It is well documented that red wine has certain properties which provide health benefits when consumed in moderation. Polyphenols in particular, which are concentrated in the skins and seeds, provide protection against cardiovascular diseases and act as antioxidants which act to prevent the accumulation of LDL-cholesterol. As a result of this antioxidant property, polyphenols in red wine can potentially delay the development of atherosclerosis and decrease coronary heart disease mortality.
White wine, however, does not share these properties with their red wine counterparts. White wines typically do not have polyphenols present in such large quantities as red wine, and the antioxidant activity is also subsequently lower. For those that drink primarily white wines, be it as the result of an allergy or a simple taste preference, the great health benefits associated with drinking wine are greatly reduced; with the exception of Champagne/Sparkling wine, which has been shown to have similar health benefits as drinking red wine (read that article by clicking here).
One of the main differences in the production of red and white wines has to do with skin contact during, and in some cases after, the fermentation process. Typically, white wine is produced with no skin contact, with a clarification step added before fermentation begins, and followed by the addition of yeast to convert the must to wine. Sulfur dioxide (an antioxidant) is frequently added, in order to inhibit bacterial and wild yeast growth. With red wine, this fermentation process is completed with the skins in contact with the must/wine the entire time (also known as maceration), allowing the absorption of color, and other compounds found in the grape skins into the wine. Since polyphenols are primarily located in the skin, it is the maceration process in red wine production that allows the extraction of phenols and absorption into the red wine. Since white wine production does not usually involve this maceration step, polyphenol levels and the associated health benefits therein are dramatically reduced.
In the study reviewed today, that of which was published in journal European Food Research Technology this summer, the authors sought to determine if adding a maceration step into the production of white wines would increase the concentration of polyphenols in the finished wine, leading to greater health benefits of white wines, on a scale comparable to their red wine counterparts. Instead of adding yeasts, the authors relied on the natural yeasts in the must to carry out fermentation, and sulfur dioxide was not added, since the natural polyphenol antioxidants present in the skin would be present in the must after the maceration process. By comparing the same varietal wines produced with and without the maceration step, the authors aimed to determine if using a maceration step in white wine production would produce wines with higher polyphenol concentrations, thus an overall “healthier” wine.
Fourteen macerated and unmacerated white wines from Friuli-Venezia Giulia (Italy) and Istria (Croatia) were analyzed. The following grape varieties were studied: Ribolla Gialla, Tocai Friulano, Malvazija, Pinot Gris, and Sauvignon Blanc, in addition to a blended wine of Malvazija, Sauvignon Blanc, and Pinot Gris.
Total phenolic concentration was measured using UV Spectrophotometry, based on a colormetric oxidation/reduction reaction. Individual polyphenols were analyzed and measured using HPLC methods. Antiradical activity was measured using the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) in a spectrophotometric test.
- The quantity of total phenols in the macerated white wines ranged from 1,654mg/L (+/-17) to 2,103mg/L (+/- 60), with an average of 1,859mg/L (+/- 38).
- The quantity of total phenols in the nonmacerated white wines ranged from 291mg/L (+/- 4) to 832mg/L (+/-31), with an average of 527mg/L (+/-21).
o White wines with a maceration step contained considerably higher amounts of total phenols than white wines made in the more traditional sense (without a maceration step).
o The highest total phenol value was associated with the blended wine (Mal. Sauv. Blanc., and P. Gris).
o After taking vintage and variety into consideration (which can be a source of variation in total phenol content), the direct comparison of macerated and unmacerated wines from the same grape variety and harvest year showed there were significantly higher phenol concentrations in all macerated white wines than nonmacerated white wines.
- The total phenol values observed are consistent with the levels of total phenols in red wines from other published data.
- The most abundant individual polyphenol was caftaric acid, with the highest concentration occurring in the blended wine (53.10mg/L).
o The average concentration of caftaric acid in macerated white wines was 18.46mg/L.
o The average concentration of caftaric acid in nonmacerated white wines was 8.98mg/L.
o The amount of caftaric acid in macerated white wines was about double the amount in nonmacerated white wines, thereby the maceration processes caused a significant increase in caftaric acid in the white wines studied.
- The concentration of caffeic acid was highest in the blended wine (5.45mg/L), which is within the normal range of caffeic acid found in red wines.
o The concentrations of caffeic acid did not differ significantly between macerated and nonmacerated white wines, with concentrations of 1.89mg/L and 1.77mg/L, respectively.
- The concentration of caffeic acid ethyl ester was highest in the blended wine (2.09mg/L)
o The average concentration in macerated wines was 1.02mg/L, and the average concentration in nonmacerated wines was 0.85mg/L.
- In macerated wines, ferulic acid was only detected in the blended wine (1.04mg/L), whereas in nonmacerated wines, it was detected in only 4 samples of the varietals only. Amounts detected were comparable to those found in red wines.
- p-Coumaric acid concentrations ranged from 0.32mg/L to 1.37mg/L in nonmacerated wines, which is comparable to concentrations found in red wines. In macerated wines, p-Coumaric acid was only detected in the blended wine (1.32mg/L), plus one other varietal.
- The concentration of p-coutaric acid was found in the blended wine (17.09mg/L), which corresponds with the average value of p-coutaric acid in Italian red wines.
o Despite the high concentration in the blended wines, the average concentration of p-coutaric acid in macerated wines (5.39mg/L) was only slightly higher than the concentrations in nonmacerated wines (4.59mg/L).
- There were no significant differences in the concentration of fertaric acid in macerated (1.15mg/L) and nonmacerated wines (1.13mg/L).
- There were no significant differences in the concentration of 2-S-glutathionylcaftaric acid in macerated (2.55mg/L) and nonmacerated wines (2.56mg/L).
- The concentration of gallic acid in macerated wines ranged from 7.56mg/L to 19.38mg/L, which is comparable to concentrations in red wines. The average concentration of gallic acid in nonmacerated wines was 2.29mg/L.
- The concentration of catechin in macerated wines was highest in the blended wine (21.35mg/L), which is comparable to the values found in red wines.
o The mean concentration of catechin in macerated wines was 12.61mg/L, which is comparable to the values found in red wines.
o In nonmacerated wines, catechin was only detectable in two wine samples, with values of 6.84mg/L and 7.30mg/L.
- The concentration of epicatechin was highest in the blended wine (13.70mg/L), the value of which corresponds with the epicatechin values in red wines.
o The mean concentration of epicatechin was significantly higher in macerated wines (8.58mg/L) than nonmacerated wines (4.77mg/L).
- The concentration of stilbene trans-resveratrol was highest in the blended wine (1.95mg/L), which is even higher than some red wines.
o In macerated wines, the mean concentration of stilbene trans-resveratrol was 0.94mg/L.
o In nonmacerated wines, the mean concentration of stilbene trans-resveratrol was 0.48mg/L (about half that of the value found in macerated wines).
- Macerated wines were much greater DPPH scavengers, with inhibition rates of about 90% (which is comparable to red wines).
- Conversely, nonmacerated wines exhibited much poorer antiradical properties, with most samples showing less than 50% inhibition.
o In a nutshell, macerated wines are significantly better at blocking radicals than nonmacerated wines.
From the results presented in this study, it is clear than white wines produced with a maceration step contain significantly more polyphenols (total and some individual) than white wines produced in a more traditional way, without the maceration step. Another important thing to note is that there appears to be an even greater amount of polyphenols present when individual grape varieties are blended. Since the highest concentrations of nearly all individual polyphenols measured were found in the blended wine, it can be inferred that by blended the individual wines, there is a sort of synergistic effect, and the “whole is more than the sum of the parts”. It appears as though when the different wines are blended together, a sort of “super wine” is created, resulting in the highest levels of polyphenols in the final wine.
As a result of the natural antioxidant properties of the polyphenols in the skins, by macerating the skins with the wine, there was no need for the addition of sulfur dioxide, which is promising for those with a sulfur dioxide allergy. Also, the yeasts already present in the grapes/must were able to fully carry out the fermentation process, thus removing the necessity of adding other yeasts to help the process along.
Though the chemical analysis is promising, the one side of the story this study does not address is whether or not sensory characteristics of the finished wine are altered when producing a white wine with a maceration step included. Other studies have surely tackled this subject, but to make the story complete, it would be ideal for a study to contain both the chemical analysis and the sensory analysis of macerated versus nonmacerated white wines.
Assuming all sensory characteristic being equal (which may not be the case, but we’ll say it is for a minute), this study shows great promise for creating a white wine that’s nearly identical to red wine, in regards to its’ health benefits for consumers. Up until now, it has primarily been red wine drinkers who have been benefitting from the reported health benefits of wine. Perhaps with a maceration step in the fermentation process, white wine drinkers may finally achieve the same health benefits as their red wine-drinking counterparts.
How about you all? Do you have any experience with macerated white wines? I’d love to hear what you all think! Please feel free to comment below!
Source: doi: 10.1007/s00217-011-1535-4
I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!