超微粉碎及螺杆挤压对大豆豆渣粒度和加工性质的影响

Effects of Ultrafine Comminution and Screw Extrusion on Particle Size Distribution and Processing Properties of Okara

鲜豆渣经烘干后,采用直接超微粉碎和螺杆挤压-超微粉碎联用技术处理,研究这两种加工方式对豆渣粒度和加工性质的影响。结果表明,直接超微粉碎处理的豆渣与普通粉碎处理的豆渣相比具有良好的粒度分布和加工性质,直接超微粉碎10、20、30min和60min的豆渣D50的粒径均在10μm以内,粉碎时间20min最为适宜,在此条件下,豆渣分散性最佳,过滤截留物为4.5g,水溶性达到21.34%,同时持水力和膨胀力也较高。螺杆挤压-超微粉碎联用处理的豆渣,虽然色泽会变暗,但分散性会明显优于直接超微粉碎的豆渣,截留物质量仅为1.53g,更适合冲调产品。

In this study,fresh okara was dried and subjected to ultrafine comminution alone or screw extrusion followed by ultrafine comminution.We established the optimum conditions for drying fresh okara and explored the effects of ultrafine comminution alone and in conjunction with screw extrusion on the particle size distribution and processing properties of okara powder.Ultrafine okara powder had better particle size distribution and processing properties than ordinary okara powder.The average particle sizes（D50） of ultrafine powder samples obtained after comminution for 10,20,30,60 min were less than 10 μm and the 20-min ultrafine powder sample showed the best dispersibility,a water solubility of 21.34% and enhanced water-holding capacity and expansibility and yielded 4.5 g of filtration residue,suggesting that the optimum comminution time was 20 min.The combined use of screw extrusion and ultrafine comminution,although causing the color of okara to darken,could notably increase the dispersibility of okara powder in comparison with ultrafine comminution alone,and only 1.53 g of filtration residue was obtained from the resulting power,thereby being more suitable for the production of instant food products.