In silico and in vitro analysis of heat treatment applications effects on bioactive human milk proteins

Bioactive proteins like lactoferrin and osteopontin in the composition of breast milk have numerous functions such as feeding, contributing to the growth and development, regulating immunity, supporting cognitive and physical development and protection of infants against infections. For various reasons, breast milk can be exposed to heat treatment or cold storage. In practice, breast milk is usually stored at room temperature (+20-25°C), at refrigerator temperature (+2-8°C) or in a deep freezer (-18°C) for certain periods or can be exposed to high temperatures of pasteurization process (30 min. at 62.5°C). Due to long-term storage, heating, pasteurization, freezing and thawing cycles, bioactive proteins in the composition of milk can be lost in significant amounts with lessened and their functions can be reduced. Studies on the subject generally focuses on enzyme activity (lysozyme, lactoperoxidase), iron and vitamin binding capacity (lactoferrin, haptocorrin), determination of immunoglobulin (sIgA) and antimicrobial activity (lactoferrin, lysozyme), monitoring of protein concentrations and evaluation of modifications of milk proteins after heat treatment. Although the effect of heat treatment on breast milk has been shown by some other studies, the structural changes of proteins are still not well known. This dissertation aims at revealing in vitro and in silico results of any structural changes of two bioactive proteins in breast milk, lactoferrin and osteopontin, upon exposition to different storage and heat treatment applications. This study is expected to contribute to the development of new preservation methods of breast milk and to the future studies to be carried out to reveal nutritional supplement recommendations that are beneficial for health and nutrition.