利用米曲霉菌发酵水解制备无臭蚕蛹蛋白肽的工艺研究

Study on the Preparation of Odorless Silkworm Pupa Protein Peptide by Fermentation and Hydrolysis with Aspergillus oryzae

以脱脂蚕蛹粉为底物,通过诱导驯化获得一株具有高效水解能力的米曲霉菌分离株蚕20,35℃水解3 d分离株对蚕蛹蛋白的水解率达23.12%。GC-MS分析表明,蚕蛹蛋白水解物中含量较高的有11种挥发性成分,包括异丁酸、苯甲醛、2-十一酮、2-辛酮、3-辛酮、邻苯二甲酸二丁酯、2-十三酮、环氧乙烷、十八烷、十六烷、邻甲氧基苯酚,其中臭味成分主要是邻苯二甲酸二丁酯和异丁酸,而3-辛酮、2-辛酮和苯甲醛具有果香味。脱脂蚕蛹粉经蚕20分离株全细胞发酵水解后,蚕蛹蛋白水解物中邻苯二甲酸二丁酯和异丁酸的相对含量较未水解对照组分别降低3.37和0.88百分点,2-辛酮、3-辛酮和苯甲醛的相对含量分别增加7.90、3.90和0.80百分点,水解物的臭味强度显著减弱。水解温度和时间分别为35℃和3 d时,可进一步降低水解物的臭味强度。试验结果为利用米曲霉菌对蚕蛹蛋白进行全细胞发酵水解,生产无臭蚕蛹蛋白肽奠定了基础。

A strain of Aspergillus oryzae,silkworm 20,with high hydrolyzing ability was obtained by induction and acclimation based on the defatted silkworm pupa powder.The hydrolysis rate of silkworm pupa protein could reach to 23.12%after 3 d of hydrolysis at 35℃.The result of GC-MS analysis showed that there were eleven volatile components in the hydrolysates of silkworm pupa protein,including isobutyric acid,benzaldehyde,2-undecanone,2-octanone,3-octanone,dibutyl phthalate,2-tridecanone,ethylene oxide,octadecane,hexadecane and guaiacol.The main odor components were dibutyl phthalate and isobutyric acid,while 3-octanone,2-octanone and benzaldehyde had fruit fragrance.The defatted silkworm pupa powder was hydrolyzed by whole cell fermentation of silkworm 20.Compared with the unhydrolyzed control group,the relative contents of dibutyl phthalate and isobutyric acid in silkworm pupa protein hydrolysate decreased by 3.37 and 0.88 percentage points,respectively,while that of 2-octanone,3-octanone and benzaldehyde increased by 7.90,3.90 and 0.80 percentage points,respectively,and the intensity of odor of the hydrolysate decreased significantly.When the hydrolysis temperature and time were 35℃and 3 d,the odor intensity of hydrolysate could be further reduced.The results laid a foundation for the whole cell fermentation and hydrolysis of silkworm pupa protein with Aspergillus oryzae to produce odorless silkworm pupa protein peptide.