Roland Exam Questions

Question 1

ROLAND
1. Knowledge about carotenoids:
a. Describe the chemical structure of carotenoids and linked sub-families. (2 points)
b. What are the main carotenoids in grapes? (1 point)
c. What are the main biosynthesis steps of carotenoids in planta? (1 point)
d. What are the main families of C13-norisoprenoids and the characteristic molecules? (2 points)
e. What is the impact of viticultural practices on C13-norisoprenoids? (4 points)

Question 2

ROLAND
Describe the different families of wine aromas during the winemaking process, the formation pathway (ie chemical or enzymatical) and cite at least one example of aroma compound for each family. (10 points)

Question 3

ROLAND
1. Knowledge about thiol precursors:
a. Describe the different families of thiol precursors in grapes.
b. What is the influence of viticultural practices on thiol precursors?
c. What is the cleavage mechanism of thiol precursors into corresponding thiols and describe the key parameters influencing their release?

Question 4

ROLAND
1. General definitions:
a. What is an aroma precursor? (2 points)
b. What is the definition of the perception threshold of an aroma compound?

Question 5

ROLAND
1. Knowledge on barrel ageing: (5 points)
a. What are the main constituents of oak heartwood that are responsible for aroma release? (2/5)
b. What are the main parameters that modify the extraction of oak aromas? Explain. (2/5)
c. What is the compound responsible for coffee notes during ageing? Explain the formation mechanism. (2/5)