Quality characteristics of centrifuged broth from blanched Pleurotus eryngii and its application as instant drink

Abstract

Pleurotus eryngii (king oyster mushroom) has better pleasant aroma and culinary qualities, and it is also processed into different foods and snacks in Taiwan. The centrifuged broth obtained from the processing is usually discarded. Accordingly, the research was designed to analyze the composition of centrifuged broths from various grades of fruiting bodies and further to make instant drink from centrifuged broth with indigestible dextrin Fibersol-2 as the carrier. The centrifuged broth recovered consisted of 54.2–62.8% of the total weight of blanched mushrooms. The solids of the centrifuged broth contained free amino acids (15.20–34.23%), 5′-nucleotides (7.44–9.71%) and sugars and polyols (33.55–34.97%) and substantial amounts of ergothioneine (5.49–9.90%) and γ-aminobutyric acid (1.23–6.90%). Instant drinks SD13-40 and SD15-40 were rated the highest in color (6.3), flavor (5.7), and overall preferences (5.7–6.0) using a 7-point hedonic scale. Overall, the centrifuged broth could be developed as a functional food in the form of drink. Practical applications Pleurotus eryngii (king oyster mushroom) has better pleasant aroma and culinary qualities than other species of Pleurotus genus. In addition to fresh market, the mushroom is also processed into ready-to-eat food and vacuum-fried snack in Taiwan. The mushrooms are blanched first and centrifuged to obtain mushrooms with sponge structure for further procedures such as seasoning or drying. The centrifuged broth thus obtained is usually discarded; and therefore, it gives rise to a loading of sewage treatment since the centrifuged broth accounted for 54.2–62.8% of the total weight of blanched mushrooms. Besides, the solids of the centrifuged broth contained high amounts of taste components and substantial amounts of ergothioneine and γ-aminobutyric acid. Accordingly, the centrifuged broth was used to make instant drink with indigestible dextrin Fibersol-2 as the carrier. Based on the results obtained, the centrifuged broth could be developed as a novel functional food in the form of drink.