Dual-frequency countercurrent ultrasonic-assisted extraction of the cold brew coffee and in situ real-time monitoring of extraction process

Autor: Huimin Liu, Dandan Liu, Wuli Wang, Xinyan Zhang, Jamila Tuly, Hanhan Li, Haile Ma
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Ultrasonics Sonochemistry, Vol 111, Iss , Pp 107118- (2024)
Druh dokumentu: article
ISSN: 1350-4177
DOI: 10.1016/j.ultsonch.2024.107118
Popis: This research aimed to examine the effect of countercurrent ultrasound on extraction efficiency of cold brew coffee (CBC). The quality and flavor of CBC obtained by ultrasonic-assisted extraction (UE) were evaluated and compared with traditional extraction (TE). Meanwhile, the UE process was monitored in situ real-time using a near-infrared (NIR) spectrometer. The optimal UE parameters obtained by experiments were dual-frequency of 20/28 kHz, countercurrent ultrasonic treatment time of 50 min, ultrasonic power density of 320 W/L, and material-liquid ratio of 1:15. Under the optimal parameters, the total dissolved solids content (TDS) and extraction yield (EY) were 1.63 % and 20.52 %, respectively. This resulted in an 83.33 % improvement in efficiency matching the TDS and EY of a 5-h TE CBC. In comparison with the control, the contents of total polyphenols, total sugars, and total lipids after ultrasonic treatment increased by 13.79 %, 28.49 %, and 333.33 %, respectively, while the total acids content decreased by 27.81 %. HPLC and HS-SPME-GC/MS analysis showed similar non-volatile and volatile flavor components between UE and TE CBC. A quantitative partial least squares (PLS) prediction model was developed to monitor TDS and CGA levels during the UE CBC. This model demonstrated excellent calibration and prediction performance. (TDS: Rc = 0.9281; RMSECV = 0.0694; Rp = 0.9514; RMSEP = 0.0631. CGA: Rc = 0.9086; RMSECV = 0.0316; Rp = 0.9467; RMSEP = 0.0212). This study explored an efficient approach for the industrialization of CBC production and provided theoretical support for developing an intelligent control system for its process.
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