Effects of Acidification and Blanching Pretreatments on Nutraceutical Properties, and Consumer Acceptability of Cherry Laurel (Prunus laurocerasus L.) Nectar-type Beverages

Cherry laurel (Prunus laurocerasus L.) is an underutilized regional fruit rich in anthocyanins and phenolic compounds native to the Eastern Black Sea of Turkey with potential for functional food development and regional gastronomy. This study investigated the effects of acidification (citric acid to pH 3.0) and blanching (90°C, 2 min) on anthocyanin retention, antioxidant properties, and consumer acceptability of cherry laurel nectar-type beverages. A 2×2 factorial design (acidification × blanching) yielded four products (P1–P4). Acidification was the dominant factor for anthocyanin retention (P < 0.05), approximately doubling monomeric anthocyanin content relative to the non-acidified samples. Both pretreatments improved anthocyanin retention, with acidification exerting a stronger effect on polymeric color reduction. Blanching significantly improved TPC and antioxidant capacity (CUPRAC and DPPH) by approximately 20% (P < 0.05). The acidified and blanched product (P4) received the highest mean sensory scores for appearance (5.43 ± 0.22), taste (4.78 ± 0.24), and overall acceptability (4.86 ± 0.21). In conclusion, acidification is critical for anthocyanin retention and color preservation during processing, while blanching effectively enhances antioxidant properties. The combination of both treatments produced a nectar-type beverage with the highest bioactive content and consumer acceptability, providing a scientific basis for optimizing cherry laurel beverage production.