University of Agronomic Sciences and Veterinary Medicine of Bucharest Faculty of Horticulture International Student Symposium “Hortus Academicus” March 29, 2019, Bucharest, Romania “THE EFFECT OF FAST MATURATION OF WINE DISTILLATE IN THE PRESENCE OF OAK CHIPS, ON COLOR PARAMETERS AND PHENOL EXTRACTION “ Author: BSc student Marius Alexandru STAN Coordinator Professors: Lecturer PhD George Adrian COJOCARU Professor PhD Arina Oana ANTOCE International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

INTRODUCTION With an increasing demand of distilled alcohol beverages, fast solutions must appear. One of them is using oak chips. The raw distillate dramatically change during maturation accordingly to the oak origin and the degree of thermal degradation of lignin during the toasting process. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

MATERIALS AND METHODS In order to obtain the product to be subjected to analysis, a volume of 100 liters of white wine, based on Feteasca Alba and Riesling Italian varieties, was double distilled in a traditional pot still. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

MATERIALS AND METHODS Alcoholic concentration of 64.2% vol. Fast maturation with 3 g/l oak chips of different types and different concentrations of oxygen Temperature of 27°C, for two months. table 1. Table 1.Types of oak chips and level of oxygen exposure International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

MATERIALS AND METHODS French, Medium toast American, Medium toast French, Heavy toast American, Heavy toast International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania International Student Symposium "Hortus Academicus“ April 27, 2018 - Bucharest, Romania

Spectrophotometric analysis MATERIALS AND METHODS Wine distillate Oak chips Spectrophotometric analysis Results 27°

MATERIALS AND METHODS An UV-VIS spectrophotometer Analytik Jena AG Specord 250 was used for colour and total polyphenol analyses. The colour intensity (OD at 420 nm) was measured in glass cuvettes of 10 mm optical thickness. The total polyphenol index (OD 280 nm) was measured following a dilution with water at 10% in a quartz cuvettes of 10 mm optical thickness. The TPI results were multiplied by 10. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

RESULTS AND DISCUSSIONS After only 2 months, the oxygen exposure showed only subtle influences on colour ; The most intense colour -French oak chips heavy toasted, followed by those with medium toast ; The evolution pattern regarding colour intensity in the case of American oak chips is similar to French oak chips (heavy toast inducing more colour than the medium toast); International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

RESULTS AND DISCUSSIONS Insensitive to oxygen exposure; French oak chips medium toasted – highest extraction ; French oak chips heavily toasted - lower polyphenol extraction ; The American oak chips are known to have lower tannin concentration and consequently the polyphenol extraction is, as observed, lower . International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

RESULTS AND DISCUSSIONS French American

CONCLUSIONS AND RECOMMENDATIONS The origin of chips The French oak chips are better suited for commercial uses, in comparison with the American ones. It has better values on both colour intensity and polyphenol extraction. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

CONCLUSIONS AND RECOMMENDATIONS The toasting level No matter the origin, a heavier toast resulted in higher values of colour intensity. The toasting level affects the polyphenol concentration by pyrolysis which significantly decreases their concentration in distillate. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

CONCLUSIONS AND RECOMMENDATIONS The oxygen level No visual effects in 2 months. Anyway, the values indicated slightly higher values of colour intensity and slightly lower values of Total Polyphenol Index, suggesting certain effects on acceleration of the maturation process. International Student Symposium "Hortus Academicus“ March 29, 2019 - Bucharest, Romania

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