Effect of Processing Parameters on the Content of Bioactive Compounds of Prunus spinosa L. Fruit Tinctures

Blackthorn (Prunus spinosa L.) fruits are traditionally used to produce tinctures and are known for their high content of bioactive compounds with antioxidant, anti-inflammatory, and antimicrobial effects. As demand for functional foods increases, it is important to optimize production methods to preserve these health-promoting properties. This study investigated how various parameters influence the polyphenol content and antioxidant capacity of blackthorn tinctures. In the first stage, five ethanol concentrations (40-80% v/v) were tested, with 80% proving most effective for polyphenol extraction. In the second stage, the influence of fruit pre-treatment (blanched and pricked), sugar addition timing, and maceration duration (28-84 days) was assessed using tinctures made with 80% ethanol. Maximum total polyphenol content was recorded on day 84 in the variant with whole unprocessed fruits, and sugar added at the beginning. Phenolic acids, especially neochlorogenic acid, dominated the extracts. Anthocyanin concentrations reached their maximum during the early phase of maceration and subsequently exhibited a progressive decline over time, likely due to their inherent chemical instability under extraction conditions. Flavan-3-ols and phenolic acids remained more stable, particularly when sugar was added at the beginning. Antioxidant activity strongly correlated with polyphenol content and was highest in samples rich in polymeric procyanidins.