Determining the level of oxidation of food oils and fats is of considerable interest to the food industry in quality control during the various phases of the production process. In fact the level of oxidation is an essential indicator of the genuineness of the product and of its state of conservation.

The FoodLab system (www.foodlab.cdr-mediared.it), developed by CDR (www.cdr-mediared.it), makes it possible to determine in just a few minutes the concentration of peroxides, acidity and soap in food oils and fats. Oil can be used directly raw, while solid fat must be melted at a temperature of approx. 60°C.

The Foodlab system is composed of an portable analyzer using sophisticated spectrophotometry and a series of dedicated reagents, developed by the CDR research laboratories, and using previously dispensed, non-returnable (disposable) cuvettes, requires neither specialized personnel nor reagent preparation.
The individual test is carried out by dispensing into a test tube a minimum predefined amount of sample, which, through appropriate reactives, develops a colorimetric reaction.
The reagents are composed exclusively of low toxicity substances, easily disposable, which allow the test to be carried out in any environment.
Actually chemichal analysis for food fats and oils quality control carried out using FOODLAB are:


Peroxides
The peroxide content present in a alimentary fat or oil attests to its state of primary oxidation and thus its tendency to go rancid. Unsaturated fatty acids, in fact, react with oxygen forming peroxides, which determine a series of chain reactions whose end result is volatile substances having the characteristic smell of rancidness. These reactions are accelerated by high temperatures and by exposure to light and oxygen. The lower the peroxides values, the better the quality of the alimentary oil and its state of preservation.


Acidity
The acid content in a alimentary fat or oil is given by the quantity of free fatty acids deriving from the hydrolytic going rancid of the triglycerides. This alteration occurs under unsuitable conditions of treatment and preservation of the fats and thus the acidity represents a basic indicator of the genuineness of the product. Substances with high water content, such as butter, are more subject to hydrolysis of the fats, and they can alter more easily, assuming the typical unpleasant smell and taste.


Soaps
Soaps are fatty acid salts obtained by the reaction of the free fatty acids with soda. Thanks to their solubility in water and insolubility in oil, they can then be separated from the fat using suitable procedures. Food industries use this procedure to lower a fat's acidity and improve its organoleptic characteristics.

p-Anisidine
Anisidine value (AnV) represents the level of non aldehids present in fat. The complex oxidation process can be summarized into two phases: in the first one fat acids react with oxygen and determine odourless compounds as peroxides; during the second phase the peroxides degrade into many substances as volatile aldehydes, responsible of the rancid odour and flavour, and in a not-volatile portion. p-Anisidine test gives a precise indication of this oxidation since it indicates the value of volatile and not-volatile aldehydes. Other tests, as TBA test, do not consider this volatile portion and therefore in some cases may determine a lower result.