The effects of different processing conditions on biogenic amine formation and some qualitative properties in pastırma

Investigation of textural and physicochemical changes during the manufacturing process of pastırma, a dry-cured meat product

The changes in textural and physicochemical properties and stability of meat proteins during the production of pastırma were studied. Samples taken at different production stages (raw material, curing, first drying, second drying and final product) were analyzed. The pH decreased at the end of the curing but increased after the first and second drying. While moisture content and water activity decreased throughout the pastırma production, salt content and Thiobarbituric acid-reactive substances (TBARS) increased. Production stages affected the free fatty acids, residual nitrite content and color parameters (P < 0.01). These results showed that considerable physicochemical changes occurred in the production stages of pastırma. The denaturation temperatures for myosin and actin decreased at the end of the curing, however, no denaturation peak for myosin was observed in the later stages. Hardness, cohesiveness and chewiness increased throughout the pastırma production. Warner-Bratzler (WB) shear force increased at the end of the first drying and in the final product. These results are important in terms of obtaining the desired textural properties in the final product. Also, remarkable correlations were detected among the determined properties during the manufacturing process. The study provided considerable findings for the development of industrial pastırma production.

The effects of curing agents on the proteolysis and lipid oxidation of pastırma produced by the traditional method

In the study, the effects of nitrate and/or nitrite (150 mg/kg KNO₃, 300 mg/kg KNO₃, 150 mg/kg NaNO₂, and 150 mg/kg KNO₃ + 150 mg/kg NaNO₂) on proteolytic changes (free amino acid composition, SDS-PAGE) in pastırma were investigated. Pastırma samples were also analyzed in terms of some qualitative (pH, a_w, TBARS, residual nitrite, salt) properties. The lowest total free amino acid content (1818.3 mg/ 100 g DM) was observed in the combination of 150 mg/kg KNO₃ + 150 mg/kg NaNO₂, while the highest content (2847.49 mg/ 100 g DM) was observed in 150 mg/kg KNO₃. Although the pastırma groups generally exhibited similar SDS-PAGE profiles, differences were detected at some band intensities. The lowest TBARS value (22.24 μmol MDA/kg) was observed in 150 mg/kg KNO₃ + 150 mg/kg NaNO₂. As a result, the use of 150 mg/kg KNO₃ in the pastırma curing process causes more intense proteolysis.

Nitrite reduction in fermented meat products and its impact on aroma

Fermented meat products are important not only for their sensory characteristics, nutrient content and cultural heritage, but also for their stability and convenience. The aroma of fermented meat products is unique and its formation mechanisms are not completely understood; however, the presence of nitrite and nitrate is essential for the development of cured aroma. The use of nitrite and nitrate as curing agents in meat products is based on its preservation activity. Even though their presence has been associated with several risks due to the formation of nitrosamines, their use is guarantee due to their antimicrobial action against Clostridium botulinum. Recent trends and recommendations by international associations are directed to use nitrite but at the minimum concentration necessary to provide the antimicrobial activity against Clostridium botulinum. This chapter discuss the actual limits of nitrite and nitrite content and their role as curing agents in meat products with special impact on dry fermented products. Regulatory considerations, antimicrobial mechanisms and actual trends regarding nitrite reduction and its effect on sensory and aroma properties are also considered.

Quality characteristics of cold-dried beef slices

In this study, salted and pasteurized beef slices were dried to approximately 40% water content at different low temperatures (10, 15 and 20 °C) and air flow rates (1, 2, 3 and 4 m/s) and the quality characteristics of the cold-dried beef slices were investigated. The TBARS values of cold-dried slices increased from 42.01 to 54.54 μmol MDA/kg with the increase in drying temperature and from 27.29 to 67.79 μmol MDA/kg with the increase in air flow rate indicating that low temperature and low air flow rate can help to avoid the lipid oxidation. Low drying temperature was also found to impact on the color of cold-dried slices. Additionally, it was determined that the microbiological quality of cold-dried slices decreased as the temperature increased from 10 to 20 °C and air flow rate increased from 1 to 4 m/s. Finally, the slices dried at 10 °C and 3 m/s had higher sensorial property scores. Consequently, low drying temperature and high air flow rate could enhance the quality of dried beef slices.