Effects of heating on cell growth-promoting activity and nutritional composition of porcine placenta extract

Porcine placenta extract (PPE) is typically autoclaved at 121°C for sterilization, yet the specific effects of heating on its properties remain unclear. This study investigated temperature-dependent changes in PPE to identify optimal sterilization conditions that preserve its nutritional and functional integrity. To minimize the loss of bioactive components, we explored a 'mild heat' approach inspired by dairy pasteurization. Based on reported thermal processing conditions in dairy science, PPE was prepared using the conventional method at room temperature, and heated at 50, 60, 70, 80, 90, and 100°C for 20 min. The results indicated that unheated extract increased the growth of dermal fibroblast cells by 130 % compared with the control treatment (culture medium without PPE). However, heating at 70, 80, 90, and 100°C significantly reduced the cell growth-promoting effects to 82, 75, 72, and 62 %, respectively ( P < 0.05). Heating temperatures above 60°C significantly reduced the protein and FGF1 contents of PPE ( P < 0.05). These findings demonstrate that, to preserve protein level, particularly FGF1, and cell growth-promoting function in PPE, thermal sterilization should be performed at temperatures below 70°C.