Study of the influence of Hippophae leaves on the antioxidant activity of wines

Postgraduate Thesis uoadl:1332745 598 Read counter

Unit:
Κατεύθυνση Βιομηχανική Χημεία
Library of the School of Science
Deposit date:
2017-03-07
Year:
2017
Author:
Tzachristas Alexandros
Supervisors info:
Λιούνη Μαρία, Αναπληρώτρια Καθηγήτρια, Χημικό, ΕΚΠΑ
Original Title:
Μελέτη της επίδρασης της προσθήκης φύλλων ιπποφαούς στην αντιοξειδωτική ικανότητα οίνων
Languages:
Greek
Translated title:
Study of the influence of Hippophae leaves on the antioxidant activity of wines
Summary:
In this thesis we study the influence of Sea Buckthorn Leaves (Hippophae rhamnoides) on the antioxidant activity of wines. Two experiments were conducted where we examined the influence of increasing quantities of Sea Buckthorn leaves during the maturation phase of certain wines (0-1,6 g/l Sea buckthorn Leaves) and during the fermentation of Moschofilero without sulfites (0-0.8 gr/L Sea Buckthorn Leaves). Specifically we determined fermentation kinetics, the analytical characteristics prior and after the addition of the leaves and the antioxidant activity of the wines via the spectroscopic methods DPPH, FRAP and Folin-Ciocalteu.
Fermentation kinetics and the typical analytical characteristics of the wines were not influenced. The antioxidant acitivity and the colour intensity of white wines increased in all cases. The addition of 0.8 gr/lt of SBT Leaves increased Antioxidant Activity via the DPPH assay from 23 to 58%. Equally the reducing power as determined via the FRAP assay increased from 35 to 67%, the Folin Ciocalteu index increased from 12 to 27% and the colour intensity increased from 39-50% (ABS420SS15=0.137 0.191, ABS420RS=0.0560.080). The contribution of up to 1.6 g/l of Sea Buckthorn Leaves to the red wine examined was very low due to the already high phenolic concentration of the red wine.
The addition of SBT Leaves in concentrations up to 0,8 gr/lt in the initial stages of the alcoholic fermentation of Moschofilero without the presence of sulfites wasn’t capable to inhibit the further oxidation of the samples after the end of the fermentation. Results show that the addition of Sea Buckthorn leaves increases the antioxidant activity in wine and depending on the dosage may help prevent oxidation to a certain degree.
Main subject category:
Science
Keywords:
Wine, DPPH, FRAP, Folin Ciocalteu, Sea Buckthorn leaves, antioxidant activity
Index:
No
Number of index pages:
0
Contains images:
Yes
Number of references:
115
Number of pages:
139
File:
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dissertation_final.pdf
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