Abstract
(1) Background: Solid phase microextraction (SPME)-Arrow is a new extraction technology recently employed in the analysis of volatiles in food materials. Grape volatile organic compounds (VOC) have a crucial role in the winemaking industry due to their sensory characteristics of wine.; (2) Methods: Box–Behnken experimental design and response surface methodology were used to optimise SPME-Arrow conditions (extraction temperature, incubation time, exposure time, desorption time). Analyzed VOCs were free VOCs directly from grape skins and bound VOCs released from grape skins by acid hydrolysis.; (3) Results: The most significant factors were extraction temperature and exposure time for both free and bound VOCs. For both factors, an increase in their values positively affected the extraction efficiency for almost all classes of VOCs. For free VOCs, the optimum extraction conditions are: extraction temperature 60 °C, incubation time 20 min, exposure time 49 min, and desorption time 7 min, while for the bound VOCs are: extraction temperature 60 °C, incubation time 20 min, exposure time 60 min, desorption time 7 min.; (4) Conclusions: Application of the optimized method provides a powerful tool in the analysis of major classes of volatile organic compounds from grape skins, which can be applied to a large number of samples.
Highlights
Grapevine is one of the most important horticultural crops in the world, mainly used for wine production
In a case of the compounds with the small value of the distribution coefficient between coating and the Molecules 2021, 26, 7409 sample, the amount of analyte extracted is almost independent upon sample weight [19]
The results obtained in this study indicate that the most significant factors were extraction temperature (p-values for almost all group of analyzed volatile organic compounds (VOC) are lower than 0.0001) and exposure time (p-values for all group of analyzed VOCs are in the range from 0.0002 up to 0.0412) (Table 1)
Summary
Grapevine is one of the most important horticultural crops in the world, mainly used for wine production. The aromatic profile of grapes is very complex and includes a large number of different volatile organic compounds (VOCs). The products from a chemical acid hydrolysis may reflect more closely the natural states of free aromatic compounds in grapes and wine because wine is produced under acidic conditions [4]. This was shown by Loscos, et al [6], who compared enzymatic and acid hydrolysis. Even though the enzymatic hydrolysis showed higher efficiency, the levels of most VOCs found were poorly correlated with those found after alcoholic fermentation. The transformations taking place during fermentation include relevant chemical rearrangements in acid media that are better predicted by acid hydrolysis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
