Changes in freshness parameters and the installation of alterative processes when butter becomes improperly for consumption were studied inducing fatty acid content, peroxide value (PV), iodine value (IV), acid value (AV), thiobarbituric acid reactive substances (TBARS) and the presence of epyhidrinic aldehyde.
The content of saturated fatty acids was higher (71.84%) than that of unsaturated fatty acids (27.09%), the main fatty acids presented in butter were butyric, miristic, palmitic, oleic and stearic acids.
Iodine index for butter stored under freezing conditions decreased significantly to the 8th month (P≤0.01), followed by a very significant decrease to the 9th month (P≤0.001), then the decrease was relatively slow until the 12th month, between the storage time and IV there was determined an inverse correlation (R=-0.972).
The advanced hydrolysis process was installed after about 30 days, acidity exceeded 2% (g oleic acid) (P≤0.01), the maximum permitted limit for fresh butter, between acidity values and storage time there was determined a perfect correlation (R=0.993). The induction period for butter stored under freezing conditions was about 8 months, propagation period was about 3 months, and the period of decline began in the 12th month when were formed the secondary compounds of oxidation, after 11 months the oxidative status of butter sample passed from primary to secondary state
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