Physicochemical, nutritional, antinutritional and antioxidant properties of juice and wines from Rhododendron arboreum Sm. petals

Rhododendron arboreum Sm. is widely distributed in Nepal across the mid-hills and lower mountain region. Analyzing the petals of R. arboreum for juice and wine production may reveal potential health benefits and novel sensory experiences. The present study aims to analyze and compare physicochemical properties, proximate composition, phytochemical content, antioxidant activity, mineral content, antinutritional factors, antimicrobial activities, and sensory attributes of juice and three types wine (H1, H2, and H3) based on different methodology. It was observed that wine H2 has a maximum TPC (9.96 ± 0.15 mg/mL), TFC (7. 11 ± 0.05 mg/mL), and TAC (162.16 ± 2.3 mg/mL), correlating with its strong antioxidant activity (82.01 % DPPH scavenging) and improving colour and antioxidant properties, compared to wine H1 and H3. The highest concentration of minerals was seen in the juice, followed by wine (H2). Antimicrobial screening revealed that juice and wine extract both have antimicrobial activity, with wine extract H2 having the best activity against gram-positive bacteria. The preparation method chosen can have a significant impact on the quality of the wine H2, which was significantly better in comparison to wine H1 and H3. In conclusion, the present study has demonstrated how the optimization of fermentation condition acts as a positive tool in upgrading the physicochemical, nutritional, and functional properties of R. arboreum juice. The findings highlighted the potential of R. arboreum wine, especially wine H2, as functional beverages. These insights can guide local beverage development in Nepal, offering economic benefits and preserving traditional practices.

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