Solid State Fermentation Of Edible And Medicinal Fungi Improves Functional Properties Of Wheat Bran And Bran-Containing Products

In this paper,the wheat bran was fermented by several medicinal and edible fungi,such as Fomitopsis pinicola(F.pinicola),Pleurotus nebrodensis and Auricularia polytricha(Mont.)Sacc.The water absorption index(WAI),water solubility index(WSI),swelling,total antioxidant capacity,total phenolic contents,alkylresorcinols(ARS)contents and flavor of bran were compared.The results showed that: The bran fermented by F.pinicola had the best effect.Compared with unfermented bran,the WAI of fermented bran increased by 13.06%,and the WSI and swelling were 3.78 and 1.87 times of unfermented bran;The total antioxidant capacity of fermented bran was reached the highest at 4 d,which was 5.73 times of unfermented bran.the contents of total phenolic and ARs was reached the highest at 6 d,which was 5.91 and 1.59 times of unfermented bran;The results of electronic nose showed that the response values of bran fermented of 6 d was the highest;GC-MS analysis the bran of unfermented,F.pinicola fermented,Pleurotus nebrodensis fermented and Auricularia polytricha(Mont.)Sacc fermented detected 38,45,43 and 41 volatile components.After fermentation,the relative contents of aldehydes and esters were decreased,and the relative contents of ketones and phenolics were increased.Among them,the relative content of 4-ethylguaiacol in bran fermented by F.pinicola reached 60.459%,and the bran fermented by Pleurotus nebrodensis and Auricularia polytricha(Mont.)Sacc was 18.032% and 1.414%.The results of the structure and related enzyme activities of wheat bran fermented by F.pinicola showed that: the p H of bran first increased and remained at about 7 for 2-6 d;Scanning electron microscope observation revealed that the originally compact and smooth surface of bran became rough and porous;Fluorescence microscope observation revealed that the cell wall of the fermented bran was broken and the protein were broken down;The activity cellulase,xylanase and ferulic acid esterase of bran fermented by F.pinicola showed a trend of increased first and then decreased with the fermentation time,which reached 19.72,15.27 and 8.53 U / g.The fermented bran was added back to baked whole wheat bread.The texture analysis of bread found that: with the increased in the time of bran fermentation,the hardness,gumminess and chewiness of whole wheat bread were all decreased,the springiness and adhesiveness showed a trend of increased and then decreased.At the same time,the bread added with fermented 2,4,and 6 d bran protein contents was increased,,while the content of cellulose,starch and phytic acid decreased gradually;the bread with added fermented 4 d bran had the highest total antioxidant capacity,which was 14.99% higher than the control,an increase of 90.24% compared to the commercially available whole wheat bread.Compared with the control,the total phenolic and ARs contents were increased by 47.84% and 43.61% respectively,and compared with the commercially available bread by 80.00% and 62.34%.The effects of the amount of bran,yeast and gluten added on the sensory evaluation of bread were analyzed by a single factor test,and the orthogonal test was used to optimize the recipe of whole wheat bread.The results showed that: the best formula of whole wheat bread was bran 7.5%,yeast 2.75 g and gluten 8 g.