Transcript Describing hop in beer - Hop Products Australia

Introduction
Hop Research: Understanding the contribution of hop
to beer flavour – our search for the Holy Grail
Why “Flavour”
Describing
Flavour
Presented by Dr Simon Whittock
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
Experimental
infrastructure
Metabolomics
This research was supported under
Australian Research Council's Linkage
Projects funding scheme
(LP140100160)."
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Conclusion
Introduction
Flavour:
the moment when what
we put in our mouths and
what we smell converge
(Simran Sethi)
We describe our hops as
having distinctive FLAVOUR
because:
i) we wanted to make the
point that hop aroma
should be subordinate to
BEER FLAVOUR; and
ii) we deliberately broke
with the typical meaning
of “aroma hop”
Why “Flavour”
Describing
Flavour
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
Experimental
infrastructure
Metabolomics
Conclusion
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Introduction
1.
2.
3.
4.
5.
6.
7.
8.
citrus
solvents
spices
floral
fruit
herbal
milk/nuts/grain
sulphur
Description of Flavour
Why “Flavour”
Odour Descriptors:
Castro, J.B., Ramanathan, A., and Chennubhotla, C.S. (2013). Categorical
Dimensions of Human Odor Descriptor Space Revealed by Non-Negative
Matrix Factorization. PLoS ONE 8, e73289.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0073289
Odour Maps:
Zarzo, M., and Stanton, D.T. (2009). Understanding the underlying dimensions
in perfumers’ odor perception space as a basis for developing meaningful odor
maps. Attention, Perception, & Psychophysics 71, 225-247.
http://link.springer.com/article/10.3758/APP.71.2.225
Flavour Networks:
Ahn, Y.-Y., Ahnert, S.E., Bagrow, J.P., and Barabási, A.-L. (2011). Flavor
network and the principles of food pairing. Scientific Reports 1, 196.
http://www.nature.com/articles/srep00196
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Describing hop in beer:
Sensory training for hops and hop intensive beers – let’s speak one language
Alicia Munoz, Barth Haas, United Kingdom, 12th Trends in Brewing
Conference’, KU Leuven, Ghent, Belgium, 3-7 April 2016.
https://view.publitas.com/ku-leuven/tib-2016_brochure/page/10-NaN
The Language of Hops: How to assess Hop Flavour in Hops and Beer
Georg Drexler, Christina Schönberger, Elisabeth Wiesen, Mark Zunkel,
Sebastian Hinz, Alicia Muñoz Insa, World Brewing Congress, August 13-17,
2016, Denver, CO 80202, U.S.A.
http://www.worldbrewingcongress.org/Pages/default.aspx
Describing
Flavour
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
Experimental
infrastructure
Metabolomics
Conclusion
Considerable effort required to understand which
compounds are responsible for perception of FLAVOUR
1. Isolation of the volatile compounds
•
Distillation, Gas or solvent extraction, headspace analysis
2. Sensory relevance
•
Aroma Extract Dilution Analysis (AEDA) - Headspace Gas Chromatography/Olfactometry
3. Concentration and identification
•
Focus on aroma substances which have higher flavour dilution factors from AEDA GC/O
•
Enrichment, determination of chemical structure, enantioselective analysis
•
Isotopic dilution analysis (deuterium or carbon-13), standards for extraction, detection and
quantification.
Concentration in food divided by the odor or taste threshold (water, oil, or other substrate)
5. Simulation of the aroma on the basis of the analytical results
•
Recreate the flavour/aroma profile using mixtures of individual compounds.
6. Omission experiments
•
Accounts for additive or antagonistic effects
Why “Flavour”
Describing
Flavour
Key Literature
Food Chemistry Authors: H-D Belitz, Werner Grosch, & Peter
Schieberle. Published by Springer in 2009,
http://www.springer.com/us/book/9783540699330
Dunkel, A., Steinhaus, M., Kotthoff, M., Nowak, B., Krautwurst,
D., Schieberle, P., and Hofmann, T. (2014). Nature’s Chemical
Signatures in Human Olfaction: A Foodborne Perspective for
Future Biotechnology. Angewandte Chemie International Edition
53, 7124-7143.
http://onlinelibrary.wiley.com/doi/10.1002/anie.201309508/abstra
ct
4. Quantification and calculation of aroma values
•
Introduction
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
many volatile compounds
Our approach
few aroma active compounds
Experimental
infrastructure
10000:350
Metabolomics
.
Conclusion
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Hop derived compound classes with FLAVOUR properties in beer
Introduction
Why “Flavour”
α-acids
polyphenols
sesquiterpenes
monoterpenoids
monoterpenes
thiols
~350 g/mol
~354 g/mol
~204 g/mol
~154 g/mol
~136 g/mol
~132 g/mol
bitterness
bitterness
perception?
mouthfeel
herbal and spicy
characters
citrus/floral
floral/resin
specific fruits
garlic/sulphur
isoxanthohumol
humulenol II;
humulene
epoxide III;
caryophylla4(12),8(13)- diene-5ol;
14-hydroxy-ßcaryophyllene; 3Zcaryophylla-3,8(13)diene-5α-ol; and 3Zcaryophylla- 3,8(13)diene-5ß-ol
Iso-alpha acids
humulinones
Iso-α-acids.
Humulinones develop
during oxidation of hops
and can be absorbed
during dry hopping
Taniguchi et al. (2013). J
Agric Food Chem 61, 31213130.
(R)-linalool;
geraniol, βcitronellol
myrcene
4-mercapto-4methyl2-pentanone (4MMP)
Describing
Flavour
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
Isomerised during
wort boiling
Epoxides and
diepoxides of
humulene and
caryophyllene form
during oxidation,
derivatives formed
during wort boiling
Glycosides
Yeast
biotransform
ation. (S)linalool from
myrcene
Direct
absorption
in beer
when late
or dry
hopping
Thought to be
derived from
conjugated amino
acid precursors in
presence of yeast
Oladokun et al. (2016).
Food Chemistry 205,
212-220.
Van Opstaele et al.
(2013). J Agric Food
Chem 61, 1055510564.
Takoi et al.
(2011). J Inst
Brew 116,
251-260.
Castro et al.
(2015) J Inst
Brew 121,
197-203.
Ochiai et al. (2015) J
Agric Food Chem 63,
6698-6706.
Experimental
infrastructure
Metabolomics
Conclusion
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Who is publishing in the field of Hop FLAVOUR
Introduction
Why “Flavour”
Odourant Polyfunctional Thiols from hop
(specific fruit notes)
Conferences:
Trends in Brewing
Young Scientist’s Symposium
Sonia Collin, Jacques Gros (KU Leuven, Belgium)
Toru Kishimoto (Asahi, Japan)
Oxygenation products of sesquiterpenes
(spicy characters)
Filip Van Opstaele, Tatiana Praet (KU Leuven, Belgium)
Describing
Flavour
World Brewing Congress (incorporates
ASBC and MBAA meetings in 2016)
ISHS-Humulus
Identification
of compounds
Hop Derived
compounds
Who &
where?
EBC Congress
Still to
understand?
Monoterpenes and monoterpenoids
Our approach
Martin Steinhaus (German Research Centre for Food
Chemistry | Leibniz Institut, Freising, Germany)
Experimental
infrastructure
Kiyoshi Takoi (Sapporo Breweries Ltd, Japan)
Hop utilisation and quality
Metabolomics
Tom Shellhammer (Oregon State University, USA)
Conclusion
IV International Humulus Symposium, Yakima, Washington 2015
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Still a lot to understand..
Brewery factors:
• Timing of hop addition
• Temperature and duration of exposure
• Interactions with yeast
• Interactions with filtration or pasteurisation
• Interactions with CO2 or alcohol
Hop factors:
• Mode of transfer to beer (biotransformation, glycosides,
oxidative or enzymatic changes)
• Optimisation of growing, harvesting and processing
• Variation between or among cultivars
• Biosynthesis and genetic control
Introduction
Why “Flavour”
Describing
Flavour
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
Experimental
infrastructure
Metabolomics
Conclusion
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
HPA’s approach to Research
Introduction
Why “Flavour”
Describing
Flavour
Identification
of compounds
Hop Derived
compounds
Who &
where?
Vertically integrated company conducting hop breeding, propagation and deployment, cultivation, processing,
sales and marketing
Currently ~95% of our acreage is planted to our own proprietary varieties developed in a dedicated plant breeding
program.
Critical for HPA to be able to continue to offer:
i) hop products with physical, chemical and quality characteristics desired by brewers; and
Still to
understand?
Our approach
Experimental
infrastructure
Metabolomics
ii) novel varieties with truly distinctive character
Conclusion
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Variation, biosynthesis and genetic control
Introduction
Why “Flavour”
Describing
Flavour
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
Experimental
infrastructure
Metabolomics
Conclusion
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Genotyping, linkage map construction,
quantitative trait loci identification
Metabolomics….
Introduction
Why “Flavour”
Headspace GC-MS, female and male plants, two sites
Describing
Flavour
Sample, dry, store
hops and male
flowers
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
myrcene
linalool
caryophyllene
humulene
Experimental
infrastructure
Metabolomics
High throughput,
small scale
fermentation
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Conclusion
Headspace GC-MS of volatiles from experimental fermentation
Putting it all together..
Introduction
Why “Flavour”
•
•
•
•
•
More precise selection of parents for
breeding
Efficient selection of superior varieties
Improve cultivation
Understand biosynthesis and
accumulation of key/marker
compounds
Optimise timing of harvest, kilning,
handling, processing and packaging
Describing
Flavour
Identification
of compounds
Hop Derived
compounds
Who &
where?
Still to
understand?
Our approach
Experimental
infrastructure
Maximise opportunity for brewers
to make great beer!
Presentation at the Australian Craft Brewers Conference, Brisbane, 20 July 2016.
Metabolomics
Conclusion