Autoxidation in milk rich in linoleic acid. II. Modification of the initiation system and control of oxidation.

The research explores factors that can initiate lipid oxidation in cow’s and mare’s milk with high polyunsaturated fatty acid content, and investigates methods to delay this process, such as the application of hydrogen peroxide and the addition of alpha-or gamma-tocopherols.

Essence of The Research

• The study delves deep into the aspects that could potentially set off lipid oxidation in cow’s and mare’s milk, both of which are rich in polyunsaturated fatty acids. The attention given to lipid oxidation arises from the fact that it typically leads to undesirable flavors and other quality degradations in milk.
• The research looks into several methods to delay or even entirely prevent the induction of lipid oxidation. These methods involve the addition of certain substances to the milk just after milking, such as hydrogen peroxide and alpha-or gamma-tocopherols.

Key Findings

• Starting off with cow’s milk, the experiment showed that introducing hydrogen peroxide right after milking in quantities slightly higher than required to eliminate ascorbic acid was successful in retarding the onset of oxidized flavors in the milk. This holds true specifically for cow’s milk that has a high content of linoleic acid.
• Even more advantageously, a combination of a hydrogen peroxide treatment followed by the subsequent addition of alpha-or gamma-tocopherols barred lipid oxidation in cow’s milk, irrespective of the inclusion of 0.1 mg Cu/l milk. In the instance of this combination treatment, copper did not result in lipid oxidation, which contrasted sharply with the case when hydrogen peroxide or alpha-or gamma-tocopherols were used individually in the presence of copper.
• However, in mare’s milk, the lipid and ascorbic acid content demonstrated significant resistance to oxidation. The use of copper, ethylenediamine tetraacetic acid, neocuproine, or hydrogen peroxide led to minimal loss of ascorbic acid and lipid oxidation.

Implications

• The findings of the research are crucial in various respects. Primarily, they highlight methods to keep the freshness and quality of milk high in polyunsaturated fatty acids intact by avoiding lipid oxidation.
• By pinpointing the circumstances under which the suggested methods turn ineffective, it provides further insights into the dynamics of lipid oxidation in milk and may help in refining these oxidation control methods.
• The differences found between mare’s and cow’s milk in terms of their vulnerability to oxidation will need further study to understand the exact factors leading to this difference, potentially illuminating the unique compositions and characteristics of different types of milk.