# Bioactive and antioxidant properties in highbush blueberry cultivars: identifying superior cultivars for nutritional biofortification

## TL;DR

This study compares 21 highbush blueberry cultivars to identify those with the highest levels of health-promoting compounds like antioxidants and phenolics, which can help breed better nutritional varieties.

## Contribution

The study provides a comprehensive biochemical comparison of blueberry cultivars, revealing genotypic diversity and metabolic clusters for targeted breeding.

## Key findings

- Total phenolic content varied 2.7-fold, with 'Misty', 'Twilight', and 'Unknown' showing the highest values.
- Total anthocyanin content varied 4.4-fold, with 'Eureka', 'Twilight', and 'Rossini' having the highest accumulation.
- PCA identified four distinct metabolic clusters, including sugar-anthocyanin co-accumulators and superior antioxidant types.

## Abstract

Highbush blueberries (Vaccinium corymbosum L.) are recognized as functional foods with exceptional health-promoting properties, yet comprehensive comparative evaluations of cultivar-dependent variation in bioactive compounds remain limited for breeding applications.

This study characterized phenolic profiles, anthocyanin content, sugar composition, and antioxidant capacity of 21 highbush blueberry cultivars (19 Southern Highbush, 2 Northern Highbush) grown under uniform conditions at Liaoning Institute of Pomology, China. Phenolic compounds were quantified by HPLC-DAD, sugars were analyzed by HPLC with refractive index detection, and antioxidant activity was assessed using DPPH radical scavenging assay. Data were analyzed using ANOVA, Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis.

Significant cultivar effects (p<0.001) were detected for all biochemical parameters. Total phenolic content exhibited 2.7-fold variation (253–688 mg GAE/100 g DW), with 'Misty', 'Twilight', and 'Unknown' showing highest values. Total anthocyanins varied 4.4-fold (603–2678 mg/100 g DW), with 'Eureka', 'Twilight', and 'Rossini' demonstrating superior accumulation. Eight major phenolic compounds were identified, with chlorogenic acid (61.44–223.89 mg/100 g DW) predominating among phenolic acids and malvidin-3-glucoside as the principal anthocyanin. Sugar profiling revealed glucose and fructose as predominant carbohydrates (92–97% of total sugars), with total sugar content ranging 2.9-fold (6.13–18.06 g/100 g DW). DPPH radical scavenging capacity ranged from 35.26% to 69.08%, strongly correlating with total phenolic content (r=0.73). PCA explained 50.1% of cumulative variance and differentiated cultivars into four distinct metabolic clusters: sugar-anthocyanin co-accumulators ('Rossini', 'Twilight'), superior antioxidant types ('Misty', 'Magnifica', 'Unknown'), gallic acid specialists ('Jewel', 'L503', 'Ventura'), and cyanidin-3-glucoside specialist ('Eureka').

These findings reveal extensive genotypic diversity in primary and secondary metabolism among highbush blueberry cultivars, providing valuable germplasm resources and selection criteria for breeding programs aimed at developing elite cultivars with enhanced nutritional quality and superior antioxidant properties.