College of Food Science and Technology, Huazhong Agricultural University
本研究利用高能振动球磨技术制备核桃酱，研究不同球磨处理时间对核桃酱的粒径、质构、流变性能及微观结构的影响。结果表明，以核桃仁为原料，球磨处理不同时间（2、4、8、16、24 min），可以得到不同粒径与质地的核桃酱。球磨处理能有效降低核桃酱的粒径，球磨处理24 min后核桃酱平均粒径由79.89 μm下降到37.88 μm，整体下降了53%。球磨处理后的核桃酱是一种典型的非牛顿假塑性流体，表现为弹性固体特征，且具有正触变性。根据流变及质构测量结果可以看出，随着球磨处理时间的延长，核桃酱的凝胶强度、黏着性和粘聚力逐渐下降，流动性逐渐增强。其中，球磨处理8 min的核桃酱体系具有较高的粘弹性，适合加工为涂抹酱产品；球磨处理16 min和24 min的核桃酱流动性较强，粒径较小，适合作为沙拉汁的原材料。因此，高能球磨技术可作为一种制备核桃酱的技术，并可通过工艺改变调控核桃酱的流变学特性。
The walnut kernel was ball milled for different durations (2, 4, 8, 16, and 24 min) to develop walnut butter products, reduce the particle size and improve its rheological properties. The average particle diameter of walnut butter after ball milling for 24 minutes decreased from 79.89 μm to 37.88μm, by 53% overall. It was a typical non-Newtonian pseudoplastic fluid, which had the characteristics of viscoelasticity and positive thixotropy. The results revealed that the hardness and consistency of the walnut butter decreased, and the fluidity gradually increased during the ball milling treatment. The walnut butter ball milled for 8 minutes showed the higher viscosity and smaller in particle size, and was suitable for processing as a spreadable butter. As for ball milling process for 16 and 24 minutes exhibited the best fluidity and was suitable for the processing of salad sauce. Results could be useful in development of the walnut butter making process system design. Therefore, high-energy ball milling technology could be used as a technique for preparing walnut butter, and gradually change the rheological properties of finely divided walnut butter through the process.