Research into the production of blueberry wine indicates that the libation can retain numerous advantageous compounds from the original berry, albeit fermentation and thermal management impact the final content of nutrients.
Antioxidant-heavy blueberries — a staple in many a breakfast beverage — can also be transformed into wine. However, does the necessary heat and duration for fermenting this robust berry remove any of its potential health-benefiting components? In ACS Food Science & Technology, investigators look into the impact of fermentation on the bioactive substances and the antioxidant propensity in blueberry wine. The conclusions illustrate that blueberry wine conserves some of the berries’ nutrients, and the authors document methods to conserve these elements effectively in this nutritious drink.
With an abundance in bioactive elements, blueberries have become a component of increasingly more culinary products and drinks — including wines. The effects of the wine production process, particularly fermentation and thermal impact, on these compounds and their antioxidant effects (i.e., their capacity to counteract harmful free radicals) are not fully understood. Thus, Maria Serratosa and her team explored how these dynamics influence the health value of blueberry wine.
Study Insights and Methodology
The team embarked on their examination with 8 liters of blueberry extract sourced from crops in southern Spain and apportioned it into separate 1-liter flasks. Four flasks were assigned to a water bath at 63 degrees F, the remaining four at 70 degrees F. In each temperature condition, two flasasks subject to an extensive (complete) fermentation to yield dry wine, with the remaining two subjected to a brief (partial) fermentation to produce sweeter wine. They evaluated and paralleled the levels of bioactive substances in the primary extract and in the wine post-production. Additionally, a common assay for neutralizing free radicals was employed to determine and contrast the antioxidant efficiency of these bioactive substances in both the juice and the wines. Specifically, they analyzed:
- Anthocyanins: antioxidants that are the reason for the hue in red wine.
- Flavonols: beneficial antioxidants.
- Flavan-3-ols: compounds that might aid in sustaining vascular suppleness.
- Tannins: contribute to the astringent taste in wine.
- Vitamin C: an antioxidant crucial for tissue rejuvenation and immune defense.
In their findings, it was shown that anthocyanin, tannin, and flavonol quantities reduced with extended fermentation intervals. In contrast, the quantity of flavan-3-ols amplified with the length of fermentation. However, the duration of fermentation didn’t seem to affect the vitamin C content in the wines. Instead, the wine held at 70 F contained approximately half the vitamin C compared to wine maintained at 63 F. And despite a general drop in antioxidant levels, the wines still presented higher antioxidant activities than the initial blueberry extract.
Generally, fermenting blueberry extract can evolve into a wine that sustains the health properties of the berries, yet temperature control and fermentation duration can modify the nutritional composition of the resulting beverage, as reported by the researchers.
Reference: “Investigating the Effect of Temperature and Fermentation Duration on the Evolution of Bioactive Substances, Antioxidant Potency, and Colour Transformation in Blueberry Wines” by M. Angeles Varo, Juan Martín-Gómez, Julieta Merida and Maria P. Serratosa , 2 May 2024, ACS Food Science & Technology.
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