Define Homogenization or Blending of Food Sample?
Food homogenization - Liquid food samples are mixed manually before analyzing whereas solid foods are homogenized in a diluent to release microorganisms from food matrix and also to dispense clumps into smaller units. Blenders and Stomacher are commonly used to prepare the food sample for analysis. In Blender, revolving blades cut and mix the food with diluent. On the other hand, stomacher homogenizes specimen in a special sterile plastic bag by the vigorous back and forth mechanical action of 2 paddles. This shears the food specimen and the microorganisms are released into the diluent. Stomacher is generally preferred over blending because -
a) Normal operational time is less,
b) Homogenate can be stored in the stomacher bag in a refrigerator,
c) It is less lethal to microbes than blender, and
d) It homogenizes meat for dye reduction test which is not possible with the blender.