0000000000476672
AUTHOR
Sven Karlović
High‐power ultrasound altered the polyphenolic content and antioxidant capacity in cloudy apple juice during storage
The aim was to investigate the influence of high‐power ultrasound treatment (HPU) on polyphenolic stability and antioxidant capacity in cloudy apple juice during 7 days of storage at 4°C. HPU (100 W, 30 kHz frequency) was operated at: (i) amplitude 40 versus 80%, (ii) the probe diameter 7 versus 10 mm, and (iii) treatment time of 3, 6, and 9 min. Total phenols (TP), total flavan‐3‐ols (TFL), and in vitro antioxidant capacity (DPPH and FRAP) were determined spectrophotometrically. Findings revealed that HPU significantly decreased TP, TFL, and antioxidant capacity in the samples. However, results indicated that examined sonication parameters, represented as the probe diameter and treatment t…
Non-Thermal Ultrasonic Extraction of Polyphenolic Compounds from Red Wine Lees
This study presents the results of conventional aqueous (CE) and non-conventional ultrasound-assisted (UAE) extractions of polyphenolic compounds from lees extracts of red wine varieties (Merlot and Vranac). The effect of ultrasound extraction time (t, s), and amplitude (A,%) from a 400 W ultrasound processor with different ultrasonic probes diameters (Ds, mm) on the amount and profile of polyphenolic compounds in the obtained extracts was investigated and compared to CE. The optimal conditions resulting in maximum extraction of phenolic compounds were: Probe diameter of 22 mm, amplitude 90% and extraction time for Vranac wine lees 1500 s and for Merlot wine lees extraction time of 1361 s. …