Improved extraction methods for simultaneous recovery of umami compounds from six different mushrooms

Given the importance of umami compounds in culinary and food industries, this study sought to develop improved methods for simultaneous extraction of various umami taste components such as free amino acids (FAAs) and 5′-mononucleotides from shiitake mushroom (Lentinula edodes), oyster mushroom (Pleurotus ostreatus), tea tree mushroom (Agrocybe aegerita), and white, brown and portobello champignons (Agaricus bisporus). An optimized HPLC method was developed for efficient analysis of 5′-mononucleotides. Using multiple response optimization approach, optimum conditions required for extraction of total FAAs, total 5′-mononucleotides and total umami compounds were determined. The highest recovery of FAAs was obtained when mushrooms were extracted at room temperature for 180 min, while the highest 5′-mononucleotides were recovered by extracting at 70 °C for 30 min. Based on the desirability function, the optimal parameters of temperature, time and solvent volume for simultaneous recovery of umami components were found to be 70 °C, 30 min and 50 mL, respectively. Using the optimized method, white champignons and tea tree mushrooms were found to be the richest source for umami components. Water was found to be a better solvent than conventionally used 0.1 M HCl for extraction of FAAs from mushrooms.