Comparative Evaluation of Cold Plasma and GRAS Antimicrobials for Shelf Life Extension of Meat-Based Hummus

The present study was conducted to extend the shelf life and microbial safety of meat-based hummus using cold plasma technology, a novel non-thermal preservation method. Preliminary trials were carried out to optimize the product formulation and processing parameters. The optimized meat-based hummus formulation was developed by replacing 50% of chickpea paste with minced lamb meat cooked for 20 minutes. To evaluate the effectiveness of different antimicrobial strategies, four treatments were compared: control (no antimicrobial), T1 (0.4% sodium acid sulfate), T2 (0.1% sodium benzoate + 0.1% potassium sorbate), and T3 (cold plasma treatment at 0.7 cm layer for 3 minutes). Samples were stored under refrigeration and analyzed for physico-chemical and microbiological characteristics. Among treatments, T1 exhibited significantly (P<0.05) lower pH compared to control and other treatments, while the control showed the highest TBARS values throughout storage. Both pH and TBARS values increased significantly (P<0.05) in all samples from day 0 to day 20. Total plate count (TPC) remained significantly (P<0.05) lower in treated samples than in the control at the end of storage and within the permissible safety limits. For pathogen challenge studies, the samples were inoculated with Listeria monocytogenes (log 6.00 cfu/g) and monitored at 7-day intervals up to 21 days. Cold plasma treatment (T3) achieved a 3-log reduction in Listeria count immediately (day 0), whereas T1 and T2 showed delayed but effective antilisterial activity from the 7^th day onwards. Overall, cold plasma treatment demonstrated comparable efficacy to GRAS (Generally Recognized As Safe) antimicrobials and superior antilisterial activity, indicating its potential as an effective, non-chemical preservation method for extending the shelf life of meat-based hummus.