Rapid Quantification of Grape Juice Phenolics Using UPLC-QDa Mass Detection

Rapid Quantification of Grape Juice Phenolics Using UPLC QDa Mass Detection

Importance of the Topic

Phenolic compounds in grapes and grape products provide key antioxidant benefits by combating oxidative stress related to various diseases. Accurate profiling of these compounds supports quality control, nutraceutical evaluation and advances in food chemistry research.

Study Objectives and Overview

This study aimed to develop and validate a rapid ultra performance liquid chromatography method coupled with mass detection for the simultaneous quantification of 16 phenolic compounds in 49 grape juice samples from diverse grape varieties and agronomic conditions.

Methodology and Sample Preparation

Standards for anthocyanins, flavanols, procyanidins and flavonols were prepared and diluted into calibration curves. Grape juices were centrifuged, diluted to fit the calibration range and injected without extensive cleanup. Chromatographic separation was achieved in 4.5 minutes using formic acid–water and methanol–formic acid–water gradients, reducing solvent consumption by over 90 percent.

Used Instrumentation

• ACQUITY UPLC H-Class System with BEH C18 column and guard column
• ACQUITY QDa Mass Detector operated in Selected Ion Recording mode
• Empower Software for system control and data processing

Main Results and Discussion

Anthocyanins dominated the phenolic profile, with malvidin-3,5-diglucoside as the most abundant compound. Organic juices generally exhibited higher total phenolic levels than conventional juices across most varieties. Aging decreased overall phenolic content except for myricetin, which increased over time. Soil fertilization influenced phenolic accumulation, with intermediate fertilization yielding the highest values in Niagara Rosada juices. Flavanols and flavonols were detected at lower concentrations, with catechin and myricetin as the most prevalent representatives in their classes.

Benefits and Practical Applications

• Fast analysis of 16 phenolic compounds in under five minutes per sample
• Detection limits down to low microgram per liter levels for routine quality control
• Minimal sample preparation without complex purification steps
• Significant reduction in solvent use aligned with green chemistry principles

Future Trends and Opportunities

Further developments may include high-throughput phenolic screening for breeding programs, integration with other green analytical techniques, expansion to other fruit matrices and deeper insights into compound stability during storage and processing.

Conclusion

The validated UPLC QDa mass detection method delivers rapid, sensitive and sustainable quantification of a broad range of phenolic compounds in grape juice, supporting routine analysis and research in food chemistry and nutraceutical assessment.

References

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