The berries of Vaccinum corymbosum L. represent a rich source of polyphenolic compounds, which are known for their biological activities and their contributions to a healthy diet. The blueberry leaves are the main by-products of berry harvesting, annual significant amounts of leaves are discarded, which could be a valuable source of bioactive compounds.
In the present study, ultrasound-assisted extraction technology was used to determine and compare the chemical and biological profiles of leaves from six commercial blueberry(Vaccinium corymbosum L.) varieties, with the same geographical origin. Comparisons among cultivars aimed to evaluate differences between the polyphenolic composition of leaves and to analyze their antioxidant, antimicrobial, and antimutagenic activities.
For all six blueberry varieties, the class of phenolic compounds found in the highest concentration was hydroxycinnamic acids, followed by flavanols, and then closely flavonols.
Of all the phenolic compounds identified, feruloylquinic acid was identified in the highest amount for all varieties, at the lowest level, registered in the Spartan variety to the highest level, registered in the Nelson variety.
Regarding the group of flavonols, the major phenolic compound identified was rutin (quercetin-rutinoside), which recorded the highest values in the case of Toro, Nelson and Elliot leaves.
In the flavanol group, procyanidin dimer and procyanidin trimer were identified in remarkable quantities for all six leaf varieties.
The anthocyanin group, represented by three cyanidin derivatives, was present only in small amounts, for only three varieties: Elliot, Toro and Spartan.
The leaf extracts of the cultivars Toro, Elliot, and Nelson appear to be good sources of antioxidants, registering high percentage inhibitions of DPPH radicals. The blueberry leaf extracts had a strong antibacterial activity and a low antifungal capacity, and a low-to-moderate antimutagenic capacity towards Salmonella typhimurium TA98 and TA100 strains, with Toro leaf being the best candidate.
All of these biological activities indicate health-related benefits, recommending them as suitable candidates for medical and pharmaceutical applications. The present study adds significant knowledge to the field of blueberry leaves, supporting the ultrasound-assisted extraction technique as a useful and green method to provide alternative sources of bioactive compounds.
Audience Take Away Notes:
- Blueberry leaf extracts are a rich source of potent phenolic antioxidants.
- Cultivars significantly influence the phenolic composition and content, the antioxidant and antimutagenic capacities of V. corymbosum L. leaves