The term “Osterized” refers to the intense, high-speed mechanical processing of food, typically associated with blending or pureeing. This method uses powerful rotating blades to transform whole ingredients into a smooth, liquid, or semi-liquid form. The act of blending involves complex physical and biological changes to food, causing structural alterations at a microscopic level.
The Physics of Pulverization
The transformation of solid food into a smooth consistency is governed by fluid dynamics and mechanical forces inside the blender jar. The high-speed rotation of the blades, which can exceed 20,000 revolutions per minute (RPMs), is the primary source of energy. This rotation establishes a vortex, drawing ingredients downward into the blades and ensuring continuous circulation of the food mass.
Ingredients are broken down through impact, friction, and high shear force. Shear force, a tearing or slicing action, reduces particle size as the food material is forced past the sharp edges of the blades. As the liquid mass circulates, the food particles are constantly subjected to these forces, leading to progressive pulverization. High liquid velocity can also lead to cavitation, where small vapor bubbles form and rapidly collapse, generating micro-shocks that further break down the material.
Cellular Disruption and Food Structure
The mechanical forces within the blender jar directly target the microscopic architecture of the food, particularly in plant-based ingredients. Plant cells are encased in rigid cell walls, primarily composed of cellulose, which acts as a protective barrier, trapping internal nutrients. Blending applies enough shear force to rupture these cell walls, a process known as cellular disruption.
Once the cell wall is breached, the internal components, such as the nutrient-rich cytoplasm and organelles, are released into the surrounding liquid mixture. This action creates the smooth texture of a puree, as the solid material is reduced to a fine suspension of tiny fragments. In mixtures containing both fat and water, this mechanical action facilitates the creation of a stable emulsion. While the fiber itself is not chemically destroyed, the processing reduces its particle size, leading to a thinner, less viscous final product.
Impact on Nutrient Availability
The structural changes that occur during blending have a direct consequence for how the body interacts with the food, mainly by influencing nutrient availability. By physically breaking down the cell walls, the blender essentially performs part of the digestive work outside the body, making the nutrients more accessible. This liberation of compounds, such as carotenoids and other phytochemicals trapped within the plant cell matrix, leads to an increase in their bioavailability, meaning a greater percentage can be absorbed into the bloodstream.
The mechanical breakdown of fiber results in a material that is already substantially processed, which can reduce the need for extensive chewing and subsequent mechanical breakdown in the stomach. While the total amount of fiber remains the same, its altered structure may reduce the physical bulk that slows down digestion, potentially leading to a quicker absorption of sugars and other nutrients. A trade-off to the increased surface area is a risk of oxidation for sensitive vitamins, such as Vitamin C. However, nutrient loss due to oxidation is often minimal if the blended product is consumed shortly after preparation.