The Impact of Thermal and Electrical Pretreatments and Antibrowning Solution on the Chlorogenic and Dicaffeoylquinic Acid Extraction Yield from Endive Roots

Forced endive roots (FERs) contain beneficial antioxidant compounds such as chlorogenic acid (5-CQA) and dicaffeoylquinic acids (diCQAs). This study compared the extraction yields of 5-CQA and diCQAs using a biomass pressing method with various pretreatments, including pulsed electric field (PEF) and microwave (MW), against the solid–liquid extraction method (water, 90 °C, 30 min). The results indicated that the MW pretreatment achieved the highest yields, extracting 28 ± 2% of 5-CQA and 13 ± 1% of diCQAs, surpassing the solid–liquid method. Furthermore, the oxidative degradation of CQAs was studied, and it appeared that this reaction was enhanced by PEF pretreatment. An antibrowning solution (ABS) was successfully tested to reduce this oxidation and protect CQAs. An extraction process utilizing MW and PEF pretreatments combined with an ABS solution achieved yields of 65 ± 1% for diCQAs and 80 ± 5% for 5-CQA, significantly outperforming the solid–liquid extraction method.