Objective evaluation of food
Objective evaluation of foods involves instrumentation, and use of physical and chemical techniques to evaluate food quality.
Objective testing uses equipment to evaluate food products instead of variable human sensory organs.
Such tests of food quality are essential in the food industry, especially for routine quality control of food products.
An objective test measures one particular attribute of a food rather than the overall quality of the product.
Therefore, it is important to choose an objective test for food quality that measures a key attribute of the product being tested.
For example, orange juice is both acidic and sweet; thus suitable objective test for this product would be measurement of pH and measurement of sugar content.
These tests could be of no value in determining the quality of a chocolate chip cookie.
A suitable test for cookie quality might include moisture content or the force required to break the cookie.
There various objective tests available for monitoring food quality. Fruits and vegetables may be graded for size by passing them through apertures of a specific size.
Eggs are also graded in this manner, and consumers may choose among six sizes including small, large or jumbo sized eggs.
Flour is graded according to particle size, which is required to pass through sieves of specific mesh size.
Color may be measured objectively by several methods, ranging from simply ,matching the product to colored tiles to using the Hunterlab color and color difference meter.
The color meter measures the intensity, chroma and hue of the sample and generates thee numbers for the sample under test.
Thus small changes in color can be detected. This method of color analysis is appropriate for all foods.
For liquid products, such as apple juice, a spectrophotometer can be used to measure color.
A sample is placed in the machine and a reading is obtained, which is proportional to the color and/or the clarity of the juice.
Objective evaluation of food
