Changes in Myofibrillar and Sarcoplasmic Proteins in Salami Processing Added withLactobacillus Sakei/Staphylococcus CarnosusAccording to Modulated Differential Scanning Calorimetry and the Color Profile

Abstract

Changes in the thermal and color profiles of the sarcoplasmic and myofibrillar protein fractions were analyzed during the fermentation and ripening processes of salami added with Lactobacillus sakei and Staphylococcus carnosus using modulated differential scanning calorimetry, CIELAB and reflectance. The results of the pre and postfermentation stages for the myofibrillar and sarcoplasmic fractions showed a decrease in transition temperatures (Tm) without variation in the degradation enthalpy (ΔHd). Thus, the sarcoplasmic protein fraction in these stages showed Cp values between 0.18 and 1.0 J/gC while for myofibrillar was 0.22 and 0.07 J/gC. However, in the postripening stage, the ΔHd increased to 364.1 J/g for myofibrillar fraction and 1292 J/g for sarcoplasmic fractions. Seventh day corresponds to the turning point in L*, a decreasing trend was observed in L* and the reflectance percentage in postripening stage, which can reflect structural changes in proteins. Practical Applications This study facilitates a comparison of the changes in sarcoplasmic and myofibrillar protein fractions during three stages of salami processing, correlating these changes with the bacterial population dynamics focused on the behavior of a starter culture, pH and aw. Likewise, the possibility of using a methodology such as modulated differential scanning calorimetry and color to analyze protein changes in a complex matrix such as salami is intriguing.