Quality and evaluation of Auricularia cornea on different cultivation substrates

【Objective】To study the quality differences of Auricularia cornea cultivated with eucalyptus sawdust，eucalyptus bark and miscellaneous sawdust，respectively. This study would provide a theoretical basis for the application of eucalyptus sawdust and eucalyptus bark in the edible fungi cultivation. 【Method】The fruiting body of A. cornea cultivated with different substrates（eucalyptus sawdust，eucalyptus bark and miscellaneous sawdust） were used as the test material to investigate the main agronomic traits，amino acid composition and texture properties，respectively. The quality of A. cornea in different cultivation substrates was comprehensively evaluated by correlation analysis and principal component analysis. 【Result】There were no significant differences in the start time of colonization and mycelium growth rate of A. cornea from different cultivation substrates（P>0.05），and the mycelium was dense，white，and thick on substrates of eucalyptus sawdust and eucalyptus bark. Compared with the cultivation substrate of eucalyptus bark and miscellaneous sawdust， the first tide yields of A. cornea cultivated on eucalyptus sawdust significantly increased by 6.95% and 14.94% （P<0.05. the same below），and the second tide yields significantly increased by 19.48% and 62.83%，and the total yields significantly increased by 11.62% and 30.23%，respectively. The length，width，thickness，and soaking stability of A. cornea in the first tide of fruiting body were greatly improved. The lowest contamination rate of A. cornea cultivated with eucalyptus sawdust was 1.48%. The fruiting bodies obtained from three substrates（eucalyptus sawdust，eucalyptus bark and miscellaneous sawdust） contained 17 amino acids，of which 7 amino acids were essential，with 44.04%，41.49% and 41.89% accounting for total amino acids，respectively. The contents of essential amino acids in fruiting bodies under the experiment were higher than that of Food and Agriculture Organization of the United Nations/World Health Organization （FAO/ WHO） model，but lower than that of ovalbumin model. Lysine was the first limiting amino acid among all the essential amino acids. Meanwhile，all three types of A. cornea were rich in various flavor amino acids，and content of bitter amino acid was the highest. According to the evaluation criteria of amino acid，the score of ratio coefficient of amino acid（SRC） and essential amino acid index（EAAI） of A. cornea on eucalyptus sawdust were the largest，being 58.00 and 86.19，respectively. The amino acid composition of A. cornea cultivated on eucalyptus sawdust was closer to that of whole egg protein and had higher nutritional value. Texture properties results indicated that eucalyptus sawdust had better hardness （50.24 N），cohesiveness （0.535），springiness （0.866 mm），gumminess （29.89 N） and chewiness （23.94 mJ）. There was significant or extremely significant （P<0.01） correlation between the quality indexes in A. cornea on different cultivation substrates. Principal component analysis showed that the the quality of A. cornea on three cultivation substrates from high to low was as follows：eucalyptus sawdust>eucalyptus bark>miscellaneous sawdust. 【Conclusion】A. cornea cultivated on eucalyptus sawdust present higher nutritional value and edible quality，which can be used as the main cultivation substrate.