2.6.8. Determination of total phenolic content of H. erinaceus extract, wine and vinegar
The total phenolic content was determined using Folin-Ciocalteu reagent in accordance with the method of Velioglu, Mazza, Gao, and Oomah (1998). Folin-Ciocalteu reagent was diluted 2-fold in deionized water. The sample (0.25 ml) was mixed with 0.75 ml of diluted Folin–Ciocalteu reagent and 2 ml of Na2CO3 (2.0%, w/v), and then incubated at 36 °C for 30 min. Absorbance was measured at 750 nm with a UV–VIS spectrophotometer. The concentration of total phenols was expressed as mg ml−1 of extract