Title:Phenolic Profile and Antioxidant Capacity of Skin-contact White Wines
Volume: 21
Issue: 4
Author(s): Milena M. Ramirez-Rodrigues, Alexa Perez-Alva and Rosalía Garcia-Torres*
Affiliation:
- Department of Family and Consumer Sciences, California State University, Northridge, Los Angeles, CA,
USA
Keywords:
Skin-contact white wine, phenolic profile, antioxidant capacity, principal component analysis, total phenolic content, minerals.
Abstract:
Background: Skin-contact white wines (also known as amber, orange, or macerated
white wines) go through extended maceration during fermentation, giving the wine a characteristic
amber- or orange-like color and a unique flavor.
Objective: This study aimed to compare the polyphenolic profile and antioxidant capacity of selected
skin-contact white wines from three different regions including the ones prepared with the
traditional Kakhetian method.
Methods: Samples consisted of nine commercially available skin-contact white wines from
Greece, United States and Georgia. Wines from Georgia were prepared with the traditional Kakhetian
method. Several physicochemical properties, total phenolic content (TPC), ß-carotene, and
mineral content were determined.
Results: TPC ranged from 447 to 2211 mg GAE/L, antioxidant capacity measured using ABTS
and DPPH ranged from 643 – 2088 μmol TE/L, and 584 – 4421 μmol TE/L, respectively. Mn, Ca,
Mg and P content ranged from 3.6 – 18.2 mg/L, 406 - 772 mg/L, 1530 – 2770 mg/L, and 530 –
2200 mg/L, respectively. A Principal Component Analysis (PCA) of the eight phenolic compounds
that were present in more than one wine (gallic acid, vanillic acid, caffeic acid, caftaric
acid, 4-CQA=4-Caffeoylquinic acid, p-coumaric acid, catechin, and epicatechin) identified two
groups of skin-contact wines. Group one included the three amber wines from Georgia (samples 1
to 3) made following the Kakhetian method and one orange wine from the USA (sample 9).
Group two included the remaining samples from the USA (samples 7, 8) and the three samples
from Greece (samples 4-6).
Conclusion: Skin-contact white wines, despite having an extended maceration during fermentation
in common, can be quite different in polyphenol content and antioxidant capacity, perhaps
due to differences in the processing conditions.
