Phytochemical Profiles, In Vitro Antioxidants and Antihypertensive Properties of Wild Blueberries (Vaccinium angustifolium)

Cells generate free radicals as part of their normal physiological process. However, the production of excessive amounts of free radicals is a key contributor to various pathological conditions as an imbalance between oxidants (reactive oxygen/nitrogen species, ROS) and antioxidants leads to oxidative stress. Blueberries have bioactive properties that could reduce oxidative stress, blood pressure, and lipids in people at risk of chronic diseases associated with metabolic syndrome. The aim of this study, therefore, is to identify the bioactive phytochemicals in blueberries and determine the in vitro antioxidant and anti-hypertensive properties. Total phenolic content, total flavonoid content, radical scavenging, and angiotensin-1 converting enzyme inhibitory activity of freeze-dried blueberry powder were determined using standard methods. The results showed that the identified polyphenolic compounds include quercetin, gallic acid, cyanidin chloride, vitamin C, trans caffeic acid, procyanidin B1, and procyanidin B2. Blueberry samples exhibited significantly higher ACE-inhibitory activity (<i>p</i> < 0.05) of 32.7 ± 0.6%, 34.5 ± 4.7%, and 56.2 ± 2.0% at different concentrations of 0.1 mg/mL, 0.5 mg/mL and 2.0 mg/mL and also an increasing radical scavenging activities of 66.4 ± 2.9%, 72.3 ± 2.0%, and 83.4 ± 0.5% with increased concentrations at 1.0 mg/mL, 2.0 mg/mL, and 4.0 mg/mL, respectively. It had a high total phenolic and flavonoid content of 741.11 ± 5.0 mg gallic acid equivalents [GAE]/g) and 679.2 ± 5.0 mg catechin equivalents/g), respectively, at a concentration of 15 mg/mL. The results showed that blueberries are rich sources of bioactive compounds with significant antioxidants and antihypertensive properties that could benefit health, suggesting that they could be an important source of functional ingredients for potential nutraceutical development.