Shelf-life extension of Paneer by a sequential supercritical-CO2-based process

The shelf-life of Paneer is limited to 1–2 days at room and 5–6 days at refrigeration temperature. This study was conducted to investigate the combined effects of supercritical-CO2 (SC– CO2) and a food-grade acid for the shelf-life extension of Paneer at room (25 ± 1 °C) and refrigerated (4 ± 1 °C) temperatures. Freshly prepared Paneer was subjected to SC–CO2 treatment at different pressures and temperatures in combination with acetic acid (AA) as a model acid to investigate their combined effects on the moisture content (Mw) and pH of the final product. Efficacy of the process was established by textural, viscoelastic, and microbiological analyses. The final Mw, pH, and water activity of Paneer was found to be 34.7 g/100g, 4.56, and 0.81, respectively. Textural and viscoelastic properties of treated samples remained well within acceptable range. Substantial microbiological stability was observed for treated Paneer for a storage period of 30 days. Although, the microbial evaluation was terminated at 30 days of storage, the samples stored under refrigeration showed consistently lower microbial counts for the same storage time. Overall, the findings show that this sequential treatment can be effectively used as a sustainable, clean-label, and non-thermal processing technology to extend shelf-life of Paneer and other similar dairy products.