Extending the performance shelf life of direct-salted block Gouda

Direct-salted, block Gouda has recently become a popular cheese that is made in the United States, mostly for export purposes. The dairy industry uses 2 types of manufacturing options for this cheese; stirred curd (SC) and milled curd (MC), and we wanted to explore if there were any differences in the properties of cheese made with these 2 different methods. We also investigated 2 options to help extend the performance shelf life and functionality of this direct-salted Gouda cheese: high-pressure processing (HPP) and the use of different storage temperatures. Batches (n = 4) of direct-salted Gouda cheese were produced using a reduced proteolytic coagulant (camel chymosin to help extend the shelf life) by both SC and MC Gouda cheese approaches. After 1 mo of ripening, cheeses were divided into 2 pressure groups: control (non-HPP) and HPP (600 MPa for 3 min), then stored at 3 different storage temperatures (-18, 0, or 4°C). Analyses were performed during storage up to 365 d. The pH of samples stored at 4°C and non-HPP treated increased significantly during storage. There was little change in the pH values for all the HPP-treated or non-HPP samples stored at 0°C or at -18°C. Starter and nonstarter bacteria counts were reduced by ∼3 and 5 log cfu/mL, respectively, by HPP. In the HPP-treated samples stored at 4°C, bacterial numbers slowly increased during the 365-d storage period. Proteolysis (pH 4.6 soluble N) was negatively affected by the use of lower storage temperature and HPP treatment. Dynamic small-amplitude oscillatory rheology indicated that cheese meltability (maximum loss tangent) was increased by HPP treatment, likely due to the small, immediate reduction in the insoluble calcium levels in cheese caused by HPP. Hardness decreased during cheese storage at -18°C, possibly due to some disruption in the body of the cheese (e.g., more brittleness) because of freezing/thawing. The length of shreds prepared from Gouda cheese greatly decreased during storage at 4°C and in frozen samples that were non-HPP treated. Shred length was mostly retained during the 365-d period in samples stored at 0°C and HPP treated. The MC cheese had a longer shred functionality shelf life than the SC cheese. Frozen Gouda cheese exhibited some loss of functionality during the long storage period. The combination of storage at 0°C and HPP treatment helped to retain high performance properties during the 365-d shelf life and could be another attractive option for extending the performance shelf life of direct-salted block Gouda cheese.