Quality Control Methods and Qualimetry for Livestock Product Analysis
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Quality control of food raw materials and finished products is the practice of monitoring chemical composition and physico-chemical properties throughout processing, so that the final product meets defined standards. During the processing of technological raw materials into finished goods, both the chemical composition and the physico-chemical properties of the material change. Monitoring those properties during the technological process makes it possible to influence the quality indicators of the final product directly. 
Why is quality control important in animal-product processing?
Quality control of livestock products is a crucial stage in this branch of the food industry. The instruments used to determine the composition and physico-chemical properties — the quality — of food products are called analyzers, while the general methods of product quality control are known as qualimetry methods. The methods for analyzing the composition and properties of products and raw materials fall into two main groups: selective and integral.
What are selective methods of quality analysis?
Selective methods are simple and reliable, and they determine individual properties of a substance. These methods are used when product quality is assessed by specific electrical conductivity, density, buoyant force, and similar measures. In other words, a selective method works when the quality indicator of the product is a direct function of a single physical quantity.
What are integral methods of quality analysis?
Integral methods are characterized by the dependence of measurement results on several properties and on the overall composition of the product. The quality of bread, for example, is made up of many indicators: the quality of the flour and other components, temperature regimes during baking, external appearance, and geometric dimensions. No single physical measurement captures this kind of multi-factor quality, so an integral approach combines several measured characteristics.
How are composition and property analyzers classified?
Instruments for determining composition and physico-chemical properties are classified by several criteria: by analysis method, by the properties of the medium being measured, by their design and construction, and by the type of output signal. This classification helps match a given analyzer to the specific raw material and processing stage where it will be used.
Which measurement methods are used in food-industry control?
Automatic control of the composition and physico-chemical properties of media in the food industry relies on a range of established measurement methods. The most widely used are:
- Conductometric — based on the electrical conductivity of the medium;
- Potentiometric — based on measuring electrode potential;
- Polarographic — based on current–voltage characteristics during electrolysis;
- Dielcometric — based on the dielectric properties of the substance;
- Optical — based on the interaction of light with the medium;
- Radioisotope — based on the interaction of ionizing radiation with the material;
- Mechanical — based on physical properties such as density or viscosity.
Choosing the appropriate method depends on the nature of the raw material, the property being monitored, and whether a selective or integral assessment of quality is required.
