Exploring in vitro gastrointestinal digestion of myofibrillar proteins at different heating temperatures

The effects of different heating temperatures (40-115 degrees C) on the structure, oxidation, and digestibility of beef myofibrillar protein were investigated. Reductions in the number of sulfhydryl groups were observed, together with gradual increases in the number of carbonyl groups, indicating oxidation of the protein by the increased temperatures. At temperatures between 40 degrees C and 85 degrees C, beta-sheets were converted to alpha-helices, and increased surface hydrophobicity showed that the protein expanded as the temperature approached 85 degrees C. These changes were reversed at temperatures over 85 degrees C, indicative of aggregation induced by thermal oxidation. Between 40 degrees C and 85 degrees C, the digestibility of the myofibrillar protein was increased, reaching a maximum of 59.5 % at 85 degrees C, after which it began to decrease. These results indicated that moderate heating and oxidation-induced protein expansion were beneficial to digestion while protein aggregation resulting from excessive heating is not conducive to digestion.

Automated summary

The study investigated the effects of different heating temperatures (40-115 degrees C) on the structure, oxidation, and digestibility of beef myofibrillar protein. The results showed that the protein underwent oxidation, with a decrease in sulfhydryl groups and an increase in carbonyl groups as the temperature increased. The protein underwent conformational changes and expanded at temperatures between 40 degrees C and 85 degrees C, but aggregated at temperatures over 85 degrees C due to thermal oxidation. The digestibility of the protein increased up to 85 degrees C and then decreased, suggesting that moderate heating and oxidation-induced protein expansion were beneficial to digestion, while excessive heating and protein aggregation were not.