FLAVIA POP INSTALLATION OF HYDROLYSIS AND OXIDATION PROCESSES IN ANIMAL FATS DURING REFRIGERATION AND FREEZING STORAGE
Physico-chemical characteristics and freshness indicators of cow butter during refrigeration (2 ... 4oC) and freezing (-15 ...- 18oC) storage were studied. Alteration (hydrolysis and oxidation) of food is responsible for the degradation of sensory quality, nutritional value and even the formation of toxic substances such as peroxides, which requires intimate knowledge of these processes and taking appropriate measures to avoid losses that can be registered. Research motivation was the determination of physico-chemical indicators in fresh milk fat, and the moment when occur changes in organoleptic and physico-chemical parametres of butter stored under refrigeration and freezing, making it unsuitable for human consumption. Changes in freshness parameters and the installation of alterative process when butter becomes improperly for consumption were studied inducing fatty acid content, acidity, peroxide index, iodine index 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 present in butter were butyric, miristic, palmitic, oleic and stearic acids. There was an increase of titrabile acidity during storage, butter hydrolysis was installed after 15 days under refrigeration and after one month under freezing conditions. Results showed that butter is resistant to oxidation, epyhidrinic aldehyde was shown after 6 months of storage under refrigeration and after 11 months in freezing conditions.