than other in terms of its calculation of Botrytis in the sample wines.Â For dessert wines, the intensity of the Botrytis signal was greater in the Forsite Pocket Diagnostics LFD system than the EnviroLogix LFD system, however, these values were still well correlated with one another, indicating that back-calculating to total Botrytis concentrations in the finished wine is similar for both products, though the equations used to get these values would be slightly different depending upon which product one was using.
Which Device Should I Get?
If youâ€™re a winemaker who frequently deals with Botrytis cinerea infections, or youâ€™d like a way to correlate the levels of Botrytis cinerea antigens with the flavors and aromas of a wine, this technical study indicates that you can feel confident using either system: the EnviroLogix LFD or the Forsite Pocket Diagnostics LFD.Â The study also indicates that while both systems are easy to use (and reliable), the Forsite system is more designed to be used in the field, as it is more robust and encased in plastic (though note: because of this, itâ€™s more expensive).
These types of lateral-flow devices could be very useful for comparing the levels of Botrytis antigens to the flavor and aromas of the wine for both table and dessert wines, and as the authors of this study suggested, it could also be used for comparing Botrytis antigen levels in sparkling wine to the formation and retention of the tiny bubbles in the wine.Â Since
concentrations of Botrytis antigen do not change during fermentation, another application of this system would be to test antigen levels early on in the fermentation process, thereby allowing the winemaker to take necessary action to help combat the negative flavors and aromas associated with Botrytis cinerea infection, or in the case of dessert wines, to help coax out those desired flavors.
Have any of you tried LFDs in measuring Botrytis levels in your wine?Â Would you use these types of devices in your winery?Â Why or why not?Â Please feel free to leave your comments, questions, or what have you!
Source: Dewey, F.M., Steel, C.C., and Gurr, S.J. 2013. Lateral-Flow Devices to Rapidly Determine Levels of Stable Botrytis Antigens in Table and Dessert Wines. American Journal of Enology and Viticulture 64(2): 291-295.