Malt Derived Proteins LTP1, Z4, and Z7 in Beer Foam Development and

RetentionKyle Breitinger

Mentor: Charles CoughlinModerator: Casey Zender

Bader, 2014

Frothy collection of bubbles formed at the top

of beer Also called beer head or froth Formed by interactions between proteins and

gas

What is beer foam?

How is it made?

Okayama University discovered the three major proteins that contribute to beer foam: Lipid Transfer Protein 1 (LTP1) Z4 Z7

Hydrophobic due to alpha-helical folding

Blasco, 2011

U of U 2016

• Proteins surround gas bubble and ride up to the surface

• Creates bubble lattice on top of beer

Bech, 1995

Where do these

proteins come from?

LTP1 is the main

contributing factor for beer foam production Globular form in raw barley Becomes denatured during

“mashing” Denatured form is active

Z-proteins are foam stabilizing Major factors in foam retention

How do these proteins affect beer foam?

Temperature (Foam +/-)

1. Mashing 2. Serving

Due to CO2 solubility Detergents/lipids (Foam -) ABV (alcohol by volume)

(Foam -) Etching in the glass (Foam

+/-) Nucleation sites

What can affect beer foam?

Why do we want foam?

Releases odor compounds (aromatic esters) to the surface contribute to smell and taste of beer

Acts as a Trigeminal sensation Due to Cranial Nerve IV (much like spicy

foods and mint)

Foam means there is still carbonation in the beer! When flat, beer will produce little to no

foam because of two reasons:1. No gas means no foam2. There is a limited supply of proteins

It Makes for a great Mustache!

Theawesomer.com

Foam measuring machine Mechanical sensor that follows the beer down the

glass as the foam decays This measures:

How fast the foam deteriorates How much foam

How do you quantify beer foam?

Onshi and Proudlove, Japan: Looking to see what was in beer

foam Used nitrogen to create foam The foam was then separated into two fractions through

column chromatography1. High molecular weights 2. Low molecular weights

How did we find out about these proteins?

Kai, 2013

The high molecular weight

fraction: contained mostly carbohydrates 10 percent protein (these proteins were

the two Z-proteins (Z4 and Z7))

The small molecular weight fraction: Mostly proteins

later found to be LTP1

What were their findings?

LTP1 molecular structure

Bech, 1995

Z- protein. EMBL 2015

Van Nierop et al, South Africa Two South African breweries

(Brewery A and B) Asked to brew the same exact

beers using the same exact raw materials

They were given identical sampling time intervals

Wanted to know: Any differences in the way they

make beer Would this affect beer foam

production?

How Denatured LTP1 Was Found To Create Beer

Foam

Samuel Adams, 2014

Brewery B’s beer contained more foam and higher

levels of LTP1 (through ELISA) than Brewery A’s beer Brewery A was at an attitude of ~200 meters above

sea level Brewery B was at an altitude of ~1800 meters above

sea level Why does altitude matter?

Brewery B is at a higher altitude which means they are brewing at lower atmospheric pressure compared to Brewery A Brewery A wort boiling ~ 102 Degree Celsius Brewery B wort Boiling ~ 96 Degrees Celsius

Results of South African Brewing Experiment

Results of South African brewing experiment

(continued…)

Table 1 LTP1 levels measured via ELISA over the brewing process at breweries A and B (Van Nierop et al, 2004)

Brewery B had higher LTP1 levels due to

lower temperatures and less denaturation

Brewery A had lower LTP1 levels due to proteins being denatured to a greater extent to a non-functional conformation

LTP1 was more effective at binding free fatty acids when it is not fully denatured

Results of South African brewing experiment

(continued…)

Results of South African brewing experiment

(continued…)

Brewery B

Brewery AVan Nierop et al, 2004

YES! Growing barley in drier climates helps produce more

LTP1 in the barley thus creating more beer foam when brewing

Some scientists have taken pure mixtures of denatured LTP1 and tried to introduce it after fermentation. This created beer foam that was very unstable and did not last long

German scientists have spliced the gene encoding for LTP1 production into yeast cells. These cells then create LTP1 during fermentation increasing the concentration and causing for more beer foam

Have we tried to brew with more LTP1?

Foam Mug Creates bubbles that induce foaming

Etched glasses (Guinness created a special glass) Creates more nucleation sites = More foam

We have the devices to create more foam!

Guinness, 2010

1. LTP1 is the major protein involved in foam production2. Z4 and Z7 maintain beer foam stability3. Without these proteins beer would not be as

enjoyable as it is with an aromatic full bodied beer head

Conclusions

Agric, James. "A Heady Discovery for Beer Fans: The First Gene for Beer Foam

Could Improve Froth." Journal of Agriculture and Food Chemistry 60.43 (2012): 10796-0807. Phys.org. Web. 19 Dec. 2015.

Allain, Rhett. "Modeling the Head of a Beer." Wired.com. Conde Nast Digital, 25 Jan. 2009. Web.

"Beer Head Retention-| Brewer's Friend." Brewers Friend RSS. 19 Dec. 2009. Web.

"Carbonation - What You Need to Know To Help You Serve Draft Beer." Draft Beer Made Easy. 2009. Web.

Christensen, Emma. "Good Foam, Bad Foam: What's the Deal with Beer Foam? - Beer Sessions." Thekitchen.com. 2012. Web.

Colby, Chris A. "Getting Good Beer Foam: Techniques." Getting Good Beer Foam: Techniques. Brew Magazine, 5 Dec. 2005. Web.

Evans, D.e., and J. Hejgaard. "The Impact of Malt Derived Proteins on Beer Foam Quality. Part I. The Effect of Germination and Kilning on the Level of Protein Z4, Protein Z7 and LTP1." Journal of the Institute of Brewing 105.3 (1999): 159- 70. Web.

Work Cited

Gerritson, Vivienne B. "One Beer Please." Protein Spotlight The Full. SIB Swiss Institute of

Bioinformatics, 01 May 2004. Web. Halford, Bethany. "Four Tips for Getting the Best Beer Foam." Newscripts. Chemical and

Engineering News, 03 May 2013. Web. Karl, Siebert J. "Recent Discoveries in Beer Foam." Journal of the American Society of

Brewing Chemists ASBC 72.2 (2014): 79-87. Web. "Kilning | Beverage Production." Encyclopedia Britannica Online. Encyclopedia

Britannica. Web.   Lees, Michael A., Peter A. Rodgers, Duncan B. Campbell, Michael A. Pecar, and David C.

Shudarmana. "Intelligent Systems for the Brewery Based on Real-Time Measurement of Biological Parameters." Australian Barley Technical Symposium 53.1 (1999): 313-16. The Regional Institute.

"Plant Lipid Transfer Proteins." Wikipedia. Wikimedia Foundation, 02 Dec. 2015. Web. Rudin, A. D. "Measurement Of The Foam Stability Of Beers." Journal of the Institute of

Brewing 63.6 (1957): 506-09. Veneri, Gianluca, Gianni Zoccatelli, Silvia Mosconi, Chiara Dalla Pellegrina, Roberto

Chignola, and Corrado Rizzi. "A Rapid Method for the Recovery, Quantification and Electrophoretic Analysis of Proteins from Beer." Journal of the Institute of Brewing 112.1 (2006): 25-27.

Work Cited Cont…

Bader, Heinz Peter. Foam in Beer. 2014. Corbis, Seattle,

Washington.   Bech, M. L. Barley LTP1 Molecule. 1995. European Brewery

Congress, Brussels. Blasco, Lucia. Foam Structure. 2011. Microbid International,

Barcelona, Spain. Santilli, Laura. Gene for Beer Foam. 2005. Fotolia, New York.

Kai. Yeast and O2. February 2, 2013. Braukaiser, Germany. Urie, Brendon. Guinness Mustache. 2011. Tumbler, Dublin,

Ireland.   The Mo-Gaurd. Theawesomer.com, California. Vesicle. University of Utah. 2016. LearnGenetics.com

Picture Citations

Professor Charles Coughlin Bold City Brewery Dr. Lentz Casey Zender Trevor Cheatham Beer

Special Thank You