Contents of nutrients in ultra-fine powders of steamed and lyophilized mature silkworms generated by four silkworm varieties

Abstract Several health-promoting effects of mature silkworms, Bombyx mori , have recently been reported. Interestingly, those reports suggested that powders of steamed and lyophilized mature silkworms (SMSPs) generated from different varieties with unique cocoon colors may have additional and distinctive pharmacological activities. In our recent studies, “fine” SMSPs (fSMSPs) with an average particle size of 10 μm had higher contents of nutrients and enhanced their pharmacological activities, compared with “coarse” SMSPs (cSMSPs) with an average particle size of 120 μm. Recently, a new pulverizing method for SMSPs reducing their particle size to around 1.1 μm has been developed to generate “ultra-fine” SMSPs (ufSMSPs). In the present study, we analyzed and compared the contents of nutrients in the ufSMSPs generated by four different varieties with unique cocoon colors; white jade, yellow, pistachio, and red. The contents of almost all nutrients detected in the four ufSMSPs showed significant differences ( p