Blueberry balsamic vinegar: bioactive compounds and antioxidant activity during processing and assessment of diverse evaporation techniques for juice

Abstract

Blueberries are widely recognized for their beneficial health effects due to their bioactive compounds content. In addition, balsamic vinegars trade developed quickly because of their wide acceptance in gourmet food. A novel product made with second quality berries, being suitable for human consumption, i.e., blueberry balsamic vinegar, was evaluated. This work aimed to assess changes in Total Anthocyanins (TA), Total Phenolics (TP), and antioxidant activity during production process of blueberry balsamic vinegar, at the following stages: raw material, blueberries juice after enzyme treatment, blueberries alcoholic substrate, blueberries vinegar, concentrated blueberry juice and blueberries balsamic vinegar. Additionally, three alternative evaporation systems, rotary vacuum evaporator, microwave and vacuum microwave, were evaluated in order to determine the concentration method that best retains TA and TP in blueberry juice for its further use in this process. The highest TA and TP retention was achieved by blueberry juice concentration with a rotary vacuum evaporator. On the other hand, both alcoholic fermentation and acetification negatively affected those compounds and antioxidant activity during vinegar production. However, mixing with concentrated juice to obtain blueberry balsamic vinegar allowed balancing nutrient concentration reductions due to processing. The present study showed that production of blueberry balsamic vinegar gives rise to an interesting possibility to reduce losses due to fruit waste while getting added value products with healthy qualities.