Food manufacturing companies have protocols in place for testing their products throughout the manufacturing process. This is done to ensure that products meet specifications and are safe for consumers to eat. Sensory evaluation panels are also used to determine whether consumers will like a particular product and whether they are able to distinguish it from a competing brand. The four tests that should be conducted on all commercial food products are nutritional, organoleptic, microbial and chemical.
Nutritional testing is conducted on finished food products in order to build the Nutrition Facts table for the product label. Tests are conducted to measure the fat, protein, carbohydrate and ash contents. The calorie content is then calculated from these test results. Nutritional testing requires specialised laboratory equipment and is commonly contracted out to independent laboratories that specialise in food analysis. An example of nutritional testing is the measurement of sugar using a titration method.
Food must be tested for bacteria before it can be released for sale commercially. This is the most important type of food testing because identifies food that could potentially risk the health of consumers. Microbial testing is usually done by quality control technicians that work within the food manufacturing facility. The most common microbial tests are those for E. coli, Salmonella, Listeria and Staphylococcus. The Food and Drug Administration (FDA) regulates the levels of bacteria allowed on commercial food sold in the United States. An example of microbial testing is the Gram stain, which is used to identify Gram negative and Gram positive bacteria.
Organoleptic testing is the evaluation of a food's taste, appearance, smell and texture. Food manufacturing companies host large sensory evaluation panels to conduct organoleptic tests on their food products, while quality control technicians conduct routine tests for every new batch of product manufactured. Organoleptic testing is important for ensuring that the food is appealing to consumers and that it maintains batch-to-batch consistency. An example of organoleptic testing is the evaluation of a yoghurt's smoothness in the mouth.
Chemical testing is done to measure vitamin and mineral levels for the Nutrition Facts table and to identify possible chemical contaminants or allergens in the food product. These tests require expensive analytical equipment and are commonly contracted out to external laboratories. An example of chemical testing is the quantification of caffeine in coffee bean by high performance liquid chromatography (HPLC).