Fresh white petals of Rosa hybrida Colorado were harvested, dried, and ground, after which the crushed petals were disinfected with ethanol and dried at 80°C for 24 hours. The dried white rose petal powder was then extracted by 50% ethanol at 60°C for three hours, and the extract was completely dried with a vacuum evaporator to obtain WRE.
This was then added to both red and white wine. The study found that “as WRE content in (the) wines increased, the total polyphenol concentration also increased with respect to the amount added in both red and white wines”.
It also said that the addition of WRE did not affect the taste, aroma, sweetness or astringency of either the red or white wine, although it did lighten the colour of the red wine and make the white wine appear more yellow.
The fermentation profile of parameters such as CO2 production rate, pH and final ethanol concentration remained largely unaffected by the addition of WRE. However, adding WRE to white wine resulted in slower depletion of its soluble sugars, “revealing an inhibitory effect of acidity and WRE (0.25%) on ethanol fermentation of yeast”.
The study stated that while the “polyphenolic content of wine can be fortified by the simple addition of WRE”, this effect was more dominant in white wine.
White rose petals, which are edible and contain a high concentration of phenolic compounds, are known for their antioxidant, anti-allergy, antibacterial, anti-inflammatory and anti-microorganism qualities.
The study concluded that it had proven the possibility of enhancing the health benefits and nutritional of red and white wines by the “simple addition of WRE” without drastically altering their characteristics, and that considering WRE’s antibacterial, anti-allergy, anti-inflammatory and antioxidant properties, it could be “used as an additive in the production of various beverages or foods”.
Source: Journal of Microbiology and Biotechnology
“Enhancing Antioxidant Activities of Wines by Addition of White Rose Extract”
Authors: Hyunbin Seong, et al.