Thursday, 19 September 2013

The Aroxa challenge comes to Plumpton College

The academic year at Plumpton College has started in earnest today. Our second year wine students have come back from their summer activities to enrol for the new year. Besides enrolling they are doing a short course on 'Safe winery practices' to ensure they can successfully work in the winery. The first year wine students are already enrolled and learning the rules and regulation of higher education, so they can start classes next week.

This year I decided to organise a little competition for the wine students to provide a break from their lessons, to benchmark where they are and inspire them to improve over the coming year. To make this happen we got  technical assistance from Aroxa based in Leatherhead, Surrey.  Aroxa was founded by Dr Bill Simpson of Cara technology (world leader in Brewing science), as a company to supply flavour standards to the Beer industry.  

Flavour standards for those not familiar with them, are high purity odour/flavour compounds, bound to a complexing agent and delivered at the correct dose rate into sample beverage. They allow industry personal to train themselves on the sensory impact of specific compounds with minimal fuss and at dosage rate found in the target beverage.  The can range from ng to mg levels depending on specific odourants.
Capsules containg 22.5 micrograms of Guaiacol for adding to wine  (Aroxa)
These standards are widely used in the beer industry for tasting panel training and validation. They are also used in the cider & water industries and more recently the wine industry.

So today Lee Hinds who is Aroxa's development chemist, came to Plumpton College with a collection of 10 key wine flavours:
  • Vanillin - “Vanilla, like ice cream or custard”
  • Guiaicol - “Smoky, like smoked fish or cheese
  • β Ionone -“Violets, like Turkish delight”
  • β Damescenone - “Damascenone, floral with undertone of red fruits”
  • Isoamyl acetate -“Isoamyl acetate, like bananas or pear drops”
  • 2,3 Butanedione - “Diacetyl, like butter, or butter popcorn”
  • 2 Isobutyl 3 Methoxypyrazine - “Earthy, like green pepper”
  • cis 3 Hexenol - “Freshly cut grass, like hedge cuttings”
  • Lactone - "Like coconut"               
  • Gereniol - “Geraniol, like rose petals”
These flavours were the basis of the 'Aroxa Challange' that we conducted with our wine business and wine production students.

Lee Hinds discussing flavour compounds
First up Lee, gave a standard dose to the students in water and explained the importance of that compound to wine.  Once the students had familarised themselves with the compounds they were presented with 10 blind samples at half strength in a randomised order.  For the student correctly identifying all 10 flavour compounds, they were then challenged to identify flavour mixtures or quarter strength standards until the heat winners we found.

Many interesting things came out from these tastings, firstly many students found out about any personal specific anomsia (inability to detect single smells)  they may have.  Personally I discovered I am odour blind to β Ionone, though I am not alone in this as it is a very common anosmia (approx 50% of people) as shown in this 2006 study by Plotto, Barnes and Goodner. Some student also discovered that while the compounds are detectable, they present a different aroma note to those which others find, a example of this includes lactone presenting as dill/hamburger pickle notes not just the classic coconut aroma.  Finally we collected some simple data on intensity as a way of potentially refining the dose rates in the future.

The students and staff enjoyed the challenge immensely, and some got quite competitive

Sarah Redpath heat 1 winner
Ian Holloway, heat 2 winner

In the end the three heat winners Sarah Redpath, Ian Holloway and Rory Loftus (not pictured) walked away with the glory and respect of their peers as well as a bottle of wine courtesy of Aroxa team.  

Next year we shall try again, to see how the 2013 student have improved and allow our 2014 students to benchmark their initial tasting skills.

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