活蛹缫丝工艺对蚕蛹主要组分含量与性状的影响

Influence of Live Cocoon Reeling on Content and Property of Silkworm Pupa Main Components

活蛹缫丝是蚕茧不经过烘茧、煮茧直接缫丝的新工艺,从蚕蛹资源开发利用的角度,考察蚕蛹经过活蛹缫丝工艺各个流程处理后,其主要组分含量与性状变化。活蛹缫丝工艺中,机械脱衬造成蚕蛹质量损失约12.21%,但蚕蛹中蛋白质和油脂2种主要组分的比例无显著变化,质量比仍保持在1.20～1.23∶1。活蛹缫丝工艺各个流程取样制备蚕蛹蛋白的不良气味明显变淡,而理化性状则出现不同程度的变化,其中经缫丝和机械脱衬后的蚕蛹蛋白几乎完全变性,但缫丝后的蚕蛹蛋白的乳化性和溶解性最好。活蛹缫丝工艺各个流程取样制备蚕蛹油脂的化学性状(如酸价、碘值、过氧化值、皂化值等)也发生一定程度的变化,其中机械脱衬后蚕蛹油脂的酸价和过氧化值升高,不饱和度降低,使粗制蚕蛹油的品质下降。研究结果表明,活蛹缫丝工艺中的机械脱蛹衬与传统缫丝工艺机械脱蛹衬相比,同样会造成蚕蛹主要营养组分损失,并对蛹蛋白质和油脂的性状有不利影响,因此活蛹缫丝的蚕蛹仍不适于作为高档食品开发的原料。

Live cocoon reeling is a novel reeling technology without cocoon drying and cooking steps. From the perspective of developing and utilizing silkworm pupa resources, the influence of live cocoon reeling on content and property of silkworm pupa main components was investigated. It was found that, during live cocoon reeling, mechanical removal of pupal shirt led to about 12.21% loss of silkworm pupa mass but did not cause significant variation on mass ratio of protein to oil which was maintained at 1.20 -1.23： 1. Pupa protein samples prepared at various steps of live cocoon reeling had obviously lighter unfavorable smell. But mechanical and physical property of the pupa proteins was changed in vari ous degrees. Pupa proteins after reeling and mechanical removal of pupa shirt were almost completely denatured, though pupa proteins after reeling had the best emulsibility and solubility. Chemical properties （such as acid value, iodine value, peroxide value and saponification value） of pupa oil samples prepared at various steps of live cocoon reeling were changed in various degrees as well, After mechanical removal of pupal shirt, the acid value and peroxide value of pupa oil were increased and degree of unsaturation was reduced, leading to deterioration of crude pupa oil quality. These results indicate that, compared to mechanical removal of pupa shirt in traditional cocoon reeling, the mechanical removal of pupa shirt in live cocoon reeling could also lead to loss of main nutritional components in silkworm pupae and bring unfavorable effect to property of pupa protein and oil. Therefore, silkworm pupae from live cocoon reeling are still not suitable for development of high grade food products.