Pulsed electric field‐assisted extraction of mushroom ß‐glucan from Pleurotus pulmonarius by‐product and study of prebiotic properties

Summary Pleurotus pulmonarius is one of the most widely consumed mushrooms containing low calories and fat. This study aimed to extract polysaccharides mainly ß‐glucan from P. pulmonarius by‐products including cap and stem using pulsed electric field (PEF) and study their prebiotic properties. The by‐products were subjected to PEF at a field strength of 5, 7.5 and 10 kV cm −1 , a frequency of 15 Hz and a number of pulses of 12 000; then, the ß‐glucan content was determined with K‐YBGL assay test kit compared with a conventional extraction method using hot water at 100 °C for 6 h. In raw materials, crude carbohydrate contents in the cap and stem were 50.42% and 68.78%, respectively, and the ß‐glucan contents were 34.03% and 50.22%, respectively. After treated with PEF at 7.5 kV cm −1 , the highest yield of 4.18% with ß‐glucan content of 14.10% was achieved. And the stem treated at 10 kV cm −1 showed the highest yield of 2.34% with ß‐glucan content of 21.39%. Comparatively lower yield and ß‐glucan contents were found in the samples treated with hot water. Scanning electron micrographs suggested that PEF caused severe damage to both samples. Additionally, the study of the prebiotic properties revealed that both products exhibited the ability to stimulate the growth of target lactic acid bacteria and the production of short‐chain fatty acid. This study suggested that PEF could enhance the extraction efficiency of β‐glucan with prebiotic potential from P. pulmonarius by‐products.