Pressure effects on the heat-induced aggregation of equine serum albumin by FT-IR spectroscopic study: Secondary structure, kinetic and thermodynamic properties

Evaluation of key aroma compounds and protein secondary structure in the roasted Tan mutton during the traditional charcoal process

The traditional charcoal technique was used to determine the changes in the key aroma compounds of Tan mutton during the roasting process. The results showed that the samples at the different roasting time were distinguished using GC-MS in combination with PLS-DA. A total of 26 volatile compounds were identified, among which 14 compounds, including (E)-2-octenal, 1-heptanol, hexanal, 1-hexanol, heptanal, 1-octen-3-ol, 1-pentanol, (E)-2-nonenal, octanal, 2-undecenal, nonanal, pentanal, 2-pentylfuran and 2-methypyrazine, were confirmed as key aroma compounds through the odor activity values (OAV) and aroma recombination experiments. The OAV and contribution rate of the 14 key aroma compounds were maintained at high levels, and nonanal had the highest OAV (322.34) and contribution rate (27.74%) in the samples after roasting for 10 min. The content of α-helix significantly decreased (P < 0.05), while the β-sheet content significantly increased (P < 0.05) during the roasting process. The content of random coils significantly increased in the samples roasted for 0-8 min (P < 0.05), and then no obvious change was observed. At the same time, β-turn content had no obvious change. Correlation analysis showed that the 14 key aroma compounds were all positively correlated with the content of α-helix and negatively correlated with the contents of β-sheet and random coil, and also positively correlated with the content of β-turn, except hexanal and 2-methypyrazine. The results are helpful to promoting the industrialization of roasted Tan mutton.

Shockwave processing of beef brisket in conjunction with sous vide cooking: Effects on protein structural characteristics and muscle microstructure

We studied the effect of shockwave processing and subsequent sous vide cooking on meat proteins (molecular size and thermal stability) and muscle structures (molecular, micro- and ultrastructure). Beef briskets were subjected to shockwave (11 kJ/pulse) and were sous vide-cooked at 60 °C for 12 h. Shockwave processing alone decreased the enthalpy and thermal denaturation temperature of the connective tissue proteins (second peak in the DSC thermogram, p < 0.05) compared to the control raw samples, while the protein gel electrophoresis profile remained unaffected. It led to disorganisation of the sarcomere structure and also modified the protein secondary structure. More severe muscle fibre coagulation and denaturation were observed in the shockwave-treated cooked meat compared to the cooked control. The results show that shockwave processing, with and without sous vide cooking, promotes structural changes in meat, and thus may have the potential to improve the organoleptic quality of the tough meat cuts.

Glycation of bovine serum albumin with monosaccharides inhibits heat-induced protein aggregation

Glycation with Xyl/Gal could hinder the heat-induced BSA aggregation, and the hindrance effect was enhanced with high glycation degree.