INRA, UR638 Processus aux Interfaces et Hygiène des Matériaux, F-59651 Villeneuve d'Ascq, France.
J Food Sci. 2011 Jun-Jul;76(5):E384-91. doi: 10.1111/j.1750-3841.2011.02183.x. Epub 2011 May 4.
Many food recipes entail several homogenization steps for solid particles in hot or cold viscous liquids, such as pureed fruit and sugar, jam or sauce with mushroom pieces. Unfortunately, these unavoidable processes induce damage to the solid particles. To date, little is known of the extent and nature of the damage caused. Consequently, few clear guidelines are available for monitoring solid particle integrity when mixing solid/liquid suspensions in an agitated tank. In this study, an attempt is made to quantify the impact of various physical parameters including the influence of the rotational speed of the impeller and the processing time on particle attrition, when a suspension of large visco-elastic particles in a highly viscous fluid is mixed under isothermal condition. Pectin gel particles were immerged in a viscous liquid and homogenized for various times and rotational speeds, while the evolution of the particle's morphological parameters was monitored. Then, a set of dimensionless numbers governing the attrition mechanism is established and some empirical process relationships are proposed to correlate these numbers to the morphological characteristics and mass balance ratios. From the conditions observed, it is clear that 2 dimensionless ratios could be responsible for a change in the damaging mechanisms. These 2 ratios are the Froude and impeller rotation numbers. Finally, in the conditions tested, mass balance ratios appear to be mainly sensitive to the impeller rotational number, while the shape ratios are both impacted by the Froude and impeller rotational numbers.
Damage to solid particles suspended in a stirred vessel reduce the final product quality in industrial cooking processes. Examples of this are fruit in jam or sauces with mushroom pieces. The attrition phenomenon was measured and the influences of the impeller rotational speed and processing time were evaluated quantitatively in function of dimensionless numbers. This study contributes key elements for the monitoring of damage to solids with a view to retaining solid integrity.
许多食物食谱需要对热或冷粘性液体中的固体颗粒进行多次均化步骤，例如果泥和糖、带有蘑菇块的果酱或酱汁。不幸的是，这些不可避免的过程会对固体颗粒造成损害。迄今为止，人们对所造成的损害程度和性质知之甚少。因此，在搅拌罐中混合固/液悬浮液时，很少有明确的指导方针可用于监测固体颗粒的完整性。在这项研究中，尝试量化各种物理参数的影响，包括搅拌器转速和加工时间对颗粒磨损的影响，当大粘弹性颗粒悬浮在高粘性流体中时，在等温条件下进行混合。果胶凝胶颗粒浸入粘性液体中，并在不同的时间和转速下进行均化，同时监测颗粒形态参数的演变。然后，建立了一组控制磨损机制的无因次数，并提出了一些经验过程关系，将这些数与形态特征和质量平衡比相关联。从观察到的条件可以清楚地看出，有 2 个无因次数可以负责改变破坏机制。这 2 个比率是弗劳德数和搅拌器旋转数。最后，在所测试的条件下，质量平衡比似乎主要对搅拌器旋转数敏感，而形状比都受到弗劳德数和搅拌器旋转数的影响。
悬浮在搅拌容器中的固体颗粒的损坏会降低工业烹饪过程中最终产品的质量。例如果酱中的水果或带有蘑菇块的酱汁。测量了磨损现象，并根据无因次数定量评估了搅拌器转速和加工时间的影响。本研究为监测固体损坏提供了关键要素，以期保持固体的完整性。
