Utilisation of pumpkin seed (Cucurbita maxima) as a meat matrix preservative: Influence on colour and lipid stabilities

Abstract

Pumpkin (Cucurbita maxima) is a nutritious vegetable, with seeds rich in vitamins, phytochemicals, and antioxidants, but they are often discarded. This study aims to utilize pumpkin seeds as a preservative to enhance shelf life and colour stability in processed meats like mincemeat. Crude pumpkin seed extract (CPSE) was prepared by drying, methanolic extraction, and rotatory evaporation of the seeds. CPSE, analyzed for phytochemicals via RT-HPLC and antioxidant capacity, was added to meat at varying levels of 0 % (CON), 0 % with 200 ppm BHA (PCON), 2 % (2CPSE), 4 % (4CPSE), and 6 % (6CPSE) and evaluated for preservative indicators during 9 days of refrigerated storage. RP-HPLC analysis showed the extract had higher phenolic acid content (3.99 ± 0.02 mg/100 mg dry seed powder), predominantly p-hydroxybenzoic acid, with lower flavonoid content (0.05 ± 0.00 mg/100 mg). During storage, mincemeat treated with CPSE showed lower TBARS values, higher ferric-reducing power, and better colour and odour scores compared to CON and PCON groups over 9 days. Regression analyses depicted the preservative effects of sinapic acid, gallic acid, p-coumaric acid compounds found in CPSE on TBARS, colour and odour. Further, ABTS was found to strongly influence TBARS, colour and odour attributes during the 9-day refrigerated storage. In conclusion, the study demonstrated that pumpkin seeds can serve as effective food preservatives. Specifically, 2 % CPSE reduced lipid oxidation and improved mincemeat's sensory qualities, matching the efficacy of 200 ppm BHA, with even greater preservative effects at 4 % and 6 % CPSE levels.